Идентификация Jc Типы, Материалы, Чертежи
Идентификация Jc Типы, Материалы, Чертежи
Идентификация Jc Типы, Материалы, Чертежи
Types
Material Codes
Drawings
John Crane
Training Center
Copyright© 1993 John Crane
Published by John Crane
6400 West Oakton St., Morton Grove, Illinois 60053 U.S.A.
All right to illustrations and text reserved by John Crane. This work may not be copied, reproduced, or
translated in whole or in part without written permission of John Crane, except for brief excerpts in connection
with reviews or scholarly analysis. Use with any form of information storage and retrieval, electronic
adaptation or whatever, computer software, or by similar or dissimilar methods now known or developed in
the future is also strictly forbidden without written permission of John Crane.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Seal design and Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Seal Heads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Mating Rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Ancillary Seal items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Auxiliary Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Application factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Seal Design Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Seal Heads and Cartridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Mating rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Material Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Selection Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Carbon Graphite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Ceramics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Elastomeric Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Fluoropolymer Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Miscellaneous Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Material Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Packaging and Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Part Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Drawings and Booklets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Addenda
No. 1 American Petroleum Institute Standard 610 . . . . . . . . . . . . . . . .57
No. 2 American Petroleum Institute Standard 682 . . . . . . . . . . . . . . . .59
No. 3 John Crane Flexibox Identification System . . . . . . . . . . . . . . . . .62
No. 4 John Crane Safematic Identification System . . . . . . . . . . . . . . .66
No. 5 John Crane Sealol Identification System . . . . . . . . . . . . . . . . . .69
No. 6 John Crane 5 Symbol Identification System . . . . . . . . . . . . . . . .75
No. 7 John Crane 7 Symbol Identification System . . . . . . . . . . . . . . . .80
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Seal Identification 1
Introduction
In recent years John Crane Inc. has brought together several mechanical shaft seal companies. Each
company had its own system of product identification. The identification system of each company remains
intact. As new seal drawings are made the John Crane identification system will be used. Many products are
in the inventories of John Crane and its customers under the previous systems of identification. Because of
the existing inventories, personnel involved with mechanical seals will need to be familiar with the new and
old systems of identification. This booklet explains the various systems of identification.
2 Seal Identification
Seal Design and Function
To understand the identification systems, it is necessary to know the function of a mechanical shaft seal as
an assembly, and the function of the individual components in the assembly. A mechanical shaft seal is a
device for closing a gap and creating a fluid tight joint between equipment components. The equipment
components most often are a moving shaft and a stationary housing. The shaft moves within the stationary
housing. An annulus is necessary in the housing for the shaft to pass through. Fluid contained in the housing
can leak through the annulus. Mechanical shaft seals are designed and engineered to seal the annulus.
There are two categories of sealing: dynamic and static. Dynamic sealing takes place between components
that are in relative motion to each other, as with a moving shaft and stationary housing. That movement could
be rotary or reciprocating. Static sealing takes place between components that are stationary to each other,
as with a stationary housing and a gland plate.
Mechanical shaft seals consist of two basic units; a stationary unit and a rotating unit. These two units are
known as seal heads and mating rings. A mechanical shaft seal may have ancillary items such as sleeves
and gland plates. A sealing system includes the mechanical shaft seal with auxiliary equipment that
enhances the environment in which the seal operates. An example of a seal assembly with the individual
components noted is shown in Figure 1 below.
1 Mating Ring
2 Seal Head Assy.
5 3 Sleeve
4 Collar
5 Gland Plate
6 Flush Injection
7 Quench Injection
9
11 6 8 Throttle Bushing
9 Setting Device/Clip
10 Set Screw
7
11 Gland Plate Gasket
12 Sleeve O-Ring
12 2 1 3 8 4 10
Seal Heads
A seal head is an assembly of several components and is the flexible side of the seal that accommodates
any radial or axial equipment and operational motions. The majority of seal design variations are found in the
seal head. Each variation constitutes a new seal type. There are currently over 225 seal types at John Crane
Inc. The vast array of applications requires this number of seal types. Applications also require variations in
the component material.
Seal Identification 3
Each seal type can be categorized into one of two categories: pusher type and non-pusher type.
Pusher type seals have secondary seals that are hydraulic packing rings. The hydraulic packing rings are
totally dynamic and are activated by pressure or shaft movement. These secondary seals are dynamic
o-rings, wedges, v-rings, and u-cups. Non-pusher type seals have secondary seals that are partially dynamic
and partially static. These secondary seals include elastomeric, PTFE, and metallic bellows and compression
rings. Sealing occurs in the bellows static section. Flexibility occurs in the bellows dynamic section. The
terms “pusher” and “non-pusher” do not refer to the assembly springs.
Other variations of seal heads are used to categorize the seal type. The seal head pressure capabilities can
be designated as hydraulically balanced or unbalanced. The seal head may be rotating with the shaft or be
held stationary in the gland plate. The seal head may have a single spring or multiple spring arrangement.
The assembly may be caged in a retainer, or uncaged. The application may require a single seal head or
multiple seal heads.
Seal heads are assemblies consisting of: secondary seals, primary rings, springs, retainers, discs, drive
bands, collars, and anti extrusion rings. Each component has a function within the seal head assembly.
Those functions are as follows:
Primary Rings
Primary rings provide a platform for a lapped flat sealing surface that seals perpendicular to the shaft. The
primary ring seals against another lapped flat surface, on the mating ring. Primary rings float within the
assembly to provide flexibility to the assembly. Primary rings are made of many materials. The application will
dictate the material selected, however since the primary ring seals dynamically at its lapped flat surface it
must be of a heat and wear resistant material. There are numerous primary ring designs resulting from the
application factors. The primary ring must be sealed either on its inner or outer diameter with a secondary
seal.
Secondary Seals
The function of a secondary seal is determined by its position in the assembly. In rotating seal head
assemblies the secondary seal seals the primary ring to the shaft or sleeve and allows the primary ring to be
flexible. In stationary seal head assemblies the secondary seal seals the primary ring to the retainer or
housing and allows flexibility. Secondary seals are manufactured in elastomeric, fluoropolymer, fiber, and
metallic materials. As previously explained, these include dynamic o-rings, wedges, v-rings, and u-cups in the
pusher category. In the non-pusher category they are elastomeric and metal bellows or compression rings.
Secondary seals are used to statically seal mating rings into a gland plate or sleeve adapter. The tight fit of
the secondary seal also prevents ring rotation. O-rings, flat gaskets, or wide gasket rings are used. Sleeves
are sealed statically to the shaft with a secondary seal such as an o-ring or flat gasket. Gland plates are
sealed statically to the equipment housing with secondary seals. The static secondary seals for sleeves and
gland plates are often referred to as “tertiary seals”.
Springs
Springs perform three essential functions. For inside mount seal heads the springs provide a closing force to
the primary ring in the absence of seal chamber pressure or low seal chamber pressure. For outside
mounted seal heads, the springs and hydraulic balance are the source of closing force to the primary ring.
Springs compensate for equipment or seal head misalignment, maintaining seal face perpendicularity to the
shaft. Springs are made of metal materials. Compression rings that provide a spring like action are made of
elastomeric materials. The spring designs commonly used in seal assemblies are coil and wave springs.
4 Seal Identification
Metal bellows assemblies provide a spring like action, in addition to performing as a secondary seal.
Retainers
Retainers have several possible functions. The exact functions are dependent upon the seal head type and
the components contained. Retainers act to unitize all of the components into one assembly. The retainer
allows for ease of handling and installation. Retainers are a modification of a spring collar that provides a
surface for springs to be compressed against. Retainers provide a platform for positive drive mechanisms
and aid in the alignment of primary rings. Retainers are manufactured of metallic materials. As with other
components, the retainer design is a result of its function.
Miscellaneous Hardware
The function and design of the assembly hardware varies by the item and its position in the assembly. Drive
bands, pins, keys, and screws provide positive drive to the assembly. Drive mechanisms allow or restrict
axial or radial motions. Collars provide a surface for spring compression. Spring holders align the spring with
the shaft and prevent unwinding by centrifugal force . Spring adapters transmit spring tension to the retainer.
Setting devices set the installation position of the seal. Further information about drive mechanisms is
provided in the booklet: Threaded Fasteners, MMTC 311.
Mating Rings
Mating rings are independent rings that provide a platform for a lapped flat sealing surface, sealing
perpendicular to the shaft centerline. Mating rings do not provide flexibility to the assembly, but do provide
guidance to the flexible primary ring. When held stationary, the mating ring is an economical removable wear
area of the end or gland plate. It is sealed in position by a secondary seal. When adapted to a rotating shaft it
is an economical removable wear area of the sleeve and adapter. The primary ring of the assembly seals
against the mating ring. The mating ring is usually made of a material that is harder than the primary ring
material, its rigidity then guides the flexible primary ring. As a result of application and material variations,
there are several design variations of mating rings. The most common variations are: stationary mating ring
in the housing for process equipment, or mating rings that rotate with the shaft for high speed, misaligned, or
assembly line applications.
Ancillary items include sleeves, gland plates, pumping rings, and drive collars. The design of the equipment
the seal is applied to or the seal type dictates the use of these ancillary items.
Sleeves
The original and primary function of a sleeve is to be a removable wear area of the shaft. Sleeves were
originally used with mechanical packing ring sets because of packing wear. Wear which can result from a
dynamic secondary seal is located on the sleeve rather than the shaft. It is more economical to replace the
sleeve than the shaft. Sleeves are made of metallic materials in most cases. They may be of a synthetic
material for pH extreme applications. Sleeves unitize and drive the seal head assembly in a cartridge type
arrangement. Sleeves adapt mating rings to the shaft. Sleeves may be manufactured to provide a surface for
spring compression. They are also manufactured to provide a setting step for installing the seal head
assembly.
Seal Identification 5
Gland Plates
Gland plates may have several functions, depending upon the seal type. All gland plates close and seal the
seal chamber. Gland plates hold and align the mating ring or seal head. The gland plate may also provide
connection ports for flush, quench, and gas injections. Drain and vent ports may also be located in the gland
plate. For cartridge type assemblies the gland plate unitizes the assembly and provides installation setting
and alignment device positions.
Pumping Rings
Pumping rings are used to force liquid to flow from the seal chamber to an outside piece of auxiliary
equipment such as a heat exchanger or reservoir. The operating principles of a pumping ring are very similar
to those of a pump impeller. The types of pumping rings used by John Crane are: axial flow, radial flow, and
centrifugal flow. Pumping rings are usually mounted directly on the seal assembly and rotate with the
assembly. The design of the pumping ring, speed of operation, fluid, and system piping determines the output
of the ring.
Drive Collars
Drive collars are located outside of the gland plate on cartridge type seal assemblies. The collar locks the
sleeve and rotating assembly to the shaft. The collar also positions the seal assembly on the shaft axially for
the correct seal head compression.
Auxiliary Equipment
Auxiliary equipment provides a suitable environment for the mechanical seal to operate in. Mechanical seal
performance and longevity is enhanced when they operate in a cool, clean, well lubricated environment.
Auxiliary equipment is manufactured by John Crane Lemco. Auxiliary equipment includes reservoirs,
pressure lubricators, heat exchangers and their associated hardware. Auxiliary equipment is usually not
included in the identification systems for mechanical seals. Further information about auxiliary equipment is
provided in the booklet: Circulation Systems for Single and Multiple Seal Arrangements.
6 Seal Identification
Application Factors
A specific mechanical seal assembly constructed of a specific set of materials is chosen by carefully
considering the application factors. Seal designs and materials are tested under a variety of conditions in the
test laboratories. They are also tested in real field conditions in equipment operating in process plants. The
test results are recorded and used by the application engineering department for recommending the proper
seal design and materials.
The slightest change in operating conditions or additives in the fluid may require a totally different seal type or
set of materials. Consider one of the most common liquids sealed, water. Water can be varied easily by
changes in temperature, pressure, additives, purity, and source. Potable water is different from salt water,
which is different from purified water, demineralized water, borated water, sewage water, chlorinated water,
and sour water, etc. The factors usually considered for seal type and materials selection are listed below.
Temperature:
Operating range, Boiling Point, Freeze Point, Flash Point.
Pressure:
Operating range, Suction, Discharge, Seal Chamber.
Shaft Motion:
Rotary, Reciprocating.
Shaft Speed:
RPM (revolutions per minute), SPM (strokes per minute), FPM (feet per minute).
Dimensional Requirements:
Shaft or Sleeve diameter, Bore, Depth, Bolt Circle, Nearest Obstruction.
Operating Cycle:
Intermittent, Continuous.
Equipment Conditions:
Design, Materials, Horsepower, Alignments, Environment.
Plant Conditions:
Mechanical Maintenance, Operations, Warehousing.
Special Requirements:
Hazardous Service, Agency Controls.
Seal Identification 7
Seal Design Designations
Seal designs are assigned a numerical designation as a short-hand reference for a generic design
description. The designation is actually a code which identifies a specific seal design along with its type,
function, and geometry. At one time the type numbers were assigned in sequence with each new design.
Currently numbers are no longer assigned in sequence. The numbers are assigned by a consensus among
the Engineering and Marketing departments.
Prior to becoming unified with John Crane, Flexibox, Safematic, and Sealol had independent systems for
designating a seal design. In order to provide continuity, those designations remain intact. Totally
independent of any manufacturers identification system is a system developed by the American Petroleum
Institute (API). The API has two systems in place, one according to Standard 610 and one to Standard 682.
Explanations of these systems follow this booklet as addenda, pages 57 - 61.
Generic Description: A pusher type single arrangement seal head. An o-ring is the dynamic secondary seal.
The assembly consists of multiple coil springs, a unitizing retainer driven by set screws, and a hydraulically
balanced primary ring. An anti-extrusion ring is in the assembly to prevent the o-ring from extruding at the
primary ring. The hardware is interchangeable with another seal type. The cross section of the seal head is
reduced to fit narrow seal chambers. The mating ring and gasket, ancillary items, or any auxiliary equipment
are not noted in the example code.
Generic Description: Cartridge seal assembly series number 56. A non-pusher design, dual arrangement.
The seal heads consist of a naturally hydraulically balance assembly. For each seal the secondary seal is a
combination of a dynamic metal bellows and a static o-ring. The seal heads may be reversed. The assembly
includes the sleeve, gland plate assembly, and outside drive collar.
8 Seal Identification
Type and Variant Definitions
There are and can be several type codes and variant combinations. The unification of John Crane has
allowed for the best product technology to be offered and for the retiring of any redundant or less efficient
technology. Because of this many codes will not be used in the future. Common codes are listed as follows.
Type Definition
Seal Identification 9
Variant Definition
Cartridge Seal Type and Variant, Four Digit Scheme with suffix symbols.
37 As the first and second digit. Series type code for split seals.
46 As the first and second digit. Series type code for general industrial seals.
56 As the first and second digit. Series type code for Universal Cartridge Seals ™.
1 As the third digit, defines the assembly arrangement. Single seal.
2 As the third digit, defines the assembly arrangement. Dual seal, double or tandem.
0 As the fourth digit, defines the version of secondary seal. Pusher type, dynamic o-ring.
1 As the fourth digit, defines the version of secondary seal. Non-pusher type, elastomeric bellows.
5 As the fourth digit, defines the version of secondary seal. Non-pusher type, welded metal bellows.
Q As the suffix symbol. Indicates a quench type of gland plate.
PR As the suffix symbol. Indicates that a pumping ring is included with a dual seal arrangement.
Seal Identification 11
Table 1 - Seal Head and Series Numerical Designations
SECONDARY SEAL
FAMILY PREFERRED SEAL TYPES RETIRED SEAL TYPES
1 2 11 22A 5611 1A 1M
Non-Pusher 1B 2B 11A 25 5611Q 1ESP 2M
Elastomeric Bellows 1DBL 6 21 25A 43 1100
1102 6A 21B 2100 502
15 15WG 315RS
604 1604 3635
15W 15WTG 715
Non-Pusher 604J 1635
15WT 15WLG 1715
Metal Bellows & 605 2609
15WTL 15WTLG 1615
Compression Ring 606 2635
15WLRS 15WLU
609 2715
15WTLRS 15WLGU
609J 3609
15WRS 315
15WTRS 315H
5625 675 1670 ECS 15WO 515E 623
5625PR 676 2670 GLIB 15WTO 515K 632
Non-Pusher 5615 613 680 3670 15WTOESP 1115 633
Metal Bellows & 5615Q 670 EZ-1 285 15WORS 1215 642
O-Ring 2800MB 1625 2625 3625 15WTORS 2115 643
115 2215 515C
115G 5515 1515Z
115SRS ECS
215 611
215G 622
Non-Pusher 10R 20 20S 20S Dbl 659
PTFE Bellows 10T 20R 20R-S 650
Non-Pusher 37FSB 27
Compression Ring 37FS
12 Seal Identification
SECONDARY SEAL
FAMILY ACTIVE SEAL TYPES RETIRED SEAL TYPES
28 32 S48 32FS
28SC 32GL 75FS 8000
28AT 33P 7700 1010
Pusher 28BD 33PB 1648 1011
O-Ring 28LD 36 2648 1012
Specialty 28ST 38B 3648 28MD
28VL 38BRS 3710 28NE
28XP 48HP 285 28P
2800 48LP RREP
2800E 48MP RRAL
2800HP 48SC RREL
2800SS 48RP SBOP
2800EX 208BHB
Seal Identification 13
Figure 2 - Common Cross Section Examples
Non-Pusher
Elastomeric Bellows
Type 1 Type 21
Non-Pusher
Metal Bellows &
Compression Ring
Type 606 Type 609
Non-Pusher
Metal Bellows &
O-Ring
Type 680
Non-Pusher
PTFE Bellows
Non-Pusher
Compression Ring
(Faces Identical)
Type 37FS
Pusher
O-Ring
Pusher
Wedge
Type 9
14 Seal Identification
John Crane Mating Rings
Mating rings and their appropriate gaskets are not designated by a number or letter. They are commonly
referred to by a word describing their cross-sectional shape, mounting method, or equipment fit. Many mating
ring designs could be used with numerous seal head designs. They are typically not included in a specific
seal head designation, but are often described following a seal head designation. All mating rings have a size
designation that is their inner diameter size. There are three groups of mating rings: standard, specific, and
special.
Standard Design
Standard designs are intended for use with any standard seal head assembly. The standard designs are:
o-ring, square, cup mount, floating, and clamped. Standard designs are available in a wide variety of sizes,
starting at 1/2” through 8” of inner diameter. They are available in several standard materials such as cast
iron, ni-resist, alumina, tungsten carbide, and silicon carbide.
! O-ring type mating rings are sealed by an o-ring within a groove on the outer diameter. In most cases
o-ring compression prevents rotation.
! O-ring pinned type mating rings have a pin slot on the non-lapped side and are not reversible.
Perfluoroelastomer o-rings require pinned mating rings. Pin slots are now standard on John Crane
o-ring type mating rings.
! Square type mating rings are sealed by an o-ring within the gland plate. A chamfer is cut on the ring
outer diameter back side to prevent o-ring damage during installation. They are reversible if the rear
side has been lapped with a chamfer cut on the outer diameter of the original lapped side. In most
cases o-ring compression prevents rotation.
! Square pinned type mating rings have a pin slot on the non-lapped side and are not reversible.
Perfluoroelastomer o-rings require pinned mating rings. Pin slots are now standard on John Crane
square mating rings.
! Cup mount type mating rings are sealed by an elastomeric “L” shaped gasket that appears as a cup
after molding. The ring has a chamfer cut on the outer diameter back side. Gasket compression
prevents rotation.
! Floating type mating rings are sealed by a rectangular PTFE ring. A chamfer is cut on the PTFE ring
outer diameter back side for installation purposes. The PTFE ring back side will be marked with red
grease pencil and the mating ring is pinned to prevent rotation. In temperature extreme service,
the gasket is constructed of a graphite material. When elastomers are used as the gasket
material, the gasket compression prevents rotation.
! On clamped type mating rings the length of the “shoulders” is equal to the amount of compression
on the seal head. When the gland plate is tightened the shoulder is inserted into the seal chamber
to compress the seal head. The mating ring may be reversed if the rear side has been lapped. Two
flat gaskets are supplied with the mating ring. One gasket fits on each shoulder. In most instances
one gasket is PTFE and one is fiber. The PTFE gasket is positioned on the shoulder sealing the
pumped fluid.
Seal Identification 15
! Modified clamped type mating rings have one shoulder eliminated from the mating ring for economy.
They are not reversible. The length of the single “shoulder” is equal to the amount of compression
on the seal head. When the gland plate is tightened the “shoulder’ is inserted into the seal chamber
to compress the seal head. Two flat gaskets are supplied with the mating ring and are located on
each side. Gasket compression and proper gland tightening prevent mating ring rotation.
! Modified clamped donut type mating rings have both shoulders removed for economy. The mating
ring may be reversed if the rear side has been lapped. Two flat gaskets are supplied with the mating
ring and are located on each side. Gasket compression and proper gland tightening prevent mating
ring rotation.
With Gasket With V-Ring With O-Ring With O-Ring With Gasket
Clamped-In Design
Specific Design
Specific designs are intended for use with a specific seal head or in cartridge assemblies. Specific designs
are only available in limited sizes. These are the commonly used sizes that are in 1/8” or 1/4” increments.
Materials are typically limited to those that have a wide range of application capability such as tungsten
carbide or silicon carbide. Universal “L” type mating rings are found in several different cartridge seal
assemblies. They are installed in the gland plate or adapted to the cartridge sleeve. They are sealed with an
o-ring and secured with two pins 180° apart to prevent independent rotation. This type of mating ring is easily
installed with hand pressure, an audible click is heard when it is seated properly.
Special Design
Special designs are manufactured according to equipment specifications for unique equipment. These are
usually designs engineered by the original equipment manufacturer. There are several specially designed
mating rings. They are often referred to by the name of the original equipment manufacturer. Special design
mating rings are usually only manufactured in one size and one material.
16 Seal Identification
Figure 4 - Specific Mating Ring Designs
Seal Identification 17
Seal Assembly Size
The size of the seal is expressed as either a whole and fraction number or whole and decimal number.
Example: 3 7/8” or 3.875”
For independent seal heads, the size is the inner diameter of the seal head where it is affixed to the shaft or
sleeve. The inner diameter of the primary ring is not used because it may have a smaller inner diameter as a
result of hydraulic balancing. Independent mating rings will be sized according to their inner diameter.
Sleeves are sized by their inner diameter. Since a cartridge seal is pre-assembled onto a sleeve, the
cartridge size is according to the inner diameter of the sleeve. The cartridge size designation will in most
cases be the pump shaft size. If the pump uses a shaft sleeve, the cartridge size designation will be the
pump sleeve size. The seal size is an independent designation. It is not included in the seal type or material
codes.
John Crane Sealol seal types use a two digit numerical code trailing the part number as drawing number.
That number, divided by 16, yields the size in decimal inches. Example:
609XCC-FCP307-28
28/16 = 1.750”
18 Seal Identification
John Crane Material Codes
The John Crane system of identifying the materials of construction uses a seven position symbol code that is
in a sequential order. Each symbol identifies a component or group of components in the seal assembly. The
codes are alphabetical letters, numbers, or alphanumeric combinations. The material codes only identify
materials, the seal design, size, or drawing is not included in the code. The component design is not
described by the code. A chart of component designs by material code symbol position is shown on page 22.
The material codes are found on bills of materials, seal layout drawings, and seal box labels. Because a
material code explains an immense amount of information in a small space, it is used in many engineering
documents. Most notably it is used on application charts (D-SK charts) to explain a recommended set of
materials for a specific fluid and operating conditions. The seven position symbol code replaces a five
position system, see Addendum 6, page 75.
A letter, number, or alphanumeric combination symbol has a description that explains all of the material data.
A four digit number will also be assigned to that symbol. This is another means of expressing the specific
material. The four digit number is attached to end of a component detail drawing number to form a total part
number.
The material code is often referred to as the “BRICI” code. It was developed several years ago before the use
of computers and word processors when the equipment used for word processing was a typewriter. The
symbols for the material code are the letters, numbers, and marks found on a typewriter. The initial codes
were very simple, involving just letters or numbers. With seal technology advancements the material codes
became more complex. Additional numbers were added to existing codes. Other marks found on the
typewriter keyboard were added to the system and are referred to as special notations. Because a word
processor keyboard is essentially the same as a typewriter keyboard the material code system continues with
very little modification. The special notations are explained below.
Examples:
F51 - A specific grade of carbon further identified by the subscript of number 51.
O58 - A special material further identified by the subscript of number 58.
X51 - A specific Isolast ™ perfluoroelastomer further identified by the subscript of number 51.
Parentheses
If the second or fifth symbol is contained in parentheses the primary ring (second symbol) or mating ring (fifth
symbol) is coated. The symbol denotes the base material. Coatings are rarely used.
Example:
BF511B(5)1 - Indicates that the mating ring (fifth symbol) is coated.
Seal Identification 19
Seal Identification
Figure 6 - John Crane Material Codes
John Crane seal codes designate the materials used to manufacture a seal. The sequential order of the code numbers and letters has a specific
meaning. A detailed explanation of the codes is provided in Addendum 7.
1ST SYMBOL 2ND SYMBOL 3RD SYMBOL 4TH SYMBOL 5TH SYMBOL 6TH SYMBOL 7TH SYMBOL
Q F51 C
1 B F50 7
20
Slash Line
The slash line is used in the seventh symbol position. It is used to separate the materials of the hardware
(third symbol) and loading device (sixth symbol). The code to the left of the slash designates the material for
the hardware. The code to the right of the slash designates the material for the loading device.
Example:
XF311XCH 316/HC - Indicates 316 stainless steel hardware and a Hastelloy C loading device (spring).
Dash
A dash line used in any symbol position indicates the absence of the specific component. The component is
either not necessary or is not supplied by John Crane.
Examples:
1F71O95- The dash in the sixth symbol indicates that a spring is not necessary in the assembly.
BF511--1 The dashes in the fourth and fifth symbol indicate that the mating ring and its secondary seal
are not supplied.
Example:
QF51HQCH (Inboard) XP901X71 (Outboard)
Notes:
Do not randomly modify the system to meet the needs at hand. All of the symbols used have a specific
meaning. To incorrectly use a symbol may change the meaning of the entire code. The Following are
examples of commonly used corrupt codes.
Examples:
XF(51)1XD1 - This is an incorrect use of parentheses to note a subscript number.
XP/661XC1 - This is an incorrect use of the slash line to note a subscript number.
XO-58HX0-58H - This is an incorrect use of the dash line to note a subscript number.
Miscellaneous
Modifications to the code system are often required as a result of the means used for printing the code. Some
systems may only allow a limited number of digits. Some systems may not permit the use of subscript
numbers. In this case blank spaces are often used to separate the five symbols.
Seal Identification 21
Figure 7 - Pictorial Description of a Seven Digit John Crane Material Code
Seal Identification
1ST SYMBOL 2ND SYMBOL 3RD SYMBOL 4TH SYMBOL 5TH SYMBOL 6TH SYMBOL 7TH SYMBOL
Secondary Primary Hardware: Secondary Mating Loading Metallurgy
Seal for Ring Retainer, Seal for Ring Force 3rd / 6th
Primary Ring Disc, Etc. Mating Ring
Bellows Types 1 & 2 Types 1, 2, & 21 Types 1, 2, & 21 Gaskets, O-Rings, Pinned O-Ring Multiple Coil Spring
O-Ring Types 8 & 48 Type 8 Types 8 & 9 Rectangular O-Ring Single Coil Spring
Clamped-In
Compression Ring 600 Series
Type 37 Metal Bellows
Modified Clamped-In
PTFE Bellows
Type 20
Metal Bellows
Wedge O-Ring Grafoil
Note: Seal adaptive hardware including glands, sleeves, collars,
pins, screws, etc. are not described by this code.
22
Material Codes, Part Number Suffix, and Descriptions
Table 2 is a list of three columns. The left column is the material code. The center column is the four digit
material code commonly used as a part number suffix. The right column is the material description. The most
commonly used codes are listed. Those codes that are infrequently used are not listed. The list will note
codes that have been made obsolete or have been superseded by an improved technology. Obsolete codes
remain on the list because of existing inventories and documentation. The list for families of carbon has been
expanded and follows the general list in Table 4, page 28.
Seal Identification 23
Material Part Number
Code Suffix Description
24 Seal Identification
Material Part Number
Code Suffix Description
Seal Identification 25
Material Part Number
Code Suffix Description
26 Seal Identification
Material Part Number
Code Suffix Description
Seal Identification 27
Carbon Families
The John Crane Engineering Department has many grades of carbon available for use. Because of the many
advantageous qualities of carbon, it is the most widely used material for primary rings. Carbons are
designated as either a specific or as a family. A specific carbon grade is one that is of an individual
composition and performs satisfactorily in a service. A family of carbons is a group of specific carbon grades
that all have similar compositions and perform satisfactorily in a service. Specific carbon grades that have no
equivalent will remain independent and are not included in a family. Specific carbon grades are designated
by the code letter P and are usually followed by a subscript number. Families of carbon grades are
designated by the code letter F and are usually followed by a subscript number. Several years ago the letter
R was used to designate carbon, however the use of R has been discontinued. Common carbon families are:
F5 N905 Nuclear water carbon Radiation resistant Radioactive & borated water
F10 9010* Hot water carbon Metal filled Hot & cold water on
(180°F / 82°C operating) bulletin 35-36 S, 350°F / 175°C
maximum
F11 9011* Hot water carbon Metal filled Hot & cold water on
(180°F / 82°C operating) bulletin 35-36 S, 700°F / 370°C
maximum
F12 9012 Hot water carbon High temperature & Hot water
(300°F / 150°C operating) chromate abrasive
resistant
F20 9020* High strength carbon Metal filled Pipelines & petroleum plants
F25 9025* Blister (pock) resistant Self venting Thick oils & other viscous
carbon liquids
F26 9026 Blister inducing service Blister resistant Oils & refrigeration
28 Seal Identification
Family Suffix Generic
Code Code Name Feature Common Use
F35 9035* Refrigerant service Blister resistant Cold oil & refrigerants: i.e.
carbon ammonia, LPG & freon
F40 9040* Air conditioning Moldable for high Oil mixed with refrigerants
compressor carbon volume
F41 9041* Very light duty - Moldable Appliances & auto coolants
carbon & phenolics
F50 9050 Super carbon for High corrosion & General service except
general service abrasion resistant extreme corrosion
F51 9051 Super carbon for High corrosion & General service except
general service abrasion resistant extreme corrosion
Seal Identification 29
Materials
John Crane uses a wide variety of materials in the construction of mechanical seal assemblies. Secondary
seals are made of elastomers, fluoropolymers, metals, synthetic fibers, and vegetable fibers. Primary rings
are most often made of a carbon variant or ceramic material. Mating rings are made of metals and ceramics.
The hardware and springs for the assembly are made of metals. Table 5 below lists the basic materials for a
component category. In the table the number in parenthesis represents the number of compound variations
that are available for use in a seal assembly. A brief description of the seal materials that are commonly used
follows on pages 32 - 42.
30 Seal Identification
Selection Considerations
Each seal assembly component must be compatible with several application factors. Materials are selected
after laboratory tests and engineering calculations. Several considerations are weighed when selecting a
material. These considerations are shown in Table 6 below.
Seal Identification 31
Carbon Graphite
Elemental carbon is number six on the Periodic Table. It exists with three different crystal structures.
Diamond is carbon with a three equal dimensional crystal structure. Graphite is carbon with a layered crystal
structure, similar to sheets in a ream of paper. Coke, lampblack, and charcoal are carbon with a chain crystal
structure that resembles tangled ropes. It is the layered crystal structure of graphite that makes it slippery. It
is the tangled rope like crystal structure of coke and lampblack that make them hard and wear resistant.
Graphite powder is like ground coal. Coke is made from crude oil. Lampblack is made by heating a
hydrocarbon gas, such as methane, in the absence of air.
Mechanical Carbon
Mechanical carbon is made by mixing graphite powder, coke powder, and lampblack powder with coal tar
pitch at approximately 500°F / 275°C. Coal tar pitch is the same material that is melted and then spread on
flat roofs to seal cracks. After mixing the powders and pitch, the material is cooled and then milled into a fine
powder. That fine powder can then be compaction molded to form rings. For mechanical seals the powder is
primarily molded into ring shapes, it can be molded into other shapes for other applications. The powders are
held together by a physical, mechanical action rather than a chemical action. After molding, the rings are
baked to approximately 2000°F / 1095°C in a non-oxidizing atmosphere. During the baking process the coal
tar pitch is changed to carbon. This chemical change causes the coal tar pitch to shrink. The shrinkage of the
coal tar pitch leaves the carbon ring with about 15% porosity. The pores may be filled with another material in
a manufacturing process or in a service. After baking the ring material is called carbon-graphite. The graphite
content makes the material slippery or self lubricating. The coke and the lampblack content makes the ring
material hard and wear resistant.
Carbon-graphite is used as a primary ring material in many seal applications. Many general service grades of
carbon-graphite can be used in services up to 500°F / 275°C. Specialty grades permit operating
temperatures of 500-1000°F / 275 - 535°C. In service it is flexible, capable of handling distortions due to
operational or mechanical upsets. Carbon-graphite is a proven material in high pressure applications. It is a
common material used in boiler feed water applications where the seal chamber pressure may be up to 2000
psi / 138 bar. Carbon-graphite is very resistant to chemical attack. It is one of the most chemically inert
materials available for primary rings. It is recommended in many solvent, acid, and caustic services. It is
easily manufactured at a competitive cost.
Metallized Carbon
Metallized carbon, metal impregnated carbon, and metal infiltrated carbon are three different terms for the
same material. To make metal impregnated carbon, mechanical carbon-graphite is submerged in molten
metal. High pressure gas is used to force the molten metal into the pores of the carbon-graphite material.
High pressure is used to assure that the metal is forced completely through the carbon-graphite so that all of
the pores are completely filled with metal. After impregnation the metal content is normally between 20% and
35% by weight. The percentage is dependent upon the metal used and the porosity of the base carbon-
graphite.
Many metals are used to impregnate carbon-graphite. The metals most commonly used are bronze, copper,
silver, antimony, nickel-chrome, and babbitt. Babbitt is an alloy usually containing tin, copper, and antimony.
Impregnation with these metals enhances the properties of the mechanical carbon-graphite material. After
impregnation, carbon-graphite is stronger and more pressure tight. It is less susceptible to distortion in high
pressure applications. It has improved lubricating qualities. Metal impregnation increases thermal
conductivity, which enables the material to better conduct frictional heat away.
32 Seal Identification
Ceramics
There is some confusion about the term ceramic. Ceramic is a class of materials made at high temperature to
form an oxide, nitride or carbide. This process is known as sintering, and the material is heated until it
becomes a mass without melting.
Carbides
Carbide is a binary solid compound of carbon and another element. Other elements can include boron,
silicon, and tungsten. Mechanical seal faces are usually a combination with boron, silicon, or tungsten.
Carbides are characterized by great hardness, thermal stability, high melting point, and chemical resistance.
Because of its resistance to heat, carbide is referred to as refractory. Cemented carbide is the combining of a
powdered form of refractory carbide with a bonding material under compression, then sintering. The bonding
material for tungsten carbide seal faces is either cobalt or nickel. Sintering occurs at temperatures above
2600°F / 1425°C, dependent upon the bonding material.
Silicon carbide is one of the hardest materials known, only boron carbide and diamond are harder. This
extreme hardness gives silicon carbide excellent wear resistance in both clean and abrasive applications.
Silicon carbide has a high specific strength (strength to density ratio) which makes it excellent for high speed
applications. It has a high modulus of elasticity which gives it good face stability in high pressure applications.
The only common disadvantage of silicon carbide is that it is not as tough as other materials in fracture
resistance. For mechanical seals, that is an insignificant disadvantage.
Silicon carbide is an excellent conductor of heat. This high thermal conductivity coupled with a low coefficient
of expansion gives it a high resistance to thermal shock. This also gives it excellent thermal stability over a
wide temperature range. For mechanical seal faces, this results in its ability to retain face flatness in service.
The single phase sintered silicon carbide has proven excellent corrosion resistance. It is not chemically
attacked in reducing and oxidizing environments. It is resistant to galvanic corrosion. The two phase reaction
Seal Identification 33
bonded silicon carbide is very chemically resistant, however strong oxidizing reagents like sodium hydroxide,
oleum, and hydrofluoric acid attack the free silicon metal content. Therefore, the single phase sintered is
considered to be more chemically resistant than the two phase reaction bonded silicon carbide. Sintered
silicon carbide is the standard material used by John Crane Inc. Reaction bonded silicon carbide is available
on an as needed basis.
Silicon carbide is commonly used as both a primary ring and a mating ring material. A variety of face
combinations can be involved. Sintered silicon carbide primary rings are used against tungsten carbide or
sintered silicon carbide mating rings. Reaction bonded and graphite primary rings are used against tungsten
carbide or sintered silicon carbide. In most arrangements the mating rings will have a lapped and polished
finish. Some primary rings of selected grades of silicon carbide will also have a lapped and polished finish.
However, most primary rings of silicon carbide will have a lapped and matte finish. Recently a number of new
versions of silicon carbide have been introduced.
The only materials harder than tungsten carbide are boron carbide, silicon carbide, and diamond. Its
hardness makes it a very good material in clean and abrasive services. It has good ratings for specific
strength, which limits its capabilities in high speed applications. It has a high modulus of elasticity which
makes it strong in high pressure applications. It has good ratings for fracture resistance, and is superior to
silicon carbide in that characteristic.
Tungsten carbide has excellent ratings for thermal conductivity. It has a low coefficient of thermal expansion,
and good ratings for thermal stability. These characteristics make it a good material for temperature extreme
services.
Tungsten carbide has excellent corrosion resistance in hydrocarbons, solvents, acids, and alcohols up to
800°F / 427°C. Cobalt bound tungsten carbide has performed well in ammoniacal solutions. The nickel bound
tungsten carbide is superior in aqueous solutions.
A variety of seal face material combinations involving tungsten carbide have proven excellent performers.
Tungsten carbide is used primarily as a mating ring material. It has also been used as a primary ring material.
When using the combination of a tungsten carbide primary ring against a tungsten carbide mating ring, the
mating ring will have a lapped and polished finish, the primary ring will have a lapped and matte finish.
Primary rings of silicon carbide will have a matte finish when used against tungsten carbide. Primary rings of
carbon will have a lapped and polished finish when used with tungsten carbide mating rings.
34 Seal Identification
Elastomeric Compounds
The vast majority of mechanical seals produced by John Crane use an elastomer for secondary seals in both
static and dynamic conditions. An elastomer is a material, natural or synthetic, exhibiting little plastic flow and
a quick or nearly complete recovery when stretched. Essentially, the ASTM requirements for an elastomer
are:
Compounds are mixtures of base polymers and other chemicals to form an elastomer material. There may be
several variations of a basic compound. A basic polymer may be blended with various percentages of
reinforcing, curing, vulcanizing agents, and other materials to form a compound with distinct properties. The
following are the general elastomeric compounds most commonly used as secondary seals: o-rings, bellows,
compression rings, and gaskets. The generic name for the elastomer is listed, the common trade name and
national ASTM letter designation is in parentheses.
Seal Identification 35
harden and shatter in ammonia. It has replaced Polyacrylate in most applications. Temperature range -20 to
+400°F / -29 to +204°C. Specific Gravity: 1.85.
Fluorosilicone (FSi, FVMQ)
Fluorosilicone has good temperature critical application capabilities. It has good resistance in hydrocarbon
service at high and low temperatures. Caution should be taken as some fluids at 350°F / 177°C produce
acids that will attack fluorosilicone. Temperature range -100 to +350°F / -62 to +177°C. Specific Gravity: 1.40.
36 Seal Identification
requiring such resistance. John Crane uses it in Super Seal packings and various coatings and impregnants.
It also used in sheet packings. Temperature range -65 to +200°F / -54 to +93°C. Specific Gravity: 0.93.
Tetrafluoroethylene Perfluoroelastomer (Chemraz™, FFKM)
This elastomer is selectively used in acids, alkalies, ketones, esters, aldehydes, alcohols, and fuels. It is
particularly noted for resistance in steam and hot water service. This material offers the resiliency of an
elastomer combined with the chemical resistance of polytetrafluoroethylene. Temperature range -50 to
+500°F / -46 to +260°C. Specific Gravity: 2.0.
Fluoropolymer Compounds
Polytetrafluoroethylene (Teflon™, Chemlon™, PTFE)
Polytetrafluoroethylene has an extremely low coefficient of friction. PTFE is commonly molded, extruded and
machined into mechanical seal components such as wedges, v-rings, u-cups, gaskets, and bellows. It is also
used as a material for packings, bearings, piping, insulators, valve seats, piston rings, tube protectors and
lantern rings. It has almost an unlimited capacity as a component material. PTFE is commonly used in acids,
alkalies, ketone, esters, alcohols and hydrocarbons. It is operable in a pH range of 0-14. PTFE should not be
used in chlorine trifluoride, fluorine, and molten alkali metals. PTFE does not stick to anything. It deteriorates
with age and it can cold flow with pressure extremes. Temperature range -75 to +250°F / -60 to +121°C in
most services, however the range is expanded to 450 to 500°F / 232 to 260°C in selected services. Specific
Gravity: 2.25.
Bronze Black
Calcium Fluoride Yellow
Carbon Stainless Steel Red
Glass Fiber Green
Graphite Orange
Moly Disulfide Blue
Stainless Steel
Seal Identification 37
addition of a color. The operating temperature range and specific gravity varies by the mixture. The list below
notes the basic material combinations and colors.
Metals
Cast Iron
Cast iron is a generic term for a group of metals that are basically alloys of iron, carbon, and silicon. Relative
to steel, cast iron contains high amounts of carbon and silicon. The approximate composition of cast iron is
.5-4% carbon, .2-3.5% silicon, and 92% iron. Iron naturally contains small amounts of other materials. Cast
irons may contain small amounts of other materials that are added to modify their properties. It used in mild
to neutral pH ranges. For mechanical seals, it is used primarily as a mating ring material in cool, clean
applications. It can be manufactured at a low cost and has an economic advantage over other materials. It is
not magnetic. It is used in temperatures to 350°F / 177°C.
Ni-Resist
Ni-Resist is either a cast ductile iron with nickel or a nodular austenitic iron with nickel. It has proven to be a
capable material in water services. It has only fair ratings for resistance to weak and strong acids or alkalies.
It can be manufactured at a low cost and has an economic advantage over other materials. For mechanical
seals, it is used primarily as a mating ring material. It has been used in limited applications as a primary ring
material. It is not magnetic. It has a maximum temperature capability of 350°F / 177°C.
Naval Bronze
Naval Bronze is an improved Muntz metal similar to brass which was developed to be more corrosion
resistant than brass. Slightly different proportions of copper and zinc plus a small amount of tin has given it
these qualities. It is comprised of 60-65% copper, 34-39% zinc, and .5-1% tin. Naval Bronze is often called
Naval Brass. This alloy is named for its ability to survive the corrosive environment of salt water. It is used
primarily in marine applications. It has good wear and strength qualities. Maximum temperature 350°F /
177°C.
Hastelloy™
Hastelloy Alloy C is a nickel, molybdenum, and chromium wrought alloy. Alloy C-276 is an improved wrought
version of Alloy C. Alloy C-276 does not need to be heat treated after welding. It has improved machining
characteristics. This alloy resists the formation of grain-boundary precipitates in the weld heat-affected zone,
thus making it suitable for most chemical process applications. Alloy C-276 has outstanding resistance to
localized corrosion. Because of its versatility, Alloy C-276 can be used where “upset” conditions are likely to
38 Seal Identification
occur or in multipurpose processes. It has exceptional resistance to a wide variety of chemical processes
including strong oxidizers, chlorides, formic and acetic acids, acetic anhydride, and seawater and brine
solutions. It has excellent resistance to sulfur compounds and chloride ions. Alloy C-276 has excellent
resistance to pitting, stress-corrosion cracking, and to oxidizing atmospheres. It is also one of the few
materials that withstands the corrosive effects of wet chlorine gas, hypochlorite, and chlorine dioxide.
Hastelloy is used for metal bellows seal types and as seal hardware. Hastelloy is recommended for
applications with temperatures over 400°F / 204°C.
Inconel™
Inconel is comprised of approximately 76% nickel, 17% chromium, and 7% iron. Its most exceptional
capability is temperature resistance. It is used in applications with temperatures over 400°F / 204°C. It is
often used in metal bellows seal type assemblies. Inconel 600, 718, and X750 are excellent for use in
corrosive environments at elevated temperatures. Inconel Alloy 600 is a high nickel alloy that is hard, strong,
and corrosion resistant. It is often used as the end fittings in a metal bellows assembly. Inconel 718 and X750
are used as the plate material for metal bellows assemblies. Inconel 718 is the highest strength bellows
material and it has good resistance to stress corrosion cracking. Inconel is also used in tanks, valves, coils,
heat exchangers, and piping. It is often recommended in applications with wide temperature fluctuations.
Monel™
Monel Alloy 400 and Alloy K-500 are nickel - copper alloys with distinguishing characteristics of strength,
hardness, and corrosion resistance for special applications. Because of its low iron content, Monel is an
exceptional material in pH extreme conditions. Monel Alloy 400 is approximately 67% nickel, 30% copper;
and 3% iron. Monel Alloy K-500 is similar except that it has about 3% aluminum instead of iron. The magnetic
structure of Monel Alloy 400 changes based on temperature conditions. Monel Alloy 400 and Alloy K-500 are
both rated for applications up to 400°F / 204°C. Monel is used in several seal types in assembly components.
It is recommended for hydrofluoric acid applications. Its corrosion resistance lends itself to many marine
applications.
Stainless Steels
Stainless steels are broadly defined as iron alloys containing from 10 to 30% Chromium and from 0 to 20%
nickel. This analysis is further modified by additions of carbon and other minor elements which contribute
specific effects either to control mechanical properties or to improve corrosion resistance. The corrosion
resistance of stainless steels is attributed to a surface phenomenon, passivity. When oxygen comes in
contact with the surface, it forms an invisible film of chromium oxide which protects the underlying metal from
rusting and corrosion in severe environments.
Due to differences in characteristics, stainless steels are divided into three general classifications: Austenitic,
Martensitic, and Ferritic. Austenitic stainless steels make up the general group of the 18-8 (or 300) series.
They are the chromium-nickel type containing more than 8% nickel. They can not be hardened by heat
treatment. They are non-magnetic for practical purposes. The Austenitic stainless steels offer the greatest
degree of corrosion resistance. The Martensitic stainless steels contain 12 to 20% chromium. They are
magnetic and can be hardened by heat treatment. Type 410 and 416 are Martensitic stainless steels. The
Ferritic stainless steels contain chromium. They are magnetic, however they can not be hardened by heat
treatment. Type 430 is an example of Ferritic stainless steel.
Because of its high tensile strength and corrosion resistant qualities stainless steel is one of the most
versatile of all metals. Stainless steel can also be polished to a mirror-like finish. Applications include its use
Seal Identification 39
in chemical, food, petroleum, pharmaceutical, pulp and paper, transportation, water, and wastewater
equipment and markets. The list below includes the various types of stainless steel alloys which are most
frequently used in the manufacture of mechanical seal components, such as: retainers, discs, springs, and
set screws.
17-4PH™
17-4PH is a precipitation hardening stainless steel that is used for many industrial applications. It is often
used for metal bellows seal types. Extensive manufacturing and heat treating techniques provide 17-4PH
products in a variety of capabilities. These capabilities offer a combination of high strength, hardness, anti-
galling, and corrosion resistance characteristics. 17-4PH is currently being used in many corrosive
environments at elevated temperatures in the chemical, and petroleum industries.
Alloy 20
Alloy 20 stainless steel was developed to improve resistance to corrosion by sulfuric acid. It exhibits superior
resistance to stress-corrosion cracking in boiling 20-40% sulfuric acid. It is widely used in many phases of
chemical processes. It has been used extensively in the processing of synthetic rubber, high-octane gasoline,
solvents, explosives, plastics, synthetic fibers, heavy chemicals, organic chemicals, pharmaceuticals, and
agricultural chemicals. It is used where purity must be maintained in the processing of products such as food
and pharmaceuticals. Alloy 20 stainless steel has been used to protect the end products from the danger of
metallic contamination. Alloy 20 stainless steel has been applied economically where other materials may
provide the necessary corrosion resistance, but are initially more expensive. Important advantages for Alloy
20 stainless steel are its excellent mechanical properties and ease of fabrication. Alloy 20 stainless steel has
been used in seals, fans, mixing tanks, agitators, distillation towers, heat exchangers, process piping,
cleaning and pickling tanks, pickling equipment, pump shafts, rods, valve stems, and fasteners. Alloy 20 is
used in seal applications requiring greater corrosion resistance than either 304 or 316 stainless steel. The
Type 680 seal uses Alloy 20 for all of its components.
Type AM350
Type AM350 stainless steel is a heat treatable stainless steel that has corrosion resistance similar to type
304 stainless steel. It is the most commonly used stainless steel for metal bellows applications. Type AM350
is a high strength stainless steel with three times the strength of either Alloy 20 or Hastelloy.
Type 302
A general purpose 18-8 grade chromium-nickel stainless steel. It has a ratio of 17-19% chromium and 8-10%
nickel. It retains an untarnished surface under most atmospheric conditions and offers high strength at
reasonably elevated temperatures.
Type 303
A free machining chromium-nickel stainless steel with qualities similar to Type 302. Elements have been
added to improve its machining characteristics. It only used in the mild to neutral pH ranges because it has
only fair resistance to corrosives.
Type 304
A general purpose 18-8 grade chromium-nickel stainless steel. It has a ratio of 18-20% chromium and 8-12%
nickel. It is superior to Type 302 in corrosion resistance.
Type 310
A chromium-nickel stainless steel with a ratio of 24-26% chromium and 19-22% nickel. It offers the highest
40 Seal Identification
heat resisting qualities of any of the chromium-nickel grades.
Type 316
A chromium-nickel stainless steel with a ratio of 16-18% chromium and 10-14% nickel. It differs from 304
mainly by its molybdenum content and has qualities which give it superior corrosion resistance to other
chromium-nickel steels. It is particularly effective when exposed to sea water and many types of chemical
atmospheres. It is also a superior stainless steel for strength at elevated temperatures.
Type 410
A general purpose stainless steel. It contains 11.5-13.5% chromium. It does not contain nickel. It is used in a
mild to neutral range of pH. It has mild corrosion and heat resistance. It can be hardened by heat treatment. It
has fair machining properties.
Type 416
Similar to type 410 but has slightly more chromium and is considered a better machining grade than Type
410. It contains 12-14% chromium. It can be hardened by heat treatment.
Type 430
Similar to Type 410 but containing additional chromium of 14-18%. It is can not be hardened by heat
treatment. The corrosion and heat resistance qualities are generally superior to Type 410.
Non-Ferrous Alloys
Titanium
Titanium is lightweight, strong and highly resistant to corrosion. Titanium alloys are comprised of 85%
titanium and 15% of several other materials. For a material that weighs only 60% of steel, it has excellent
strength. Its corrosion resistance is superior to that of stainless steel. It performs excellently in salt water
service. Being a non-ferrous alloy, titanium is non-magnetic. It is particularly resistant to chlorine chemicals
and the chlorites: hypochlorite, perchlorate, and chlorine dioxide. Titanium also exhibits good resistance to
nitric, chromic, hydrochloric, and sulphuric acids. It offers good resistance to organic chemicals. Titanium’s
corrosion resistance is due to its ability to form a protective oxide film upon exposure to air and most other
oxidizing media. If this film is damaged, it tends to reform immediately. Titanium is resistant to environments
which will maintain this oxide film; conversely, it is attacked by those which will break it down. It performs well
in neutral and oxidizing media and reducing solutions containing oxidizing ions or inhibitors. Titanium is the
material of choice in such heavily corrosive areas as aluminum anodizing, chemical processing, medical
products, and marine applications. It is used in many seal types in assembly components. Commercially pure
Titanium CP Grade 2 is used in metal bellows assemblies. It is often used as a material for pumps. Titanium
performs well at high temperatures.
Seal Identification 41
Miscellaneous Materials
Boron Carbide (B4C)
Boron carbide is equal to silicon carbide in specific strength and modulus of elasticity. It has lower
coefficients of thermal expansion and conductivity than silicon carbide. It is virtually inert to most hot
chemicals over a wide range of temperatures. It has proven an excellent material in higher concentrated
acids. It is oxidation and reduction resistance that is rated over 2000°F / 1093°C. The disadvantage of boron
carbide is its material and manufacturing costs. While the performance of boron carbide is good, it does not
perform significantly better than silicon carbide. Therefore, it has seen limited use as a mating ring material
for mechanical seals and is not a standard material.
Natural graphite has an inherent lubricity because of its crystalline structure. The very thin flat crystals are
like plates and are arranged in a regular pattern. That plate structure allows for easy sliding on each other.
Because of its plate structure and low coefficient of friction, it is classified as a solid lubricant. Flexible
graphite is superior to most other materials for thermal conductivity. Heat from the operating process or
friction is rapidly moved away from the heat source. Its operational temperature range is from -400 to
+ 700 °F / -240 to 371°C. It has little thermal expansion. Flexible graphite can operate in a pH range of 0-14.
In radioactive service, its resistance qualities are as high as 5.5 x 1021 NVT at 1857 °F / 1014°C neutron
dosage and 1.5 x 1011 ergs/gram Gamma radiation. This means that radiation has no apparent effect on
flexible graphite. Being flexible, it easily moves into voids, pits, scratches, and irregularities on the surface it
is applied to with no plastic flow from high pressures.
There are few design restrictions on flexible graphite and it can be manufactured into several forms. It can be
made into large sheets and then cut into flat gasket shapes. Wire may be added to add strength. Sheets may
be stacked and pressed together to form a laminated sheet which may then be used as a gasket material. It
is often supplied in a ribbon form which then can be used as a gasket. Ribbon form may rolled and die-
formed into a ring.
In mechanical seal assemblies, it is used as a gasket to seal gland plates. It is used as a wide gasket to seal
mating rings in position. Most often it is used a gasket to seal a metal bellows assembly to the shaft, sleeve,
or housing.
Stellite
Stellite is a trade name for a series of cobalt-chromium-tungsten alloys. There are nine variants. It is a very
hard metal with good wear capabilities. It is operable in moderate pH ranges. It does not have the
temperature capabilities necessary for mechanical seal applications. Stellite is no longer a standard mating
ring material available at John Crane. The decreasing cost of tungsten carbide and silicon carbide have
eliminated the need and use of stellite.
42 Seal Identification
Material Identification
Materials and components for seal assemblies are given a part number for identification. These numbers
include a four digit number identifying the material of construction. Part numbers are further explained on
page 48. For most components, the part number is not applied directly to the component. The seal type
number is also not applied to the assembly in most cases. The part number is applied to the packaging and
this is the best method of identifying the component. A common mistake is to attempt to identify a component
or assembly visually without the use of the labeling system. Keeping the component in its packaging is
important for identification and protection of the component. Many materials have the same color but are
different in composition or grade. For example, many primary rings are made of a material generically
referred to as “carbon”, John Crane uses 184 carbon variations, all are black in color. It is impossible to
identify the carbon visually. Using the identification system of part numbers and labels is important.
Seal Identification 43
Figure 8 - Immersion Float Test
Ethylene
Propylene
.86
Water
1.0
Chloroprene Fluorocarbon
1.23 1.85
Labeling
You may be able to distinguish mechanical seal types by visual inspection. However, you will NOT be able to
distinguish component materials visually. Information to correctly identify a seal is found on the box label. For
most seals the box label is the only means of identification. Very few seals have identification markings
directly on the assembly. Seals should not be cannibalized even for emergency purposes. Cannibalization
usually leads to seal failure because many seals visually appear to be the same, but are not. SEAL
ASSEMBLIES SHOULD BE LEFT IN THE FACTORY PACKAGING UNTIL INSTALLATION. If the seal box
does not fit very well on the warehouse shelf, change the shelf.
There are three types of box labels. The box label shown in Figure 9 began use in March 1999. It
incorporates a bar code system. This is the standard label for all John Crane seal types. Two other labels are
shown in Figure 10. These are discontinued labels, one for new seals and one for rebuilt seals. Many of the
discontinued labels are in plant inventories, therefore it is important to understand them. Some of the
information found on the labels can be cross referenced to the seal layout drawing. Material codes are found
on the labels. The material code often includes a sub number that is printed slightly below line. Computer
generated labels may not have sub numbers printed below the text line but on the same line. The label
information is:
44 Seal Identification
DESCRIPTION . . . . . . . . .The type, size, and description.
JOB NUMBER . . . . . . . . . .The John Crane file number containing ordering, engineering, or rebuilding
information.
QUANTITY . . . . . . . . . . . .The number of seal assemblies in the box.
CUST. ORDER NUMBER .The purchasers documentation number.
P.O. NUMBER . . . . . . . . . .The same as customer order number.
CUST. PART NUMBER . . .The purchasers warehousing and storage number.
EQUIPMENT NUMBER . . .The number assigned to the equipment the seal is to be installed into.
BAR CODE . . . . . . . . . . . .An electronic scanning system incorporating all of the listed information.
JCI P/N . . . . . . . . . . . . . . .Uniform bill of materials number (UBM). A list of the assembly components.
Seal Identification 45
Figure 10 - Discontinued John Crane Seal Labels
Bilt-Rite SEAL
GUARANTEED REBUILT TO ORIGINAL STANDARDS
81081 HU-32541
F-SP-16166 59-303-3767
BILT-RITE
John Crane TO SEAL
RIGHT
Morton Grove, IL 60053
Trademarks
A trademark or trade name is a name given to a proprietary material or item by a manufacturer. A trademark
or trade name may or may not be legally registered. In this booklet the materials listed are generically
described. Included with each generic description is the material trade name. The trade names and generic
names are often interchangeably used in the field. Listed below are the companies that own the trademark.
46 Seal Identification
Packaging and Storage
All John Crane mechanical seal assemblies are packaged in accordance with the specification: Packaging
Materials, 10th issue, 1996. The specification lists the packaging materials and techniques necessary to
protect the seal from the time of production, through its transport and delivery to the ultimate user. The
specification is also for the preservation and identification of the seal assembly. The packaging is unique to
each seal design. The packaging used for one seal type may not be used for another. For example, many
small pusher types of seals such as the Type 8 series are contained in plastic shrink wrapping. Plastic shrink
wrapping is not appropriate for other seal types such as the Type 1. Plastic shrink wrapping would be difficult
to remove from a Type 1 assembly. Seal assemblies with large coil springs such as the Type 1 will be
wrapped in a specially treated paper. The wrapping is protective and easily removed.
Proper warehousing procedures can overcome many common problems. The seal assembly should be left in
its protective packaging until it is ready to be installed into the equipment. Boxes should not be opened for
cannibalization. If the box has been opened for inspection, then it should be sealed. The box contains the
identification label that explains every detail necessary to know about the seal. For most seals the box label
is the only means of identification. Very few seals have identification markings directly on the assembly.
The box preserves the seal in order to reach its maximum shelf life. The box is intended to cushion the seal
in order to prevent distortion. All seal components should be protected from dirt, dust, liquid spills, and
vibration. Metal components must be protected from humidity that can cause corrosion. The environment
significantly effects the elastomers used in the seal assembly. It is through proper storage that the maximum
self life of elastomers can be attained. Exposure to heat, moisture, oxygen, ozone, radiation, and ultra violet
light will cause elastomers to deteriorate. The elastomers will be effected by those conditions both in service
and in storage. Storage life varies with each elastomeric compound. Simply storing the elastomeric
component in a plastic bag and cardboard box is sufficient to protect it. Elastomers should be stored in a
temperature range of 60 to 100°F / 15 to 38°C. In most cases it is not age, but the environment that is
significant to the useful life of the elastomers. For many elastomers the actual shelf life is well over ten years.
Other than the elastomers, mechanical seals are made of materials which do not have a restricted shelf life.
Seal assemblies may be installed into a piece of equipment that is in storage. Often pumps are purchased as
new, or rebuilt and then placed in storage for use at a later time. In that situation it is important to have the
seal in a suitable seal chamber environment. The equipment should be stored as follows:
! The seal chamber should be drained of all water to prevent any damage from freezing.
! The annulus of the gland plate should be masked to prevent dirt from entering the area.
! The pump suction and discharge flanges should be covered.
! All ports in the seal chamber or gland plate should be plugged.
! If a sleeve to shaft seam is exposed, the seam may be lightly coated with RTV* compound.
! Seals that are used in hydrocarbon services can have the seal chamber filled approximately one
quarter with oil.
! The shaft should be marked and rotated several revolutions each week.
Seal Identification 47
Part Numbers
Every mechanical shaft seal component manufactured by John Crane is assigned a part number. The part
number assigned to a component is a combination of the detail drawing number and a four digit material
code number. The number assigned is in sequence form providing information about the component.
Included in the number are the seal type, size and material of construction
MATERIAL
DRAWING NUMBER CODE
MATERIAL
DRAWING NUMBER CODE
H 2 0 0 0 1 1 5 7 0 5 5 0
4 Digit Sequential Number
Prefix Drawing Component Size (2")
Size 17 X 22
MATERIAL
DRAWING NUMBER CODE
D 1 7 5 0 3 7 5 9 2 0 5
3 Digit Sequential Number
Prefix Drawing Component Size (1-3/4")
Size 8.5 X 11
Imaginary Decimal Separation
48 Seal Identification
John Crane Part Number Notes
Hyphens: Many part numbers had hyphens separating the segments of the part number. In recent years
hyphens were eliminated in order to adapt the part numbers to computerized systems.
O-rings have an eleven digit number assigned, which combine the drawing number and a four digit material
code number. These numbers conform to the Society of Automotive Engineers Aeronautical Recommended
Practice (ARP 568), Uniform Dash Numbering System for o-rings.
Prefixes: Alpha prefixes generally refer to the size of the paper used for the original drawing. These are
usually the same prefixes used for the same component type. Prefixes were important for paper filing
systems. Computer filing systems continued the use of prefixes simply for referencing.
A - Size 8.5” x 11”, for seal head components.
C - Size 11” X 17”, for seal head components and sleeves.
D - Size 8.5” X 11”, for Types 1 and 2 components, mating rings, and gaskets.
F - Size 11” X 17”, for generic components, sleeves, and gland plate assemblies.
H - Size 17” X 22”, for generic components, sleeves, gland plates, and seal head components.
Numerical prefixes are used following the alpha prefix to designate the seal head type that the component is
used in.
8 - a Type 8 series seal head component.
9 - a Type 9 series seal head component.
Size: The inner diameter of the component, or the seal head inner diameter in which the component is used.
This is designated by four numerical digits following the prefix. Decimal points were not used.
The sequence number at the center of the part number allows three or four numerical digits. Three digits
were used prior to 2001; the use of four digits began in 2001. The number is selected in the order of need.
Prior to 2001 the highest possible number was 999. If all 999 numbers were used, the previous digit in the
size area moved up one number to allow an additional 999 sequence numbers. Example: A9-3501-001-1908,
the size is 3.5”. The center sequence number has no meaning.
Springs are assigned a four digit number. This number combines the detail drawing of the spring with its
material of construction.
Seal Identification 49
Drawings and Booklets
There are several drawing formats used for mechanical seals by John Crane. The seal companies that were
brought together had their own independent format for drawings. The diversification of drawings can lead to
errors. For that reason a new standardized global format for drawings was implemented in 1999. Since many
old drawings remain in the field, it is important that individuals have an understanding of all current and
former drawing formats. All drawings at first glance appear confusing. However, within a few minutes of
reading, the drawing is understandable. The common drawings are described below.
Typical Drawings
These are intended for internal John Crane and original equipment manufacturers. A typical drawing shows a
seal head with several alternate configurations. For example, alternative spring holders, spring adapters,
mating ring types, and gland plate configurations may be shown. The required dimensions for fitting the
assembly are listed. The installation reference is usually not shown on a typical drawing. For that reason end
users should not rely on typical drawings for seal installation. The John Crane drawings format for typical
drawings has a prefix of H-SP. The letter prefix is then followed by a number up to seven digits long,
example: H-SP-654321. Common typical drawing number prefixes are: F-SD and CF-D. For an example of a
typical drawing refer to page 53.
Layout Drawings
These are seal drawings for a specific seal type, application, and end user. The exact seal head, mating ring,
sleeve, and gland plate are shown. This one drawing provides necessary information to several end user
departments such as maintenance, operations, engineering, warehousing, and purchasing. The drawing is
divided into several sections. Reading each section individually makes the whole easy to understand.
Separate sections show the operating conditions, equipment information, component parts, start-up notes,
dimensions, and the installation reference dimension. The John Crane drawings format for layout drawings
has an H-SP prefix. The letter prefix is followed by a number up to seven digits long, example:
H-SP-1234567. Common layout drawing number prefixes are: AD-SP, K-SP, F-SP, CF-SP, and H-SP. For
examples of layout drawings refer to pages 54 - 56.Layout drawing numbers may be followed by a dash
number, example: H-SP-37337-301.
NOTE: Layout drawings provide the installation reference dimension, telling the installer exactly where to
locate the seal on the shaft from the face of the seal chamber. Only the face of the seal chamber is used as a
reference point. No other surface or position is used as a reference point for seal installation. The amount of
seal compression varies, there is not one dimension. If you as the installer set all the seals in your plant at
one amount of compression (crush) such as 1/8”, 3/16”, or 1/4”; you are sure to cause PREMATURE SEAL
FAILURE.
50 Seal Identification
number assigned to the component itself. Information about the material of construction is not supplied on
detail drawings. Detail drawing numbers have single letter prefixes such as: A, D, and F. These letter prefixes
are followed by an eight digit number set, example: A9-1750-398-. Detail drawings have the necessary
information for manufacturing the component. To prevent counterfeiting of components, detail drawings are
not released from John Crane facilities. For an example of a detail drawing refer to page 52.
Installation Booklets
In addition to layout drawings, most cartridge seal assemblies have an accompanying booklet that shows the
dimensional and equipment preparation requirements of the seal as well as a detailed installation procedure.
These are booklets that have been prepared for a specific seal type or series. Another booklet available has
been prepared by the John Crane Training Center to aid the installation of seals, Seal Installation in Pumps,
MMTC 303.
Suggestions
The seal drawing or installation booklet should always be reviewed before installing the seal. The drawing will
provide cross-reference information with the seal box label ensuring the correct seal. Take the extra time to
get the drawing - it may be in the maintenance equipment files, the engineering files, or in the seal box. You
can telephone the local John Crane office to obtain a copy of the drawing.
Seal designs are periodically revised and the revisions are shown on the drawings. You should check to see
whether or not the seal has been revised since it was last installed. If the drawings are illegible or several
decades old, they will require revision. Requests for revisions can be taken by your John Crane
representative or office. When seal assemblies are returned for repair to a John Crane repair center, the
drawing will be reviewed for possible revision. All recent John Crane drawings are produced and engineered
on CAD systems.
Layout drawings are usually 11” X 17” in order to be large enough to be easily read. The CAD drawing format
is 17” X 22”. Customers should always maintain a file on each piece of plant equipment. That equipment file
should include a copy of the seal installation layout drawing. Many customers have plastic laminated layout
drawings inserted into 11” X 17” ring binders. This makes for easy storage and retrieval of the drawing. The
lamination protects it for future use.
NOTE: Even if a maintenance mechanic has been installing seals for twenty years, it does not necessarily
mean he has been installing them correctly for twenty years. ALWAYS READ AND USE SEAL DRAWINGS
AND INSTALLATION BOOKLETS.
Seal Identification 51
Figure 12 - Detail Drawing Example
52 Seal Identification
Figure 13 - Typical Drawing Example
Seal Identification 53
Figure 14 - Layout Drawing Example
54 Seal Identification
Figure 15 - Layout Drawing Example
Seal Identification 55
Figure 16 - Layout Drawing Example - Revisions Required
56 Seal Identification
Addendum No. 1
American Petroleum Institute Standard 610
The John Crane material code system refers to materials of construction only, whereas the API 610 code
includes seal design information with the materials information.
The API 610 code uses alphabetical letters in a sequential order of five symbols. The first, second, and third
symbols refer to the design, using the first letter of the word as a symbol. The fourth and fifth symbols refer to
the materials of construction, using a separate chart of symbols for each sequence position.
Not noted in the code are springs. The spring material for multiple type spring assemblies is Hastelloy C. The
spring material for single type spring assemblies is grade 316 stainless steel. Any deviations from these
standards would be noted. Any other hardware component not referred to in the code would also be grade
316 stainless steel. All materials are to be solid rather than coated or plated.
Seal Identification 57
American Petroleum Institute 610
Mechanical Seal Classification Codes
Combination E F G H I R X Z
Mating Fluoro- Fluoro- PTFE Nitrile FFKM Elastomer Flexible As Spiral Wound
Ring elastomer elastomer (Perfluoro- Graphite Specified Flexible
(Secondary elastomer) Foil Graphite
Seal) Foil
Seal Head PTFE Fluoro- PTFE Nitrile FFKM Elastomer Flexible As Flexible
Unit elastomer (Perfluoro- Graphite Specified Graphite
(Secondary elastomer) Foil Foil
Combination L M N X P
Mating Ring (Seat) Tungsten Carbide - 1 Tungsten Carbide - 2 Silicon As Specified Silicon Carbide
(Cobalt Binder) (Nickel Binder) Carbide
Examples:
B S T I M B T P F X
Balanced As specified (Both primary ring
and mating ring)
Single
Fluoroelastomer
Throttle Bushing in Gland Plate
Plain Gland Plate
FFKM Elastomer
Tandem
Primary Ring = Carbon
Mating Ring = Tungsten Carbide Balanced
(Nickel Binder)
58 Seal Identification
Addendum No. 2
American Petroleum Institute Standard 682
The code dictated in API 682 is a comprehensive specification covering mechanical shaft seals and auxiliary
equipment systems. It includes a code system for mechanical shaft seal identification. Defined is the seal
type, arrangement, piping plan, and size. Materials of construction have been standardized and are not
included in the code. The standardized materials are listed in the materials and specifications sections of the
document. However, limited optional materials may be designated. The code is limited in that only certain
seals, materials, and features can be coded. The limitation is intentional and is designed to discourage the
use of seal designs, materials, and features that have not been considered by the governing committees of
the American Petroleum Institute. The code is shown as a series of four symbols in a sequential order, with
possibly nine explaining digits.
Seal Identification 59
American Petroleum Institute 682
Mechanical Seal Classification Codes
Single Special API Flush “R” for Seal Size: Inch Seals in
type Features Plan Rotating or Hundredths, (for example 1-1/4” is
Code Codes “S” for 125). Metric Seals in Centimeters,
(A, B, C) 2 - Letters Stationary (for example a 60 mm seal is 6)
(R, S)
Note:A seal with two flush plans (such as a vertical with a Plan 32 and a Plan 13), would repeat the flush
code with a hyphen (same format as used for dual seals).
Example:
APS/23/R/200 = A 51 mm (2 inch), rotating, single spring pusher seal with a pumping device and a Plan 23
A PS 23 R 200
Pusher Internal API Flush Rotating Seal Size = 2”
Seal Device Plan 23
Single
Spring
Inner Special Outer Special Inner - Outer Inner - Outer Inner - Outer
Seal Feature Seal Feature Seal Flush Seal Seal
Code Codes Type Codes Plan Rotating or Size
Code Stationary
Example:
A-AP/11-52/R-R/200-175 = An arrangement 2 unpressurized dual pusher seal. The inner seal has no
special features, the outer seal an internal circulating device. The inner seal
is cooled by a Plan 11 and the buffer fluid circulated by means of a Plan 52.
Both seals rotate. The inner seal is a 51 mm (2 inch) and the outer seal is a
44 mm (1-3/4 inch).
Seal Type Codes (1st Symbol, 1st Digit) A = Pusher rotating seal head, multiple spring, O-ring secondary
seals. B = Non-Pusher rotating seal head, metal bellows, O-ring secondary seals. C = Non-Pusher stationary
seal head, metal bellows, graphite secondary seals.
60 Seal Identification
API 682 Standard Materials (Not Included In Code)
Component Material
Primary Ring Carbon
Mating Ring Reaction Bonded Silicon Carbide
O-Rings Fluoroelastomer
Springs Hastelloy C
Sleeve 316 Stainless Steel
Throttle Bushing Carbon
Optional Features / Materials (1st Symbol, 2nd and 3rd Digit)
Code Special Description
A Ammonia Resistant Carbon
B Buna-N (Nitrile, NBR)
C Amine Resistant Perfluoroelastomer
H Two hard Faces, Silicon Carbide vs. Tungsten Carbide
K Perfluoroelastomer
P Internal Circulating Device, Pumping Ring
S Single Spring
John Crane API 682 Codes
John Crane seal types which meet API 682 requirements are identified with a four digit symbol system. An
optional fifth symbol may be applied as a further explanation, but it is not included in the official seal title.
1st Symbol 2nd Symbol 3rd & 4th Symbol 5th Symbol
Arrangement Compliance John Crane Type Optional
1=Single 6=API 682 48=Type 48 LP HP O
2=Dual Unpressurized 1670, 2670, 3670 MP RP RS
3=Dual pressurized 1604, 2609, 3609 (See page 7)
Example: Type 1 6 4 8 HP
Single High Pressure
Seal Identification 61
Addendum No. 3
John Crane Flexibox Identification System
Generic Description: A non-pusher type single arrangement cartridge mount assembly. The assembly
consists of a rolled metal bellows and static o-ring mounted on a sleeve. The mating ring is stationary in the
gland plate. The gland plate has both a flush and quench connection. The quench is contained with a throttle
bushing. The seal assembly size 2 1/4”. The mating ring is silicon carbide and the primary ring is carbon. The
elastomers are fluorocarbon. The hardware is of both 18-8 and 316 stainless steel. The installation drawing is
not included in the code. The installation drawing does list the code.
The first segment will identify these design aspects: hydraulic balance, spring quantity and design, seal
arrangement, mounting position, and assembly.
The second segment defines the assembly size. The size is shown in tenths of a millimeter. Leading zeros
are added when necessary, applying to both metric and inch standard sizes.
The third segment identifies the material of construction. The first digit defines the mating ring material. The
second digit defines the primary ring material. The third digit is the secondary seals. The fourth digit is the
hardware of the assembly.
The fourth segment identifies the country of origin and the seal design number. The first digit is a letter which
codes the country in which the seal was engineered. The second, third, and fourth digit is a design reference
number.
Tailing the four segments may be added an appendix. The technical manual has a table of possible appendix
codes. An appendix code will further describe the assembly. Options such as pumping rings, face designs,
auxiliary equipment, injections, and cooling will be coded in the appendix.
62 Seal Identification
FFGD Pusher type, balanced, single spring, external mount. Slurry, Flue Gas.
FFOL Pusher type, balanced, single spring, external mount. Slurry, RSR.
FFOV Pusher type, balanced, single spring, external mount. Slurry.
FFSP Pusher type, balanced, single spring, external mount. Slurry. South Africa.
FFST Pusher type, balanced, single spring, external mount. Slurry.
FG*M Pusher type, balanced, single spring, external mount. Slurry.
GL1B Non-pusher type, rolled metal bellows. General purpose seal. “Saflex”.
GL7B Non-pusher type, rolled metal bellows. General purpose seal, meets API 682. “Saflex”.
RRAL Pusher type, balanced, single spring, inside mount. Meets API 682.
RREL Pusher type, balanced, single spring, inside mount. Meets API 682. RSR.
RRET Pusher type, balanced, single spring, inside mount.
R*OL Pusher type, balanced, short single spring, inside mount.
SBOP Contacting standby seal assembly.
U2EK Pusher type, unbalanced, multiple spring. “Uniflex”.
Seal Identification 63
7Y Tungsten Carbide, nickel Silicon Carbide
87 Tungsten Carbide, cobalt Tungsten Carbide, cobalt
88 Tungsten Carbide, nickel Tungsten Carbide, cobalt
A2 Silicon Carbide Carbon
A7 Silicon Carbide Carbon, high temp.
C7 Silicon Carbide Silicon Carbide
G1 Silicon Carbide Carbon, combination meets API 682
G2 Silicon Carbide Tungsten Carbide, combination meets API 682
Country of Origin and Design Number Codes (fourth segment, four digits)
Country, first digit
Code Country
A Australia
B Holland
C Canada
D Holland
E Spain
F France
G Germany
H United States of America
J South Africa
L Brazil
M Mexico
N Japan
P Singapore
64 Seal Identification
S Sweden
T International
U United Kingdom
W Norway
Y Italy
X India
Seal Identification 65
Addendum No. 4
John Crane Safematic Identification System
Coding For Safematic Safeseals
The identification code for Safematic Safeseals consists of four segments and identifies the seal type, seal
size, materials of construction, and the installation layout drawing number. The segments are separated by
hyphens. The first segment for the seal type consists of a three digit alphanumeric code. The second
segment for the size is a numerical code up to four digits. The third segment for materials is in a sequential
order of four letters. The order is the mating ring, metal components, secondary seals, and finally the primary
ring. The last segment for the drawing number is six digits.
Generic Description: A pusher type single arrangement component mount seal assembly. An o-ring is the
dynamic secondary seal. The assembly has a single coil spring. The size of the seal is 1.750”. The material
of construction are as follows. The mating ring is of silicon carbide. The metal components are Hastelloy C.
The secondary seals are ethylene propylene. The primary ring is silicon carbide. The reference drawing
number is 1234567.
Type Definitions
The alphanumeric seal types and their fundamental definition is as follows:
SE1 Pusher type, single seal, dynamic o-ring secondary seal, component mounting.
SEW Pusher type, single seal, dynamic o-ring secondary seal, component mounting, quench.
SE2 Pusher type, double seal, dynamic o-ring secondary seal, component mounting.
SB1 Pusher type, single seal, dynamic o-ring secondary seal, cartridge mounting.
SB1-A Pusher type, single seal, dynamic o-ring secondary seal, cartridge mounting, ANSI sizes.
SB2 Pusher type, double seal, dynamic o-ring secondary seal, cartridge mounting.
SB2-A Pusher type, double seal, dynamic o-ring secondary seal, cartridge mounting, ANSI sizes.
SPC Pusher type, double seal, dynamic o-ring secondary seal, high pressure service.
SBG Pusher type, double seal, dynamic o-ring secondary seal, component mounting, refiners.
SAF Pusher type, double seal, dynamic o-ring secondary seal, component mounting, O.E.M.
Size Designations
The inner diameter of the seal head assembly is listed as a decimal size with four digits. An imaginary
decimal point after the first digit.
Code Size
030 30 millimeters.
0500 1/2 half inch.
075 75 millimeters.
0750 3/4 inch.
0875 7/8 inch.
0100 100 millimeters.
1000 1 inch.
1125 1 1/8 inches.
66 Seal Identification
1250 1 1/4 inches.
1625 1 5/8 inches.
1750 1 3/4 inches.
1875 1 7/8 inches.
Material Codes
The material code section is in a sequential order. The first three digits represent the fluid side of the seal, the
fourth digit represents the atmospheric side of the seal. The first digit is the seal faces in the fluid (inboard).
The second digit is the assembly hardware in the fluid. The third digit is the secondary seals in the fluid. The
fourth digit is the seal faces on the atmospheric side of the assembly (outboard).
Second Digit
Code Hardware
R SS 2343/2324
H Hastelloy C
T Titanium
U SS 2562 (UHB 904L), Alloy 20
Third Digit
Code Secondary Seals
M Polytetrafluoroethylene (PTFE)
E Ethylene Propylene (Cranelast, EP, EPDM)
V Fluoroelastomer, (Fluorocarbon)
K Perfluoroelastomer
Miscellaneous Codes
For single seal assemblies the fourth digit in the material code will be a zero (0) since an outboard seal does
not exist. If a quench injection is supplied to the atmospheric side of the seal assembly the fourth digit of the
material code will refer to the quench sealing device, as listed below.
Fourth Digit
Code Sealing Device
P Compression Packing
M Throttle Bushing
V V-Ring
H Radial Lip Seal
Drawing Numbers
The number assigned to the seal assembly layout drawing is the last seven digits listed in the code. The
Seal Identification 67
drawing numbers have no meaning. The drawing numbers are consecutive. The drawing lists both the sizes
and materials of the assembly components.
Part Numbers
Each individual component is assigned a part number. The numbers are from six to eight digits. The part
numbers have no meaning.
Name Number
Sleeve 304038
Spring 21770040
Retainer 304029
68 Seal Identification
Addendum No. 5
John Crane Sealol Identification System
Coding For Sealol Seals
The identification code for Sealol seals consists of fourteen to sixteen digits in ten segments. In order, the ten
segments identify the seal type, design features, hardware materials combination, primary ring material,
mating ring material, mating ring design, secondary seals materials combination, gland plate material, gland
plate design, seal size. The fourth and fifth, and ninth and tenth segments are separated by a hyphen The
drawing number is not included in the code.
Generic Description: A non-pusher type single seal arrangement. The assembly is a Hastelloy C metal
bellows and static o-ring seal head. The seal is for low temperature services. The hardware is of Hastelloy C.
The primary ring is carbon graphite. The mating ring is an o-ring type of Sealide. The secondary seals are of
Flourocarbon. The gland plate is of 316 stainless steel. The gland plate has a flush, and quench, and throttle
bushing. The assembly size is 1.750 inches.
Seal Identification 69
680 Non-pusher, metal bellows, o-ring, Alloy 20.
1010 Retired. Non-pusher, metal bellows, o-ring, non-contacting, dual assembly.
1011 Retired. Non-pusher, metal bellows, o-ring, non-contacting, single assembly.
1012 Retired. Non-pusher, metal bellows, o-ring, non-contacting, compressor service.
3710 Pusher, o-ring, finger spring, fully split assembly.
ECS Non-pusher, metal bellows, o-ring, dual cartridge, emission containment, low or high temperatures.
EZ1 Non-pusher, metal bellows, o-ring, single cartridge, Alloy 20.
70 Seal Identification
Material of Construction Combination Codes (third segment, one digit) (Cont.)
Code Shell Material Bellows Material Drive Collar Material
M Monel 400 Monel 400 Monel 400
N AM-355 AM-350 AM-355
O Seal head assembly not supplied.
P Carp. 20 Carp. 20 Carp. 20 (Machined)
R Carp./Nilo 42 AM-350 Dbl ply 347 SS
T Titanium 2 Titanium 2 Titanium 2
U Cal. Flour./PTFE PTFE/Hast. C Calcium Flouride
V Carp./Nilo 42 AM-350 347 SS
X As specified.
Seal Identification 71
Mating Ring Material Codes (fifth segment, one digit) (Cont.)
Code Material
S Sealide, multiple grade.
T Tungsten Carbide, Cobalt binder.
V Sealide C.
X As specified.
Y Siliconized carbon graphite.
72 Seal Identification
T Kalrez Kalrez Teflon/Gylon
U Kalrez Teflon Teflon
V Kalrez Kalrez Flexitallic
W Kalrez Grafoil Flexitallic
X As specified.
Y Grafoil Grafoil High temp. gasket
Seal Identification 73
Gland Plate Design Codes (ninth segment, two digits) (Cont.)
Note: Odd numbers, non-clamped type mating ring, even numbers, clamped type mating ring.
71 or 72 Jacketed, quench, floating bushing.
73 Quench, deflector, auxiliary packing rings.
75 Quench, deflector and throttle bushing combination.
77 Flush, deflector and throttle bushing combination.
78 Flush, quench, deflector with floating bushing combination.
79 Flush, quench, deflector and auxiliary packing rings.
81 Flush circulated, auxiliary seal, shroud, centering bushing.
83 ECS housing.
85 Flush, buffer or barrier fluid circulated.
88 As specified.
91 Gland adapter/housing without bolt holes.
99 As specified.
Metric Size Note: Always preceded by a “0”, the nominal size in millimeters.
Code Size
030 30 mm.
075 75 mm.
0100 100 mm.
XXX Seal size is not specified.
74 Seal Identification
Addendum No. 6
John Crane 5 Symbol Seal Identification System
In 2001 the 5 symbol seal identification system was superceded by the 7 symbol system (see page
20). This section details the old 5 symbol system.
The John Crane system of identifying the materials of construction uses a five position symbol code that is in
a sequential order. Each symbol identifies a component or group of components in the seal assembly. The
codes are alphabetical letters, numbers, or alphanumeric combinations. The material codes only identify
materials, the seal design, size, or drawing is not included in the code. The component design is not
described by the code. A chart of component designs by material code symbol position is shown on page 21.
The material codes can be found on bills of materials, seal layout drawings, and seal box labels. Because a
material code explains an immense amount of information in a small space, it is used in many engineering
documents. Most notably it is used on application charts (D-SK charts) to explain a recommended set of
materials in a specific fluid and operating conditions.
A letter, number, or alphanumeric combination symbol will have a description that explains all of the material
data. A four digit number is also assigned to that symbol. This is another means of expressing the specific
material. It is attached to end of a component detail drawing number to form a total part number.
The material code is often referred to as the “BRICI” code. It was developed several years ago before the use
of computers and word processors. Then the equipment used for word processing was a typewriter. The
symbols for the material code are the letters, numbers, and marks found on a typewriter. The initial codes
were very simple involving just letters or numbers. With seal technology advancements the material codes
became more complex. Additional numbers were added to existing codes. Other marks found on the
typewriter keyboard were added to the system and are referred to as special notations. Because a word
processor keyboard is essentially the same as a typewriter keyboard the material code system continues with
very little modification. The special notations are explained on pages 77 - 78.
Seal Identification 75
Figure 1 - John Crane 5 Symbol Material Codes
John Crane seal codes designate the materials used in manufacturing a seal. The sequential order of the
code numbers and letters has a specific meaning.
1ST SYMBOL 2ND SYMBOL 3RD SYMBOL 4TH SYMBOL 5TH SYMBOL
Hardware:
Secondary Primary Mating
Retainer, Spring
Seals Ring Ring
Disc, Etc.
1 1
Q F51 C
1 2
B F50 7
76 Seal Identification
John Crane Material Code Special Notations
Subscript Numbers or Index Numbers
Subscript numbers are used with a letter designation. They are used to further describe or explain the letter
designation. They are written immediately to the right side of the original letter. They can be written slightly
below the line the original letter designation is written on or they can be written with a smaller font size. If the
word processor or printing method does not allow subscript numbers or smaller font sizes, then the subscript
number can be written on the same line as the letter with a blank space following it. The subscript will only
further describe the code immediately to its left.
Examples:
P75 - A specific grade of carbon further identified by the subscript of number 75.
O58 - A special material further identified by the subscript of number 58.
X51 - A specific Isolast ™ perfluoroelastomer further identified by the subscript of number 51.
Parentheses
Parentheses are always written at the extreme right of the material code, with only one exception. Within the
parentheses will be written a common description of a material. The parentheses and description will then
further describe any of preceding codes anywhere in the sequence order. The most common usage of the
parentheses involves the further explaining of metals. In the case a multiple seal assembly, the parentheses
are used to the extreme right to contain the words inboard or outboard. For multiple seals the parentheses
explain the position of the seal. The only exception for the parentheses to be on the extreme right is a very
rare exception where it is used with the fourth symbol. If the parentheses contain the fourth symbol, it is
referring to a coated material combination. The indication within the parentheses would be for the base
material. Coatings are extremely rarely used.
Examples:
X51P751C1(316SS) - Further describes the third and fifth symbols, 316 SS for the metal components.
B93F511(5)1 - Indicates that the mating ring (fourth symbol) is coated.
Slash Line
The slash line can be used in any symbol position. It is used to indicate that two components and two
materials are used in the category. It is most commonly used in the first symbol for secondary seals where
the secondary seals for the primary ring and mating ring may be different. The code to the left of the slash
designates the material for the secondary seal at the primary ring. The code to the right of the slash
designates the material for the secondary seal around the mating ring.
Example:
Q/XF31MDM - Indicates a PTFE secondary seal for the primary ring, and a Fluorocarbon secondary seal
for the mating ring.
Seal Identification 77
Straight Line
When a straight line is used in any symbol position is indicates the component consists of two materials. A
code will be above and below the straight line.
Example:
Q
QV1C 3 -Indicates a PTFE coated phosphor bronze spring.
Dash
A dash line used in any symbol position indicates the absence of the specific component. The component is
either not necessary or is not supplied by John Crane.
Examples:
1F71O95- The dash in the fifth symbol indicates that a spring is not necessary in the assembly.
BF511-1 The dash in fourth symbol indicates that the mating ring is not supplied.
Example:
QF51HCH (Inboard) XP90171 (Outboard)
Notes:
Do not randomly modify the system to meet the needs at hand. All of the symbols used have a specific
meaning. To incorrectly use a symbol may change the meaning of the entire code. The Following are
examples of commonly used corrupt codes.
Examples:
XF(51)1D1 - This is an incorrect use of parentheses to note a subscript number.
XP/661C1 - This is an incorrect use of the slash line to note a subscript number.
XO-58H0-58H - This is an incorrect use of the dash line to note a subscript number.
Miscellaneous
Modifications to the code system are often required as a result of the means used for printing the code. Some
systems may only allow a limited number of digits. Some systems may not permit the use of subscript
numbers. In this case blank spaces are often used to separate the five symbols.
78 Seal Identification
Figure 2 - Pictorial Description of a John Crane 5 Symbol Material Code
1ST SYMBOL 2ND SYMBOL 3RD SYMBOL 4TH SYMBOL 5TH SYMBOL
SECONDARY PRIMARY HARDWARE MATING SPRING
SEAL RING RETAINER RING
DISC, ETC.
Bellows Types 1 & 2 Metal Bellows 609 Types 1, 2 & 21 Types 1, 2 & 21 O-Ring Multiple Coil
O-Ring Types 8 & 48 Metal Bellows 680 Type 8 Types 8 & 9 Rectangular O-Ring Single Coil
Wedge Type 9 Mating Ring Gaskets Type 48 Collars, Rings, Pins Floating L-Pinned Single Wave
Screws
Pinned O-Ring
Gland
Plate
Seal Identification 79
Addendum No. 7
John Crane 7 Symbol Seal Identification System
By Dennis Overton
To assist our customers in identifying John Crane products, John Crane Inc. has developed a “Seal
Identification Coding” schema which uniquely defines the major components of the seal specific to their
materials of construction. The code allows for easy identification of products to application requirements. It
should be noted that the seal identification coding schema is not designed to identify every component of the
seal but only those components critical to a successful sealing applications. Over the years the John Crane
“Seal Identification Coding” schema has been enhanced and expanded to accommodate new products and
improve understanding. Under that context this section is offered to explain and clarify the John Crane Inc.
“Seal Identification Coding” schema. The superceded 5 position code is explained in Addendum 6.
The new John Crane ”Seal Identification Coding “ schema consists of seven (7) fields. Each field defines a
major seal component or grouping of components. The position of these fields is critical to seal material
identification. Therefore, the “Seal Identification Coding” schema is a positional coding schema. Each field is
defined by a position and given a naming convention of 1st Symbol through 7th Symbol. Alpha, numeric or
alpha–numeric coding symbols have been established to define the primary materials supplied for John
Crane mechanical seal products. Fields 1st Symbol through 7th Symbol are populated using the appropriate
material coding symbol for the component or grouping of components defined by the field which are supplied
as part of the product. To maintain this positional coding schema a dash “-” is inserted into any position in
which the item defined by that position is not supplied as part of the mechanical seal. A listing of the most
popular material coding symbols begins on page 23. It should be noted that this coding schema is used to
define mechanical seal assemblies only and does not extend to other John Crane products. It is used to
define various mechanical seal related assemblies such as “mating ring assemblies, hardware assemblies,
seal head assemblies, and seal assemblies. Mating ring assemblies are the simplest and consist of the
mating ring with its secondary sealing element(s). Hardware assemblies are typically a grouping of the seal
assembly hardware items. Seal head assemblies are the seal heads themselves less mating ring assemblies
and less equipment adaptive hardware. Seal assemblies typically fall into two categories. 1- The seal head
assembly complete with an applicable mating ring assembly or 2 - Complete seals which include the seal
head assembly, mating ring assembly and equipment adaptive hardware. The later includes complete seal
assemblies, cartridge seal assemblies and package seal assemblies. Though equipment adaptive hardware
items such as gland plates, sleeves, collars, etc. may be included with the product, the equipment adaptive
hardware is not defined by this “Seal Identification Coding” schema.
In the past John Crane seal assemblies which incorporated two or more seals in a double, dual or tandem
seal arrangement used a concatenated version of the “Seal Identification Coding” schema . This practice has
been discontinued and is no longer used. Instead each seal is now independently defined with its own seal
type, size, drawing and seal identification code. For double, dual and tandem seal arrangements the seal
closest to or in the product being handled is defined as the inboard seal assembly while the seal farthest from
the product is defined as the outboard seal assembly. As John Crane Inc moves forward with this new Seal
Identification Coding schema all customer documentation, drawings, acknowledgements, labels, etc. will
begin to reflect this procedure. Single seals will have one set of information, double, dual and tandem seals
will reflect two sets of information: one for each seal. It is critical to those creating the JCI “Seal Identification
80 Seal Identification
Coding’ schema that the positions define the correct materials for the correct seal assembly. In the pictorial
representation each field is labeled 1st Symbol through the 7th Symbol. A further definition of the fields and
their use follows.
1st Symbol The first symbol defines the secondary sealing element used in conjunction with the seal head
assembly primary ring. The symbol used defines the sealing element only. Anti-extrusion rings,
support rings, cove rings, shields, etc. are NOT defined by this code.
The bellows for metal bellows seals traditionally defined in this position has been moved to the
sixth symbol labeled “Loading Device”.
2nd Symbol The second symbol defines the seal primary ring material. Traditionally, most primary rings
are made up of a single material. The primary ring coding symbol defines either a family
material or a very specific face material. As the primary ring is the primary sealing element of
the seal, this symbol only concerns itself with the primary ring material. When the primary ring is
an insert pressed into an adapter, as in the case of metal bellows seals, the insert is the only
component defined by this symbol.
Seal Identification 81
3rd Symbol The third field defines the hardware items for the seal assembly. It does not include the
equipment adaptive hardware such as glands, sleeves or collars used to fit the seal to the
equipment. The term hardware relates to the major components of the seal assembly such as
the retainer for seal types 1,2, 21, 8 & 9, drive sleeve for type 6 & 6A seals. Back and front
adapters for metal bellows type seals. When the metallurgy of these items is not specific as “1”
for stainless steel the seventh field is used to clarify the specific grade of stainless. Reference
field seven for further information
4th Symbol The forth field defines the secondary sealing element used specifically with the mating ring.
Like the first field it defines only the sealing element. PTFE cove rings, anti-extrusion rings, etc.
are NOT defined by this code. O-rings, gaskets, spiral gaskets, Cranefoil rings, rubber cups are
examples of mating ring secondary sealing elements. Clamped in mating rings are
traditionally supplied with two gaskets of different materials. Only the gasket in contact with the
product is to be defined.
82 Seal Identification
5th Symbol Defines the material for the mating ring. See the primary ring rules.
6th Symbol The sixth symbol defines the material of the loading devise, typically the spring for most
traditional seals. The exception is metal bellows seas, in which the bellows acts as both a
sealing element and a loading devise. Because metal bellows seals incorporate a secondary
sealing element such as a metal wedge, Cranefoil ring, or O-ring to seal the shaft and because
the bellows acts as the primary loading device it has been been moved to this field.
7th Symbol Defines more specifically the metallurgy used for both the hardware items (3rd symbol) and the
loading device (6th symbol) of the “Seal Identification Code”. This information is required
because the codes used for these fields are generic. Because they are not specific they must
be further defined to distinguish the specific material grades. For example “1” defines stainless
steel, however there are multiple stainless steel grades that can be used, 304 SS, 18-8 SS,
302 SS, 347 SS, 316 SS, etc. The same is true for “H” which is used for Hastelloy. There are
multiple grades of Hastelloy such as Hastelloy C-267, Hastelloy B, Hastelloy G, etc. To insure
consistent metallurgy for both positions they are defined in this 7th symbol. Metal bellows seals
are handled somewhat differently: the 7th symbol defines the John Crane IBM code for the
combination of the materials for the front adapter, bellows, and back adapter.
* Because the metal bellows seals are an exception, please reference Table 1 on page 87 for
additional metal bellows information.
Seal Identification 83
Seal Identification
Figure 1 - John Crane Material Codes
John Crane seal codes designate the materials used to manufacture a seal. The sequential order of the code numbers and letters has a specific meaning.
1ST SYMBOL 2ND SYMBOL 3RD SYMBOL 4TH SYMBOL 5TH SYMBOL 6TH SYMBOL 7TH SYMBOL
Q F51 C
1 B F50 7
84
Figure 2 - Pictorial Description of a Seven Digit John Crane Material Code
Seal Identification
1ST SYMBOL 2ND SYMBOL 3RD SYMBOL 4TH SYMBOL 5TH SYMBOL 6TH SYMBOL 7TH SYMBOL
Secondary Primary Hardware: Secondary Mating Loading Metallurgy
Seal for Ring Retainer, Seal for Ring Force 3rd / 6th
Primary Ring Disc, Etc. Mating Ring
Bellows Types 1 & 2 Types 1, 2, & 21 Types 1, 2, & 21 Gaskets, O-Rings, Pinned O-Ring Multiple Coil Spring
O-Ring Types 8 & 48 Type 8 Types 8 & 9 Rectangular O-Ring Single Coil Spring
Clamped-In
Compression Ring 600 Series
Type 37 Metal Bellows
Modified Clamped-In
PTFE Bellows
Type 20
Metal Bellows
Wedge O-Ring Grafoil
Note: Seal adaptive hardware including glands, sleeves, collars,
pins, screws, etc. are not described by this code.
85
Special Notations
Parentheses ( )
When used in connection with the 2nd and 5th symbols for
XF511X(1)H 316/HC
primary rings and mating rings, parentheses indicate that
316 SS mating ring with a coating or
the primary ring or mating ring has a coating or coated face.
coated face
The symbol inside the parentheses indicates the base material.
Note: Coatings are rarely used today as there are a number of
new materials available with superior performance and low cost.
Slash Line /
XF511X(1)H 316/HC
Commonly used today in connection with the 7th symbol to segregate
Seal hardware items in 316 SS with
the materials of the seal hardware 3rd symbol verses the material
a hastelloy “C” spring
for the loading device 6th symbol. The loading device for most
Note: If metallurgy for hardware and
mechanical seals will be the spring(s). For metal bellows seals the
spring is the same it is written as
loading device is defined as the bellows. If the hardware or loading
316/316.
device is not supplied then a dash is use on the appropriate side of
The slash line to indicate it being missing. ( - / 316). Additionally,
even if a more standard material is supplied such as brass (2) it is
Still defined in this 7th symbol as (BRASS/316)
Dash -
A dash inserted in place of any material code indicates the absence X F511 - - 1 316/316
of that specific component for the item being supplied. Seal head only, no mating ring
secondary seal or mating ring
Note:
The above symbols have specific meanings. Incorrect use of a
symbol may change the meaning of the entire code.
86 Seal Identification
Seal Identification
Seal Prim. Ring Adapt. Brici Bellows Material Brici Secondary Adapter Brici Hardware & Loading Device
Type (Hardware) Field 3 Code (Loading Device) Fld 6 Code (Hardware) Field 3 Code (Metallurgy) Fld 3 / Fld 6 =Fld 7
613, 670, ECS Hastelloy C H Hastelloy C H Hastelloy C H 0690
680 Alloy 20 1 Alloy 20 1 Alloy 20 1 0560
605BK, ECS Alloy 42 O103 AM-350 O104 347SST O105 6380
605HN, ECS Alloy 42 O103 INC 718 O72 INC 600 O93 6381
605ME INC 600 O93 INC 718 O72 INC 600 O93 8570
2800MB Hastelloy C H Hastelloy C H Hastelloy C H 0690
285 INC 625 O93 INC 718 O72 INC 625 O93 6382
Secondary Adapter
(Hardware)
Bellows
(Loading Device)
88 Seal Identification
Europe Latin America Middle East, Africa, Asia North America
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Tel: 44-1753-224000 Tel: 55-11-3371-2500 Tel: 971-4-3438940 1-800-SEALING
Fax: 44-1753-224224 Fax: 55-11-3371-2599 Fax: 971-4-3438970 Tel: 1-847-967-2400
Fax: 1-847-967-3915
For your nearest John Crane facility, please contact one of the locations above.
If the products featured will be used in a potentially dangerous and/or hazardous process, your John Crane representative should be consulted prior to their selection and use.
In the interest of continuous development, John Crane Companies reserve the right to alter designs and specifications without prior notice. It is dangerous to smoke while handling
products made from PTFE. Old and new PTFE products must not be incinerated.
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