Sr.

Number:OISD/DOC/2013/158
Page No. I
OISD - STD-164
Second edition: July, 2012

FOR RESTRICTED CIRCULATION ONLY

FIRE PROOFING OF STEEL SUPPORTING STRUCTURES

IN OIL & GAS INDUSTRY

OISD – STD – 164

First Edition, July, 1998
Second edition: July, 2012

Oil Industry Safety Directorate

Government of India
Ministry of Petroleum & Natural Gas
8th Floor, OIDB Bhavan, Plot No. 2, Sector – 73, Noida – 201301 (U.P.)
Website: www.oisd.gov.in
Tele: 0120-2593800, Fax: 0120-2593802
 Sr.Number:OISD/DOC/2013/158
Page No. II

OISD - STD-164
First edition: July, 1998
Second edition: July, 2012

FOR RESTRICTED
CIRCULATION ONLY

FIRE PROOFING OF STEEL SUPPORTING STRUCTURES

IN OIL & GAS INDUSTRY

Prepared by:

FUNCTIONAL COMMITTEE ON
FIRE PROOFING OF STEEL SUPPORTING STRUCTURES IN OIL & GAS INDUSTRY

OIL INDUSTRY SAFETY DIRECTORATE

GOVERNMENT OF INDIA
MINISTRY OF PETROLEUM & NATURAL GAS
8th FLOOR, OIDB Bhavan, Plot No 2
Sector-73, Noida - 201301 (Uttar Pradesh)
Website: www.oisd.gov.in
 Sr.Number:OISD/DOC/2013/158
Page No. III

Preamble

Indian petroleum industry is the energy lifeline of the nation and its continuous performance is essential
for sovereignty and prosperity of the country. As the industry essentially deals with inherently inflammable
substances throughout its value chain – upstream, midstream and downstream – Safety is of paramount
importance to this industry as only safe performance at all times can ensure optimum ROI of these
national assets and resources including sustainability.

While statutory organizations were in place all along to oversee safety aspects of Indian petroleum
industry, Oil Industry Safety Directorate (OISD) was set up in 1986 Ministry of Petroleum and Natural
Gas, Government of India as a knowledge centre for formulation of constantly updated world-scale
standards for design, layout and operation of various equipment, facility and activities involved in this
industry. Moreover, OISD was also given responsibility of monitoring implementation status of these
standards through safety audits.

In more than 25 years of its existence, OISD has developed a rigorous, multi-layer, iterative and
participative process of development of standards – starting with research by in-house experts and
iterating through seeking & validating inputs from all stake-holders – operators, designers, national level
knowledge authorities and public at large – with a feedback loop of constant updation based on ground
level experience obtained through audits, incident analysis and environment scanning.

The participative process followed in standard formulation has resulted in excellent level of compliance
by the industry culminating in a safer environment in the industry. OISD – except in the Upstream
Petroleum Sector – is still a regulatory (and not a statutory) body but that has not affected implementation
of the OISD standards. It also goes to prove the old adage that self-regulation is the best regulation. The
quality and relevance of OISD standards had been further endorsed by their adoption in various statutory
rules of the land.

Petroleum industry in India is significantly globalized at present in terms of technology content requiring
its operation to keep pace with the relevant world scale standards & practices. This matches the OISD
philosophy of continuous improvement keeping pace with the global developments in its target
environment. To this end, OISD keeps track of changes through participation as member in large number
of International and national level Knowledge Organizations – both in the field of standard development
and implementation & monitoring in addition to updation of internal knowledge base through continuous
research and application surveillance, thereby ensuring that this OISD Standard, along with all other
extant ones, remains relevant, updated and effective on a real time basis in the applicable areas.

Together we strive to achieve NIL incidents in the entire Hydrocarbon Value Chain. This, besides other
issues, calls for total engagement from all levels of the stake holder organizations, which we, at OISD,
fervently look forward to.

Jai Hind!!!

Executive Director

Oil Industry Safety Directorate

 Sr.Number:OISD/DOC/2013/158
Page No. IV

FOREWORD

Oil Industry in India is more than 100 years old. Over the years a variety of
practices have been in vogue because of collaboration/ association with different
foreign companies and governments. Standardisation in design, operating and
maintenance practices was hardly in existence at a national level. This lack of
uniformity, coupled with feed back from some serious accidents that occurred in
the recent past in India and abroad, emphasised the need for the industry to
review the existing state of art in designing, operating and maintaining oil and
gas installations.

With this in view, the Ministry of Petroleum and Natural Gas in 1986
constituted a Safety Council assisted by the Oil Industry Safety Directorate (OISD)
staffed from within the industry in formulating and implementing a series of self
regulatory measures aimed at removing obsolescence, standardising and upgrading
the existing standards to ensure safer operations. Accordingly, OISD constituted a
number of functional committees comprising of experts nominated from the
industry to draw up standards and guidelines on various subjects.

The present document on ‘Fire Proofing of Steel Supporting Structures in Oil

& Gas Industry’ was prepared by the Functional Committee on Fire Proofing. This
document was prepared based on the accumulated knowledge, experience of
industry members and various national/international codes and practices.

This document will be reviewed periodically for improvements based on

the new experiences and better understanding.

Suggestions from industry members may be addressed to:

The Coordinator,
Functional Committee on
‘Fire Proofing of Steel Supporting Structures in Oil & Gas Industry.’
Oil Industry Safety Directorate
8th FLOOR, OIDB Bhavan, Plot No 2
Sector-73, Noida - 201301 (Uttar Pradesh)
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Page No. V

NOTE

OISD (OIL INDUSTRY SAFETY DIRECTORATE) publications are prepared

for use in the oil and gas industry under Ministry of Petroleum & Natural Gas.
These are the property of Ministry of Petroleum & Natural Gas and shall not be
reproduced or copied and loaned or exhibited to others without written consent
from OISD.

Though every effort has been made to assure the accuracy and reliability
of the data contained in these documents OISD hereby expressly disclaims any
liability or responsibility for loss or damage resulting from their use.

These documents are intended to supplement rather than replace the

prevailing statutory requirements.
 Sr.Number:OISD/DOC/2013/158
Page No. VI

FUNCTIONAL COMMITTEE OF FIRST EDITION

ON
FIRE PROOFING IN OIL & GAS INDUSTRY

NAME DESIGNATION ORGANISATION

LEADER

Shri B. K. Raut DGM (SMMS) E.I.L

MEMBERS

Shri R. P. Saxena DGM (M) MRBC, ONGC

Shri S.G. Subrhamoney CH.MGR, (PROJECTS), HPCL

Shri S. Neelakantan SR.MGR(ENGG.SERVICES) MRL

Shri B. K. Singh SR. INSP. MGR IOC

Shri H.C. Mehta SR. MGR. (LPG-OPER) HPCL (MKTG)

Shri U. V. Mannur MGR (LPG – ENGG) IOC (MKTG)

Shri B.S.M. Krishna MGR (ADV ENGG-CIVIL) BPCL

MEMBER COORDINATOR

Shri K. R. Soni ADDL.DIRECTOR (ENGG) OISD

===================================================================
In addition to the above, several other experts from Industry contributed in the
preparation, review and finalisation of this document.
 Sr.Number:OISD/DOC/2013/158
Page No. VII
FUNCTIONAL COMMITTEE OF SECOND EDITION
ON
FIRE PROOFING OF STEEL SUPPORTING STRUCTURES IN OIL & GAS INDUSTRY

NAME ORGANISATION

LEADER

Shri P. P. Lahiri Engineers India

Limited.

MEMBERS

Shri P. K. Dewari IOCL - BGR

Shri O.P. Khokhar IOCL (PIPELINES)

Shri G. Deka Numaligarh Refinery (NRL)

Shri R. K. Sachdeva IOCl (REF)

Shri Joydeep Mazumdar IOCL (MKTG)

Shri V. Suresh Kumar BPCL (KR)

Shri M.N.Nagaraja BPCL (MR)

Shri J R Divekar HPCL (REF)

Shri G.K.Dey CHT

Shri Suvir Singh CBRI, ROORKEE

MEMBER COORDINATOR

Shri Y.P.Gulati OISD

===================================================================
In addition to the above, several other experts from Industry contributed in the
preparation, review and finalisation of this document.
 Sr.Number:OISD/DOC/2013/158
Page No. VIII

CONTENTS

Sl. No. SUBJECT Page No.

1.0 INTRODUCTION 01

2.0 SCOPE 01

3.0 DEFINITION 01

4.0 OBJECTIVES OF FIRE PROOFING 01

5.0 AREA WISE APPLICATION 03

6.0 FIREPROOFING MATERIALS AND SYSTEMS 07

7.0 INSTALLATION OF FIREPROOFING SYSTEMS 09

8.0 METHODS OF APPLICATION OF FIREPROOFING 11

9.0 QUALITY CONTROL IN APPLICATION OF FIRE PROOFING. 13

10.0 PERIODIC INSPECTION AND MAINTENANCE 14

11.0 REFERENCES 15

LIST OF ANNEXURES TO THE DOCUMENT

FIRE SCENERIOS AND FIREPROOFING
Annexure -I

TESTING OF FIRE PROOFING MATERIALS

Annexure -II

Annexure - III PARTIAL DIRECTORY OF FIRE TEST LABORATORIES

TEST RATINGS- STRUCTURAL STEEL FOR OIL

Annexure - IV
INDUSTRY

TYPICAL DETAILS – CEMENT CONCRETE

Annexure - V
FIREPROOFING - SOLID ENCASEMENT

TYPICAL DETAILS OF COVER PLATES FOR WEATHER

Annexure - VI
PROTECTION

TYPICAL DETAILS DEPICTING FIREPROOFING

Figure – 5.1 to 5.6
REQUIREMENTS
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FIRE PROOFING OF STEEL SUPPORTING STRUCTURE IN OIL
& GAS INDUSTRY

FIRE PROOFING OF STEEL SUPPORTING STRUCTURES

IN OIL & GAS INDUSTRY

1.0 INTRODUCTION
This standard provides technical details, including inspection and maintenance requirements, for
selection and application of fire proofing in Oil and Gas Industry.

Only passive fire proofing systems have been covered in this standard and details of active systems
such as automatic water deluge, which are used to protect pressure vessels, processing structures,
equipment etc., are excluded. Passive fire protection shall be used along with active fire protection
systems like water deluge sprinkler systems etc.

2.0 SCOPE
This standard provides minimum requirements of passive fire proofing for steel supporting
structures of on-shore installations for exploration & production, refineries, petrochemicals and
marketing installations.
This standard is not applicable to offshore installations.
The standard also covers technical details of materials used for fire proofing, fire rating, selection
and application methods for different areas, methods of application of fire proofing materials, quality
control measures and inspection during application of materials, including periodic inspection and
maintenance of fire proofing. Active fire protection system and its effects are beyond the scope of
this standard.

3.0 DEFINITIONS
i) Fire Proofing: Fire proofing is an insulation that provides a degree of fire resistance to protect
substrates of vessels, piping and structures for a predetermined time period against fire.
ii) Fire-Exposed Envelope: A fire-exposed envelope is the three-dimensional space into which fire
potential equipment can release flammable or combustible fluids that are capable of burning long
enough and with enough intensity to cause substantial property damage.
iii) Fire Rating is the duration of fire test exposure to which a component or construction assembly
is exposed and for which it meets all the acceptable criteria as determined by relevant standard.
iv) Flammable (or inflammable) product: Any product which when tested in a specified manner will
ignite when mixed with air on contact with a flame and will support combustion.
v) Shall indicate that the provision is mandatory.

vi) Should indicate that the provision is recommendatory as per good engineering practices.
vii) Substrate is the underlying layer being protected by a fireproofing barrier layer.

4.0 OBJECTIVES OF FIRE PROOFING

4.1 General
Fireproofing is considered as one of the most effective means of protecting the steel structures. One
of the options available to mitigate damage caused by fire is fireproofing of structures. It offers
protection against the adverse thermal effects of fire for a limited period and limited degree of
exposure. It should never be considered as a replacement for active fire fighting.
The main objective of fireproofing of steel supports and structures is to prevent the escalation of fires
to an unacceptable level by providing a protection for a limited period of time until full fire protection
capabilities can be deployed. Fireproofing is done to maintain the integrity and stability of the
structure to its design functional objectives in order to prevent injury to personnel working within or

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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FIRE PROOFING OF STEEL SUPPORTING STRUCTURE IN OIL
& GAS INDUSTRY

outside the industry premises due to release of large quantities of flammable products and/or toxic
materials.

Application of fireproofing will delay an eventual collapse of steel structures and allow it to happen in
gradually controlled manner with visible signs. This helps in timely isolation of the affected equipment
and carrying out safe fire fighting and rescue operations.
Refrigerated or cryogenic liquefied gases exert an intense cooling effect when escaping to
atmosphere, which may expose unprotected steelwork to severe embrittlement and failure due to
fracture. One of the most effective and well proven means of protection against such hazards is
fireproofing.
4.2 General application criteria
4.2.1 Fire protection

Fireproofing shall be applied to the steel supporting structures, whose sudden failure would lead to
endangering the lives of operating personnel, escalation of the incident or unacceptable
environmental pollution. Only the steel structures located within the fire exposed envelope shall be
considered for fireproofing.
Fire proofing is normally not provided for the following:
i) Top surfaces of the beams, which support floor plates, gratings or equipment.
ii) All the stairways, walkways and platforms etc which are designed for live loads.
For all the steel stanchion or supports requiring resistance against mechanical damage at the lower
end, fire proofing should preferably be made of reinforced cement concrete or otherwise suitable
means should be provided to protect the fire proofing from mechanical damage. The height of such
fire proofing shall be a minimum of 1.8 M from the grade level. However, at higher levels, alternative
fireproofing materials can be used.
4.2.2 Cold splash protection

Steel structure members which are under the danger of embrittlement due to cooling effect of the
product released through potential sources of leaks should be protected against cold splash.

4.3 Resistance against fire and cold splash

4.3.1 General
The criteria for judging a material's thermal performance in a fire exposure should be actual fire tests
on a sufficiently large enough scale to realistically determine the behaviour of both the material and
the installation design. Test environments should closely match the fire exposure expected in an end-
use situation. In the case of the hydrocarbon processing industry, this could be anything from free
burning pools of liquid to high pressure jets of hot hydrocarbons. Therefore, it is imperative to test
materials in as severe an environment as possible.
4.3.2 Resistance against fire

The length of time during which a steel structure needs to maintain its integrity depends on local
circumstances such as type of plant, availability of fire-fighting services, and risk of escalation.
Due to high severity of hydrocarbon fire in comparison to cellulose type fire, all the fireproofing
systems for hydrocarbon fires shall meet the high rise hydrocarbon fire curve criteria mentioned
under UL1709 fire resistance tests for the duration of predicted fire exposure. (A brief write up about
testing of fireproofing materials is attached as ANNEXURE-II to this document.)
50 mm thick cement concrete cover of grade or proportion as specified at clause no 8.8.1 of this
document, meets the above hydrocarbon fire requirement. Systems based on other types of
fireproofing materials shall be referred as ‘other than cement concrete fireproofing systems’ as per
the scope of this standard. To establish fire rating of alternative materials appropriate tests or
calculations can be done. Results of the tests performed on new materials shall be as good as
those of the cement concrete.
“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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FIRE PROOFING OF STEEL SUPPORTING STRUCTURE IN OIL
& GAS INDUSTRY

4.3.3 Resistance against cold splash

The fireproofing system should be able to withstand the atmospheric boiling temperature of the
product while the temperature of the steel structure should not fall below its embrittlement
temperature. To meet the above cold splash protection, 50 mm thick cement concrete cover should
be provided.

4.4 Design considerations

4.4.1 Extent of fireproofing

The extent of the fireproofing around equipment and structures shall be based strictly on the detailed
fire assessment study and the same should be clearly indicated on layout and construction drawings.

4.4.2 Type of fireproofing

The type of fireproofing material and its construction/application method should be clearly specified.
If necessary, heat transfer calculations should be made to determine the fireproofing thickness for
different Hp/ANote1 ratios of sections to be protected, the need for reinforcement and the need for
insulation. Reinforced and/or precast cement concrete can also be considered as an alternative to
fireproofed structural steel.

Note 1: Hp is the exposed perimeter and A is the cross sectional area of the substrates.

4.4.3 Structural members to be fireproofed

Structural members or bracings within a fire exposed envelope which are required for reducing the
effective buckling length of the stanchions shall be fireproofed. Structural members serving only a
windbracing function shall not be fireproofed.

5.0 AREAWISE APPLICATION

Determination of fire proofing needs involves a three step procedure that establishes:

a) The location of fire-hazardous areas or fire-exposed envelopes,

b) The size of the fire-exposed envelope, and
c) The rating or thickness of fire proofing material that needs to be applied within each of the fire-
exposed envelope.
5.1 FIRE POTENTIAL EQUIPMENT CLASSIFICATION
Fire-potential equipment includes types of hydrocarbon-handling equipment that can release
appreciable quantities of flammable fluids.

5.1.1 High Fire Potential Equipment :

a) Fired heaters that charge liquid or mixed phase hydrocarbons, under the following conditions:

i. Operation at temperatures and flow rates that are capable of causing coking within the tubes.
ii. Operation at pressure and flow rates those are high enough to cause large spills before the
heater can be shut in.
iii. Charging of potentially corrosive fluids.
iv. Incorporation of a high level of automation and complex peripheral equipment such as
combustion air preheater.

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
 Sr.Number:OISD/DOC/2013/158
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FIRE PROOFING OF STEEL SUPPORTING STRUCTURE IN OIL
& GAS INDUSTRY

b) Pumps that handle flammable and combustible liquids at or above their flash point or
autoignition temperatures, at high pressure, or at high flows. In some cases, maintaining
seals without serious leaks may be difficult because of the liquid being pumped.
c) Reactors that operate at high pressure or are apt to produce exothermic or runaway
reactions.

d) Compressors along with related lube-oil system. Compressors do not have a high liquid - fire
potential; however, they can generate a fire-exposed envelope if the likelihood exists that
there will be a prolonged release of gas and intense fire in the vicinity of important structural
supports.
e) Heat exchangers handling high temperature fluids at high pressure.
f) Pressure vessels handling light hydrocarbons e.g. C2, C3 and C4 (Reflux).
5.1.2 Medium Fire Potential Equipment :
a) Accumulators, feed drums, and other vessels that may leak as a result of broken
instrumentation, ruptured gaskets, or other apparatus.
b) Tower that may leak as a result of broken gauge columns or gasket failure on connected piping
and bottom reboilers.
5.1.3 Low Fire-Potential Equipment :
Note-2
a) Pumps that handle excluded class liquids below their flash points.
b) Piping that is within battery limits and has a concentration of valves, fittings, and flanges.
c) Heat exchangers that may develop flange leaks.
0
Note-2: Liquids having flash point of 93 C and above

5.2 SIZE OF FIRE-EXPOSED ENVELOPE:

A frequently used frame of reference for a fire-exposed envelope is one that extend 20-30 feet (6.1-
9.1 meters) horizontally and 30-40 feet (9.1-12.2 meters) vertically from a source of liquid fuel.

The following conditions within the fire-exposed envelope can either limit or extend the envelope’s
reference dimensions:

i. The source & volume of the leak.

ii. Pressure and possible leak rates.
iii. The surface drainage area and capacity of the drainage system.
iv. The fuel’s burning rate.
v. The fuel’s heat of combustion.

5.3 FIREPROOFING INSIDE PROCESSING UNITS :

5.3.1 Multilevel Equipment Structures:
a) When structures support fire-potential equipment, fireproofing shall be used for the vertical and
horizontal steel support members from the grade up to the highest level at which the equipment
is supported (see Figure 5.1).
b) Elevated floors and platforms that could retain significant quantities of liquid hydrocarbons
shall be treated as though they were on the ground floor level, for the purposes of calculating
vertical distances for fireproofing.(See figure 5.6)
c) For the structures supporting non-fire potential equipment, fireproofing shall be provided for
the vertical and horizontal steel members from grade up to and including the level that is
nearest to a 30-foot (9.1 meter) elevation above grade if the collapse of unprotected structural
supports could result in substantial damage that would involve nearby fire-potential equipment
(see Figure 5.2).

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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FIRE PROOFING OF STEEL SUPPORTING STRUCTURE IN OIL
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d) Fireproofing shall be used for knee and diagonal bracing that contributes to the support of
vertical loads or to the horizontal stability of columns if it is located within the fire-exposed
envelope. Knee and diagonal bracing that is used only for wind, earthquake, or surge loading
need not be fireproofed (see Figure 5.1).

e) When reactors, towers, or similar vessels are installed on protected steel or reinforced concrete
structures, fireproofing materials shall be used for protection of supporting steel brackets, lugs,
or skirts (see Figure 5.1). The insulating effect of the fireproofing material must be considered
in the design of supports for vessels that operate at high temperatures.
Because of the size and importance of large vessels such as reactors, regenerators and
vacuum towers that are mounted on high support structures, fireproofing should be provided for
the entire exposed support system regardless of its height.

f) Except for the upper surface of the top flange, fireproofing shall be provided for beams that
support equipment in fire-exposed areas.

g) The earthing lugs shall be kept clear of the fire protection.

5.3.2 Support For Pipe Racks :
a) When a pipe rack is within a fire-exposed envelope, fireproofing shall be used for all vertical
and horizontal supports upto and including the first level (see Figure 5.3.).
b) If a pipe rack carried piping handling hydrocarbon that has a diameter greater than 6 inches at
levels above the first horizontal beam or hydrocarbon pumps are installed beneath the rack,
fireproofing shall be provided upto and including the level that is nearest to a 30-foot (9.1
meter) elevation (see Figures 5.3 and 5.4.) Wind or earthquake bracing and non-load bearing
stringer beams that run parallel to piping need not be fireproofed.
c) If air fin-fan coolers are installed on top of a pipe rack, fireproofing shall be used for all vertical
and horizontal support members on all levels of the pipe rack including support members for
the air fin-fan coolers, regardless of their elevation above grade.
d) Fireproofing shall be provided for knee and diagonal bracing that contributes to the support of
vertical loads. Knee or diagonal bracing that is used only for wind or earth-quake loading need
not be fireproofed.
e) Frequently, the layout of piping requires that auxiliary pipe supports be placed outside the main
pipe rack. These supports include small laterals pipe racks, independent stanchions, individual
T columns, and columns with brackets. Whenever these members support piping with a
diameter greater than 6 inches or important piping such as relief lines, blowdown lines, or
pump suction lines from accumulators or towers, fireproofing shall be provided.

f) A fireproofed catch beam or bracket shall be given beneath larger piping (greater than 6
inches) that is supported by exposed steel spring hangers or rods. Sufficient clearance should
be provided between the bracket or beam and the pipe to permit free movement.

5.3.3 Air fin-fan coolers in a fire exposed envelope :

a) Supports of grade level air fin-fan coolers handling liquid hydrocarbons shall be fireproofed.
b) Fireproofing shall be provided for the structural supports of all air-cooled exchangers handling
flammable or combustible liquids at an inlet temperature above their auto ignition or above
o
315 C, whichever is lower.
c) In case of the air-cooled exchangers located above vessels or equipment containing flammable
materials; all the supports located within a 6m – 12 m radius of such vessels or equipment
regardless of their height, shall be fireproofed. (See figure 5.5)
5.3.4 Tower & Vessel Skirts :

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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& GAS INDUSTRY

a) Fire-proofing shall be used for the exterior surfaces of skirts that support tower and vertical
vessels. Consideration should also be given for fireproofing interior surfaces of skirts if there
are flanges or valves inside the skirt. Interior surfaces of skirts need not be fireproofed if there
is only one manway opening through the skirt and its diameter is not greater than 2 feet (0.6
meter). Openings other than the single manway can be closed with removable steel plate at
least 1/4 inch (6.4 millimetres) thick. The effect of draft through vent openings and space that
surrounds pipe penetrations in the skirt should be minimised.
b) Fireproofing shall be used for brackets or lugs that are used to attach vertical reboilers or heat
exchangers to towers or tower skirts.

c)
5.3.5 Leg Supports For Towers & Vessels :
If the towers or vessels are elevated on exposed steel legs; fireproofing the leg supports to their full
load-bearing height shall be used.
5.3.6 Supports for Horizontal Exchangers, Coolers, Condensers, Drums, Receivers and
Accumulators :

Fireproofing should be given for steel saddles that support horizontal heat exchangers, coolers,
condensers, drums, receivers, and accumulators that have a diameter greater than 30 inches (0.76
meter) if the vertical distance between the concrete pier and the shell of the vessel exceeds 18
inches (0.46 meter).
5.3.7 Fired Heaters :
a) Fireproofing shall be used for all supports for fired heaters in hydrocarbon service. Heaters are
often supplied with short, steel legs that are set on reinforced concrete piers. These legs shall
be fireproofed from the concrete piers upto the point where the steel columns are welded to the
steel floor plate of the firebox.
b) If structural supports are provided by horizontal steel beams beneath the firebox of an elevated
heater, fireproofing shall be used for the beams unless at least one flange face is in continuos
contact with the elevated firebox.
c) For common chimneys or stacks handling flue gas from several heaters; structural support for
ducts or breeching between heaters and stacks shall also be fireproofed.
d) When fired heaters in other than hydrocarbon service, such as steam superheaters or catalytic
cracking-unit air heaters, are located within a fire-exposed envelope, fireproofing shall be
provided for their support members if a collapse would result in damage to adjacent
hydrocarbon-processing equipment or piping.
5.3.8 Electrical power and Instrument cables
a) Cables in trays, racks or ducts which are critical (e.g. cables feeding emergency shutdown and
emergency depressuring valves) shall be protected from fire damage, unless they are
designed to fail safe during a fire exposure. Fire proofing requirements of such cables shall be
as per API-2218.
b) The need to protect other electrical, instrument or control systems not associated with control
or mitigation of fire should be based on the risk assessment.
5.3.9 Pneumatic and hydraulic instrument tubing
Pneumatic and hydraulic instrument lines which are critical (e.g. tubing for emergency shutdown
and emergency depressuring valves) shall be protected from fire damage, unless they are
designed to fail safe during a fire exposure. Fire proofing requirements of such lines shall be as per
API-2218.
5.3.10 Emergency valves within a fire exposed envelope
Emergency valves and valve actuators located in a fire exposed envelope meeting the following
criterion shall be fireproofed:
a) The valve is important to shutting down the unit safely.

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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FIRE PROOFING OF STEEL SUPPORTING STRUCTURE IN OIL
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b) The valve is for depressurising the equipment

c) The valve is used for isolating the fuel feeding the fire.

Examples of these valves are isolation valves in piping to pumps that are fed from large towers,
accumulators or feed surge drums.
Fireproofing of such valves shall be done as specified in API-2218.
5.4 FIREPROOFING OUTSIDE PROCESSING UNITS:
5.4.1 Pipe Racks :
a) Fireproofing shall be provided for pipe rack supports outside processing units if they are
located within a fire-exposed envelope. Bracing for earthquakes, wind or surge protection and
stringer beams that run parallel to piping need not be fireproofed.
b) If important pipe racks run within 20-30 feet of open drainage ditches or channels that may
contain oil waste or receive accidental spills, either fireproofing should be considered for the
pipe rack supports as described in (5.3.2 (b)) as above or the ditch should be covered.
5.4.2 Storage Spheres/ Vessels & its Supports :
Fire proofing protects the LPG vessel by reducing the heat input to the vessel and also by controlling
the rate of rise of vessel wall temperature. Fireproofing provides protection in case water supply is
interrupted.
a) Fire proofing of all LPG vessels, their supports and connected/ nearby pipelines shall conform
to the requirements stipulated in OISD-STD-144.
b) Fireproofing shall be provided on the aboveground portion of the vessel’s supporting
structures. The fireproofing shall cover all support members required to support static load of
the full vessel. Fireproofing shall not encase the points at which the supports are welded to the
vessel.

5.4.3 Horizontal Pressurised Storage Tanks :

Horizontal pressurised storage tanks should preferably be installed on reinforced concrete saddles.
Fireproofing shall be given for exposed steel tank supports that are more than 18 inches (0.46 m)
high, measured at the lowest point of the tank shell.

5.4.4 Flare Lines :

Supports of flare lines shall be fireproofed if they are within a fire-exposed envelope or if they are
with in 20-30 ft distance from the open ditches/drainage channels, likely to receive large accidental
spills of hydrocarbons.

6.0 FIRE PROOFING MATERIALS AND SYSTEMS

6.1 General
Passive fire proofing materials & systems should conform to the following parameters:
a) It should fulfil its protection role by limiting the temperature of substrate to be within the
guaranteed maximum temperature over a specified time period.

b) The fire protection should not fail at the end of this specified period, but should continue to offer a
reasonable measure of protection beyond this period.
c) It should have system integrity so that the protection remains in place during a fire, and can
withstand both the thermal stresses and impingement of fire water from hoses/monitors. Test
checks as necessary should be carried out.
d) The fire protection must be non-corrosive to the substrate and be compatible to environmental
conditions. It must not in itself become a hazard in a fire condition whether by spalling,
spreading flame, or producing toxic fumes.

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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e) Selection of the fire proofing system must take into account the weight limitations imposed on the
strength of steel supports to be fireproofed especially for existing installations.
f) The materials should have adequate adhesion, strength and durability.
g) The fire proofing system should be adequate for the desired fire rating.
h) The fire proofing material/coating should be resistant to weather effects such as chalking and
erosion. Top coat, wherever provided, must be resistant to solar ultra violet radiation.
6.2 Fire rating criteria for material selection
The following factors should be considered in selecting the fire rating of the material to be applied:

a) The source volume of leak.

b) The time required to block flows and backflows of fuel that may be released.
c) The time required to apply adequate and reliable cooling water from fixed monitors, fixed water
spray systems, and hand hose lines.
d) The time required for the area’s drainage system to remove a spill.
e) The layout of the equipment, particularly if congestion exists.
f) The physical properties of material that may be spilled.
g) The fuel’s burning rate.
h) The fuel’s heat of combustion.
i) The severity of operating conditions, particularly the temperature if the material being handled is
above its auto ignition point.
j) The importance of the unit to continued plant operations and earnings.
k) Availability & proximity of fire fighting resources in and around the plant and time required for
evacuation of personnel.
Further, the fire rating for LPG storage vessels shall be as per OISD-STD-144 whereas for all other
areas, it should be as per API - 2218.
6.3 Fire Proofing Materials
Materials normally used for fire proofing are
a) Dense cement concrete
b) Light weight concrete
c) Mastic (Intumescent/Subliming) etc.
Prior to use, these materials should be checked to relevant specifications.
6.3.1 Dense cement concrete
Dense cement concrete shall be of grade M20 conforming to IS: 456 or equivalent.
This traditional material has been used for decades as fire proofing. Tough and dense, (approx.
density 2200-2400 Kg/cum) they provide long term protection in most environments.
In areas of high maintenance activity, where fire proofed structures could be subject to impact and
abrasion, concrete fire proofing offers good mechanical resistance.
When applied to columns where water could penetrate between steel and concrete, it shall be
weather proofed with a caulking bead or other approved mastic application.

6.3.2 Lightweight Concrete

This concrete is made of light weight aggregates such as vermiculite, mica, perlite and cements. Dry
densities range from 640 to 960 kg/cum. Lightweight materials are normally sprayed on but they may
be troweled or formed in place using light reinforcing mesh.

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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Insulating concrete, fire proofing cements and plasters made with lightweight or special aggregates,
may be used when weight becomes a limiting factor in the design.
Finished lightweight concrete normally require top coat for weather protection when used in extreme
climates.

6.3.3 Intumescent / Subliming mastic coatings

Intumescent/subliming coatings are used in appropriate applications. Specific attention should be

given to the possibility of a fume or smoke hazard arising from exposure of intumescent coatings to
fire.
Intumescent coatings provide protection by expanding during heating and forming an insulation layer
of char. These materials are durable, light weight and also provide long term corrosion protection to
steel. However, they need stringent surface preparation.
Subliming coatings consist of two components applied with reinforcement. They absorb large amount
of heat in the event of fire and they change directly from solid to gaseous state.
It is important to include mesh reinforcement in these systems for two reasons. Firstly the thermal
expansion characteristics are thereby modified to come nearer that of the steel substrate. Secondly
the mesh holds the coating in place during a fire when it's bond to the primer eventually fails, to
achieve satisfactory protection in jet fires, the thickness of the coating needs to be increased by
reinforcing the same with suitable wire mesh.
Mastic fire proofing materials shall be applied by spraying or troweling. Surface preparation for
application of a paint primer shall be in accordance with manufacturer's recommendations.
Mastic fire proofing materials have a density of approximately 960 to 1290 kg/m3.
Intumescent and subliming mastic coatings shall be sealed in accordance with the manufacturer's
recommendations for possible extreme weather conditions. In locations where there is exposure to
high levels of ultraviolet radiation (from sunlight), premature ageing should be considered.
UV protection can be provided by applying a thin top coat of aliphatic polyurethane.

6.3.4 Specialist Applications

There are certain structures or vessels, which might be subjected to thermal shock conditions.
Refrigerated vessels and furnace burner supports where the burner is integral with the furnace are
some of these. For these types of special applications, composite arrangements of alternate layers of
thermal insulation and a passive fire proofing should be done.

Irregular shapes such as flanges, valves, pipes, cable trays, etc., present difficulties in application
techniques and create conflict with the access requirements for routine maintenance. The problem is
suitably addressed with the availability of other than concrete fireproofing systems including
preformed and/or sculptured sections, designed boxes, etc. Applicability of these systems shall
conform to the necessary requirements mentioned in clause no 7.2.2 of this document.

6.3.5 Asbestos

Fireproofing systems/materials shall not contain asbestos.

7.0 INSTALLATION OF FIREPROOFING SYSTEMS

7.1 General
The standard fireproofing material for all systems is cement concrete. Alternative systems using
proprietary materials herein referred to as ‘other than cement concrete systems’ are also available.
These systems can be preferred for existing structures whose strength or space limitations do not
allow the use of cement concrete.
“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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7.2 Fireproofing systems

7.2.1 Cement concrete fireproofing systems

Dense cement concrete shall be of grade M20 conforming to IS:456 or equivalent. Solid
encasement of the structural member is the usual method of application. (Refer to Annexure V)

In case of application of cement concrete in the operating units, only metallic shuttering shall be
used.

The minimum required thickness of fireproofing cement concrete is 50 mm.

7.2.2 Other than cement concrete fireproofing systems

Other than concrete fireproofing systems should meet the following requirements:

a.) It shall be asbestos free;

b.) System provider should furnish test results carried out by independent laboratories
demonstrating that the system is adequate for the proposed application and its thickness shall
have the required resistance against hydrocarbon fires;

c.) It should be reliable in service and should provide desired life-span with reasonable
maintenance, taking into account all possible variations in ambient temperature and humidity;

d.) When exposed to damp conditions, the system should not initiate or sustain any long-term
pernicious effects, such as corrosion of the painted steel work.

e.) Installation of the system shall be carried out by specialists, strictly as per the approved
procedures of the manufacturer.

7.3 Preparation for fireproofing

The entire steel surface to be fireproofed should be cleared of all loose dirt, oil and grease etc for
better adhesion of the fireproofing to the steel.
All the steel members, new as well as existing ones; which need to be fireproofed should be suitably
primed for corrosion protection.
The primer should be compatible with the fireproofing to be applied.
Mesh reinforcement type, fixing and overlaps etc. shall be as per the manufacturer’s
recommendations.
7.4 Installation of fireproofing
All the other than concrete fireproofing systems shall be applied in accordance with the instructions
of the manufacturer.
For concrete surfaces weatherproofing is not needed, however, for proprietary systems, a flexible
membrane may be required as per the prevailing local circumstances.
Joints between exposed steel work and fireproofing should be caulked to prevent water from
entering the system at this point.
The top of fireproofing should be protected by cover plates continuously welded to the steel
structure in order to prevent ingress of rainwater between the members and the fireproofing. Typical
details of cover plates are given in ANNEXURE- VI.
During the course of application of fireproofing, proper care should be taken to protect the surface
from heavy rain, frost and extreme weather conditions etc.

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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Fireproofing shall not be carried out when the ambient air temperature and/or the temperature of the
surface to be fireproofed is 10-Deg C or below.
Provision should be made for adequate ventilation during and after application, until the materials
are dry. However, in extremely dry and hot conditions, appropriate measures should be taken to
keep vermiculite-containing systems moist until set.
The fireproofing should be resistant to frost damage after its proper setting, wherever necessary.
Approved welding procedure by a competent authority should be followed if the fixing of such
systems to surfaces necessitates the welding of certain fixtures to the surfaces.

8.0 METHODS OF APPLICATION OF FIRE PROOFING

8.1 General
The process of fire proofing application consists of but not limited to, attaching pins for retention of
metal/fabric mesh reinforcement, abrasive blasting where required, priming with appropriate and
approved primer system, installation of reinforcing mesh, masking where necessary, mixing,
spraying, trowelling and levelling, rolling top coating if required, and demasking.
8.2 Qualification of applicators

The application shall be performed by qualified applicator having training, equipment and
experience. Supervisory or lead personnel involved with the application shall be or have been
trained by the manufacturer of fire proof coating material and its application. Applicator shall submit
written verification of such training in case of proprietary products.

8.3 Safety precautions

The applicator shall follow standard industrial hygiene practices for the handling of chemical
coatings and shall confirm to applicable codes of practice and regulations. Necessary Personal
Protective Equipment as detailed in OISD-STD-155 should be used.
8.4 Storage of material
Materials should be stored at site in accordance with the manufacturer’s recommendations, since
some materials are temperature sensitive and others must remain upright in their containers for the
proper sealing. Material should not be used if its shelf life has exceeded.

8.5 Sample preparation

Prior to actual production work, a sample area will be coated with fire proof coating following all
pertinent procedures and specifications. This sample should be typical of the work to be done.
This sample or sample area will then be approved by the Client's Representative, Applicator's
Representative, Consultant's representative and any other party as defined and required by the
contract, for quality of surface finish and adherence to procedures.

8.6 Work start-up

Applicator will obtain a release from the Client for a given area to start on.
8.7 Environmental conditions
Environmental conditions are important for every aspect of the Application System.
Environmental conditions/ specifications for blasting where required and priming are as per
manufacturer or relevant standard, which include but are not limited to ambient temperature,
substrate temperature, relative humidity and dew point. Environmental conditions/ specifications for
the system provided by the manufacturer of fire proof coating, these conditions shall be recorded for
each system since conditions can vary considerably depending on location. Environmental
conditions should be recorded daily. Where water is required to be added, it should be clean,
potable and of a quality suitable for use in blending with fireproofing coatings.

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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8.8 Application details for specific fire proofing materials

8.8.1 Dense Cement Concrete

The entire steel surface to be fireproofed shall be cleared of all loose dirt, oil and grease etc for
better adhesion of the concrete to the steel.
A typical composition of dense cement concrete should be M20 as per IS: 456 with gravel size as
passing through 10 mm sieve.
Dense concrete can be formed in place to the required thickness using steel reinforcement.
In the case of gunniting (pneumatical application) the ratio of the mix shall be one part of cement
and four parts of sand. Cement, sand and water quality shall be as per IS: 456.
8.8.2 Lightweight concrete
A) Substrate preparation
Prior to the application of fireproof coating, structural steel should be suitably primed after
appropriate surface preparation.
B) Mesh retaining pins
Pins should be fixed to the structural substrate at maximum 400 mm centres on a staggered pitch.
Stud fixing may necessitate local removal of the priming system, which should be reinstated to the
original paint specification after the fixing of pins. Welding need not be done for fixing pins on
pressure vessels as the same can be fixed using other techniques.
C) Mesh reinforcement
Reinforcing mesh (made of GI/SS) should be attached to previously installed pins using suitable
arrangements.
The mesh should be pulled away from the substrate so as to lie substantially within the centre of the
final fireproof coating thickness.
Mesh shall be overlapped at all joints and no more than three mesh thicknesses are permitted at
any one joint. Cut ends may be twisted together to make a more secure joint. Alternatively,
galvanised wire ties at 150 mm centres may be used.
For pressure vessels where pins are not permitted, reinforcing mesh should be attached to a system
of floating rings and tensioning wires to construct a monolithic reinforcement.
D) Fireproof coating
The light weight concrete shall be mixed in accordance with the Manufacturer's Instructions for
application and spray applied in the minimum number of coats or by using trowel to the required
thickness as per Manufacturer's recommendation. The coating should generally be float finished to
close down the texture.

E) Water shedding
Where water-shedding cowls are not provided, top surfaces and all terminations of fire proof coating
against steel must be sloped and floated to shed water.
A `U' shape shall be cut at the concrete steel junction to receive mastic sealant.
F) Top Coating - Weather Barrier
After the concrete coating has been allowed to cure and dry for at least five days, suitable top coat
as recommended by manufacturer may be applied, if required.
G) Sealing of concrete Coating/Steel junctions
Suitable flexible sealant e.g. Polysulphide based or Silicone rubber based should be applied in the
groove.

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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All sealants must be suitable for use with a concrete mixture and be weather resistant and remain
flexible.
8.8.3 Mastics
A) Mesh retaining pins
Pin Installation wherever required, shall be done in accordance with the procedure outlined in the
Manufacturer's Application Manual. Embedded mesh reinforcement shall be used based on
manufacturers’ recommendation.
B) Substrate preparation
Substrate preparation shall be done in accordance with product requirements. The blast
finish/profile shall be accepted prior to priming.
C) Priming procedure
Priming of substrate shall be done in accordance with paint manufacturer’s application guideline.
The primers approved by material manufacturers only shall be used.
D) Mesh reinforcement
Meshing of substrate shall be done in accordance with the procedures outlined by mastic material
manufacturer’s application manual.
E) Masking
Any surfaces or equipment in the spraying areas which do not receive mastic must be masked off,
using polyethylene or equivalent. Regardless of the structural configuration being worked on,
overspray is always a concern.
F) Intumescent/Subliming coating
Solvent based or Solventless application of Intumescent / Subliming Materials shall be done in
accordance with the procedure outlined by the Intumescent/ Subliming Materials Manufacturers
Application Manual upto the required thickness.
G) Surface finish and inspection
Surface finish is a visual standard for sprayed Intumescent/Subliming Material, which includes
various structural configurations. Visual inspection should be performed to ensure that there is no
exposed mesh, debonding at terminations or bubbles below the finish surface layer.
Physical inspection would consist of drilling holes in the Intumescent/ Subliming Material to
determine actual thickness, tapping with a hammer to detect possible hollow areas or delamination
between sprayed layers of coating not visible.

9.0 QUALITY CONTROL IN APPLICATION OF FIRE PROOFING

9.1 Introduction
Quality control during application is of prime importance. Satisfactory performance of the
fireproofing material over its expected lifetime depends on the user’s and the applicator’s knowledge
of materials and application techniques and on continuous inspection by qualified plant personnel.
Attention to the following points will ensure a quality job:
9.1.1 Qualified personnel
Both the user and the applicator should have a detailed knowledge of the characteristics of the
fireproofing material and the application techniques that are necessary to achieve the desired
degree of fire resistance. The applicator should be qualified as per Clause no 8.2

9.1.2 Mock-up application

The contractor/applicator is required to provide a sample of the finished work so that there is no
misunderstanding about the desired texture, smoothness and soundness of the finished coating.
Before start of the application job, mock-up application should be carried out over 1Mx1M surface
area to ascertain the skill of the applicator.
9.1.3 Surface preparation
“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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Substrate surfaces must be cleaned so that they are free from oil, grease, liquid contaminants, rust,
scale and dust. If a primer is required, it must be compatible with the fire proofing material.
9.1.4 Application
It is to be ensured that the materials must be applied in accordance with the manufacturer’s
recommendations for dry thickness and use of reinforcing materials. Thickness of material must be
ensured as some of the mastic coating shrinks as much as 30 per cent when cured.

9.1.5 Curing
Some materials require a controlled curing period to develop full strength and prevent serious
cracking in the future. Hence, proper curing is to be ensured.
9.1.6 Random core sample check
Random core samples should be taken after application to verify coat thickness, proper bonding,
and voids. Defects, if any, should be rectified properly.
9.1.7 Supervision
Fire proofing shall be supervised by competent personnel having appropriate knowledge and
experience backed with test results. These persons shall inspect the process at its various stages
and maintain an inspection check list for stage wise approvals of the same. Following minimum
stages shall be included in the inspection check list
i) The condition of the steel surface to be fire proofed.
ii) The quality and placing of the reinforcement mesh.
iii) The quality and application of fire proofing material.
iv) The joints between fire proofing and the steel work which are exposed to weather.
v) Weatherproofing.

10.0 PERIODIC INSPECTION AND MAINTENANCE

10.1 Deterioration during service life
As fireproofing materials age, problems can develop that affect the usefulness of the coating and
weaken the protected structural supports.
Any fireproofing material is subject to a certain amount of degradation over time. However, some
applications have been known to fail completely at a rapid rate. Some failure may be caused by
materials that are improperly selected but in most cases the failure results from poor applications.
Cracking or bulging of the surface of the material is the first sign of a problem. If the problem is not
corrected, moisture, chemicals, corrosive vapour, and marine condensation can enter and lead to
corrosion of both the substrate and the reinforcement materials.
Weathering or the use of the wrong top coat can cause the fireproofing to become permeable to
moisture and vapour. This permeability can lead to serious corrosion and deterioration.
Loss of bonding to the substrate seriously affects the material’s performance and may be caused by
moisture penetration, corrosion, the use of an improper primer on the substrate, or poor preparation
of the substrate before the fireproofing is applied.
The weathering effects of sunlight and chemical environment have been known to affect some
mastic materials to the extent that they lose a significant amount of their insulating ability due to
development of cracks, disbonding, and peeling off top coat.
10.2 Inspection
To reduce the risk of structural failure from hidden corrosion or the risk from fire because of
fireproofing loosened or damaged by underlying corrosion, all fireproofed surfaces should
periodically be inspected and tested as per schedule prepared by the owner based on local
environmental conditions and criticality of the equipment. An inspection and testing program should
include the following steps:
a) Survey the coating for surface cracking.
“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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b) Selectively remove small sections of fireproofing to examine conditions at the face of the substrate
and the surface of reinforcing wire.
c) Visually check for the loss of fireproofing materials as a result of mechanical abuse.
d) When the fireproofing material is applied, coat and set aside several pieces of structural steel for
periodic fire testing over the expected life of the coating.
In the event of a fire, the affected area of coating should be thoroughly examined; including
substrate if required and necessary repairs should be carried out.
10.3 Maintenance
Maintenance of fire proof coatings should be done in as under:
a) When cracks are wider than hairline, the opening should be cleaned out and filled with new
material according to the manufacturer’s instructions.
b) If top coat is required to prevent moisture from penetrating, it must be renewed at intervals
recommended by the manufacturer.
c) Loss of bonding to the substrate may be noticed when the surface bulges or if an abnormal
sound is given off when the surface is tapped with a light hammer. In areas that have evidence
of bond failure, fireproofing should be removed, and the substrate should be thoroughly cleaned
and properly primed before new material is applied.
d) Whenever rust stains are observed on the external surface of fire proof coating, the integrity of
coating as well as the condition of substrate should be established by chipping the affected
area.

11.0 REFERENCES

i) UL- 263 : Fire tests of Building Construction and materials

ii) UL-Subject 1709 : Structural steel Protected for Resistance to Rapid Temperature rise fires

iii) ASTM E119 : Method for fire test of building construction and Material

iv) ASTM –E1529 : Standard test methods for determining effects of large Hydrocarbon pool fires
on Structural members and assemblies.

v) API 2218 : Fireproofing Practices in Petroleum and Petrochemical Processing plants

vi) API- 2510 : Design and construction of LPG installations

vii) API-2510A : Fire-Protection consideration for the design and operation of LPG storage
facilities

viii) OISD-STD-144 Vol. IV : Safety and Fire protection in LPG Bottling Plant operations

ix) OISD-STD-155 Part I & II : Personnel Protective Equipment.

x) IS : 456 : Plain and Reinforced Concrete - Code of Practice

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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ANNEXURE- I

FIRE SCENERIOS AND FIREPROOFING

Pool and jet fires

In a hydrocarbon industry the leaks from various potential sources of leakage (PSL) e.g. small bore
connections on piping and equipment, flange joints, pump mechanical seals, expansion joints etc
under different ambient conditions and the type of product handled; can form a liquid pool or be
dispersed as either an aerosol liquid cloud or as a vapour cloud. Ignition of these leaked products
shall either result in a pool fire or a torch fire. These fires continue to sustain till the source feeding
these leaks is completely stopped.

It is observed that liquid pools are normally formed by all hydrocarbon products containing Pentane
and also butanes/butenes at sub zero ambient temperatures. Further it is also seen that
refrigerated/cryogenic liquefied gases may form liquid pools in case of their accidental release while
they are handled at or near their atmospheric boiling points. Particularly this may happen during a
prolonged release of these gases, when the vapourization rate caused by heat pick-up from the
surroundings does not match the rate of release. Pool fires possibilities shall be taken into account
for above categories.

As the pressurized liquefied gases disperse in the form of an aerosol liquid jet or as a vapour jet
upon their accidental release, they shall not result in pool fires. Similarly vapour release shall also
disperse as a jet. Hence, ignition of an aerosol liquid jet or a vapour jet shall lead to a torch fire
which may cause impinging flames with high radiation intensities The length and width of jet flames
is dependent on factors like size of the hole, wind speed and direction and the pressure at the
upstream of the leakage point.

Maximum efforts should be made to protect the supporting steel structures from torch fires by
proper location selection and orientation of the supporting structure with regard to PSL and/or by
providing fire shields near the PSLs or the surfaces of the structures to avoid direct impingement. If
the supporting structures protection against torch fires is not possible or practicable then fire
proofing of these structures should be done as per the relevant fire exposed envelope.

For the most part, liquid and gaseous hydrocarbon fires are characterized by highly luminous flames
resulting from hot carbon particles (soot).Because of limited mixing with oxygen, combustion gases
are fuel-rich and produce nearly continuous radiation in the infrared region making the hot gas and
soot particles behave as a grey body radiator. Petrochemical fire temperatures reach as high as
130deg C (240Deg. F) but average 100deg C (185deg F) because of various factors including
radiational cooling of the fire ball, winds and geometry. Free burning fires normally do not achieve
the theoretical combustion temperatures for the fuels involved. During fires with high pressure fuel
sources, convection plays a larger role and can even be the primary mode of heat transfer. Jet fires
are characterized by high convective inputs.

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”
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Annexure II (Page1 of 2)

TESTING OF FIRE PROOFING MATERIALS

Fire resistance testing is one of the very important steps in assessing the fireproofing rating of any
material prior to its use for fireproofing purpose. No fire test method can be termed to be typical of a
real fire situation and so, there is no single correct or best fire test method. Standardized testing
simply provides a frame of reference for relative comparisons of fireproofing materials and designs.
In the 70s, ASTM E119 Fire Test of Building Construction Materials was the only internationally
accepted standard for investigating the performance of fireproofing materials. This test method,
however, was designed to measure the fire performance of walls, columns, floors, and other
building members in solid fuel fire exposures. It does not simulate the high intensity of liquid
hydrocarbon-fuelled fires. The slope of the time/temperature heating curve for the typical solid fuel
fire is significantly different than that of the more instantaneous and intense liquid hydrocarbon fire.
Wood, for example, burns fairly slowly. Volatilization of the fuel from the surface is slow and wood
can form a char which provides some protection. Liquid hydrocarbons volatilize quickly to feed a
fire, and there is no protective char formation. In recognition of this, several of the major oil
companies developed their own outdoor hydrocarbon pool fire tests. These tests were more
representative of the threat posed to refineries and petrochemical plants but reproducibility was not
very good.

UL 1709 Rapid Rise Fire Tests of Protection Materials for Structural Steel and ASTM E1529
Standard Test Methods for Determining Effects of Large Hydrocarbon Pool Fires on Structural
Members and Assemblies were first issued in the early 90s. Both tests involve a test furnace which
develops an average temperature of 2000F (1093C) within the first 5 minutes of the test. The
principal difference is that UL 1709 involves a total heat flux of 65,000 BTU/ft2-hr (205 kW/m2),
whereas the ASTM E1529 heat flux is 50,000 BTU/ft2-hr (158 kW/m2). Temperature is an important
parameter but heat flux is considered as a better measure of the amount of heat stress being placed
on a material (how fast heat works on a material). Although the temperature is the same, the higher
heat flux of UL 1709 makes it a more severe test. A comparison of standardized fireproofing test
procedures is placed in tabular form as below

Fireproofing test UL1709 ASTM E1529 ASTM E 119

Standards UL 263

Testing environment Rapid rise fires Effects of large Structural material

Exterior Hydrocarbon pool for building
Petrochemicals fires on exterior interiors
Structural members

.
Heat flux in BTU/ft2-hr

After

Five Minutes 65000 ( 5000) 50000( 2500) (11000)*

One Hour (37400)*

Temperature after

Three minutes > 15000F

Five minutes 2000±2000F 2000±1500F 10000F
Thirty Minutes 2000±2000F 2000±1500F 15500F
One hour 2000±2000F 2000±1500F
18500F
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Four hours 2000±2000F 2000±1500F 20000F

Eight hours 2000±2000F 2000±1500F 23000F

* Heat flux is neither specified nor measured in ASTM E 119. Data listed above are from a
Major Test Methods E 11furnace as reported in the Appendix of ASTM E 1529-93, section XI. 2.2.

Annexure-II (Page 2 of 2)

BRIEF DESCRIPTION ABOUT UL 1709 TESTING METHOD

There are a number of fire test laboratories in North America and Europe (For partial directory refer
Annexure III). These laboratories conduct fire tests according to defined standards and depending
upon performance, a rating is determined for the particular type of test run. A rating is given in time
units with temperature limits imposed on the protected part of the test assembly. Annexure - IV list
some of the important ratings used in the Hydrocarbon processing industries for structural and
personnel protection of stationary materials.

The oldest and most widely used independent testing organization is Underwriters Laboratories, Inc.
(ULI) in USA.ULI provides fire test and manufacturing follow-up services for many products on a
non-profit basis. ULI was the first testing organization to standardize the high rise fire test as UL
1709 and offer it as one of their services. Other testing laboratories now conduct similar tests.

In the case of the UL 1709 test, the furnace temperature is brought up to 1093deg C (2000deg F)
within 5 minutes and held within a tolerance of this level for the duration of the test. Tests are
usually run on a light column designated as a W10X49, but they can be run on lighter or heavier
sections. Less material is required to protect heavier members, so the user should be careful to
determine which member was tested. Steel temperatures are measured beneath the protective
material at 4 levels with 3 thermocouples per level. Failure criteria for columns are:

When the average of all thermocouples at any level reaches 538 deg C (1000deg F) or;

If any individual thermocouple reaches 649 deg C (1200deg F).

Environmentally exposed materials are tested against control material to determine the effect on
fireproofing performance. A loss in performance of 25% or more in any of these tests prevents a
material from receiving an external use rating. Even though these evaluations are helpful in
determining material suitability for industrial use, the aging tests are accelerated and small losses in
performance may turn into significantly larger ones over long periods of time. However, this test
program is an important tool in rating and monitoring potential fire protection materials for outdoor
use.

After successful completion of the test, a listing or rating is offered, which in the case of ULI, is
printed in an annual Fire Resistance Index under X or XR classifications for columns for the hourly
period tested. Listings in the X classification are for designs tested to the ASTM E-119 cellulosic fire
environment whereas those in the XR classification have been tested to the UL 1709 high intensity
fire environment. XR ratings (listings) include mandatory additional testing for environmental aging
such as freeze thaw cycling, salt fog, high humidity, and SO2 / CO2 exposures. For X
classifications, environmental testing is optional.

While, UL -1709 is the minimum requirement for a fire proofing material, materials being used for
pressurized storage vessels must have preferably undergone independent tests successfully on
such type of vessels.

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from the use of OISD Standards/Guidelines.”
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ANNEXURE - III

PARTIAL DIRECTORY OF FIRE TEST LABORATORIES

Name of the laboratory/Institute Location

Federal Institute for Material Berlin, Germany
Research and Testing (BAM)
Factory Mutual Research Norwood, MA, USA
Corpn,(FM)
Loss Prevention Council (LPC) Borehamwood, Herts,
England.
Southwest Research Institute San Antonio,TX, USA
(SWRI)
TNO Delft, Netherlands

Underwriters Laboratories Northbrook, IL, USA

Inc.(ULI)
Warrington Fire Research Center Warrington, Cheshire,
England.
Health & Safety Executive Buxton

U. S. Department of USA
Transportation (DOT)

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from the use of OISD Standards/Guidelines.”
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ANNEXURE - IV

TEST RATINGS - STRUCTURAL STEEL FOR OIL INDUSTRY

(STATIONERY MATERIALS)

RATING NORMAL TEST ENVIRON- CRITERIA TO BE TEST TYPE

CONFIG- MENTAL TEMP. MET
RATION

UL 1709 W 10 X49 1093 deg C (2000 Protected steel High intensity or high
Column 9” deg F) must not exceed rise fire curve. Gas
high 538 deg C (1000 fired furnace
deg F)
BAM 90 min. for Horizontal 600-900 deg C 250 deg C (482 Pressurised Propane
pressurised 485 M3 Tank (1112 - 1652 deg deg F) maximum jets in a series
LPG tanks with 6.4 mm F) wall temperature surrounding the tank.
(Germany) wall thickness measured in the
and 50% ullage space not
filled with adjacent to the
Propane liquid. maximum
internal pressure
of approximately
20 bars.
GESIP (France) Loaded 1000 deg C Protected steel Simulated
vessel + + must not exceed Pool fine furnace test
Flame 1100 deg C 427 deg C (800 H/C
impingement deg F)
and + Hose
Stream
H.S.E. Loaded Pool fire (H/S) 427 deg C Pool fire
(U.K.) vessel 1100 deg
C

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from the use of OISD Standards/Guidelines.”
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ANNEXURE V
TYPICAL DETAILS - CONCRETE FIREPROOFING - SOLID ENCASEMENT

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ANNEXURE VI
TYPICAL DETAILS - COVER PLATES FOR WEATHER PROTECTION

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from the use of OISD Standards/Guidelines.”
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from the use of OISD Standards/Guidelines.”
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PIPES

Figure 5.3 : Pipe rack without pumps in a Fire Exposed area

Note : shows Fire proofed Structures

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from the use of OISD Standards/Guidelines.”
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Fire Exposed
Envelope

Hydrocarbon Pumps

Figure No. 5.4 : Pipe racks with large Fire-Potential Pumps installed below

Note : shows Fire Proofed Structures

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from the use of OISD Standards/Guidelines.”
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Fin-fan air cooler Fin-fan air cooler

Stinger beams
supporting vertical
No fireproofing on stinger loads to be
beams which do not fireproofed.
support vertical loads

Fireproofing

Figure 5.5 - Pipe rack supporting air fin-fan coolers in a fire exposed envelope.

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from the use of OISD Standards/Guidelines.”
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Fireproofing

Non fire potential

equipment

Fire potential
equipment
Floor on which
liquids can
accumulate.
Fire exposed
envelope

Non load bearing bracings

not to be fireproofed

Figure 5.6 : Structures supporting fire potential and non fire potential equipment in a fire exposed envelope

“OISD hereby expressly disclaims any liability or responsibility for loss or damage resulting
from the use of OISD Standards/Guidelines.”