American Water Works Association

ANWAWVVA D120-84 (R89)

(First Edition)
Reaffirmed without revision 1989

AWWA STANDARD
FOR

THERMOSETTING FIBERGLASS-
REINFORCED PLASTIC TANKS

Reaffirmed without reivison June 18, 1989.

Reaffirmation approved by American National Standards Institute Inc., Nov. 3, 1989.

First edition approved by AWWA Board of Directors Jan. 30, 1984.

Approved by Amzrican National Standards Institute Inc., Jan. 24, 1984.

AMERICAN WATER WORKS ASSOCIATION

6666 West Quincy Avenue, Denver, Colorado 80235

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 Committee Personnel

The AWWA Standards Committee on Thermosetting Fiberglass-Reinforced

Plastic Tanks, which developed and approved this standard, had the following
personnel at the time of approval:

CHARLES R. MEEK, Chairman

Consumer Members

W. F. GUI LLAUME, Connecticut Water Company, Clinton,

Corm. (NEWWA)
R. P. MCHUGH,* New Haven Water Company, New Haven,
Corm. (NEWWA)
G. A. RUSSELL, Northern Illinois Water Corporation,
Champaign, 111. (AWWA)
W. E. STRAWMAN, Public Utilities Bureau, Akron, Ohio (AWWA)
J. F. WANDYEZ, Erie County Water Authority, Buffalo, N.Y. (AWWA)

General lntere.st Members

C. H. ANCELL, C.H. Angell & Associates, Inc., Glencoe, 111. (AWWA)

C. R. MEEK, CH2M Hill, Corvallis, Ore. (AWWA)
G. R. MEIGS, Straam Engineers, Portland, Ore. (AWWA)
W. B. SINNOTT, Hazen & Sawyer, New York, N.Y. (AWWA)
H. A. TUTTLE, Hiram A. Tuttle & Associates, Coventry, Corm. (AWWA)

Producer Members

R. D. BRADY, Ershig’s Inc., Bellingham, Wash. (sPI)

B. R. DARRAH, The Society of the Plastics Industry of
Canada, Don Mills, Ont~ (sPI-c)
N. J. KRAUS, Owens-Corning Fiberglass Corporation, Toledo,
Ohio (sPI)
L. E. PEARSON,* Owens-Corning Fiberglass Corporation,
Conroe, Texas (sPI)

*Alternate

Copyright @ 1984 by American Water Works Association

Printed in USA

ii

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 Table of Contents

SEC PAGE SFC PAGE

Foreword 5 Retest
5.1 Retest . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1. History of Standard . . . . . . .......... iv
11. Information Regarding Use of 6 Marking
This Standard . . . . . . . . . .......... iv 6.1 Manufacture and Service
111. information to resupplied Identification . . . . . . . . . . . . . . . . . . . 13
by Purchaser . . . . . . . . . . .......... v 7 Shipping and Handling
IV. Information to resupplied 7.1 Shipping . . . . . . . . . . . . . . . . . . . . . . . . . 13
by Manufacturer . . . . . . .......... v 7.2 Handling . . . . . . . . . . . . . . . . . . . . . . . . . 13
Standard
Appendix
1 General
1.1 Scope . . . . . . . . . . . . . . . . . . . .. . . .. . . . A Expression of Hoop Tensile
1.2 Classification . . . . . . . . . . . . .. . . .. . . . Modulus ofaf-aminate ........... 15
1.3 Definitions . . . . . . . . . . . . . . .. . . .. . . . B Explanatory Notes to D120-84 . . . . . . . 16
1,4 References . . . . . . . . . . . . . . . .. . . .. . . .
1.5 inspection and Testing Tables
by Purchaser . . . . . . . . . ........... 2
I Requirements for Typel
1.6 Tests . . . . . . . . . . . . . . . . . ........... 3
Contact-Molded Reinforced-
1.7 Affidavit of Compliance . ........... 3 PolyesterLaminates .......... .... 5
2 Materials 2 Minimum Widths of
2.1 Resin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Overlayed Joints . . . . . . . . . . . . . .... 7
2.2 Reinforcing Material . . . . . . . . . . . . . . . 3 3 Pipe for Nozzle Assembly . . . . . . . .... 8
2.3 Surfacing Materials . . . . . . . . . . . . . . . . 4 4 Minimum Flange Thickness for
3 Requirements Reinforced Polyester Nozzles . . .... 8
3.1 General Requirements ... . .... . ... . . 4 5 Shear Bond Area—Nozzles . . . . . . .... 10
3.2 Physical Properties . . . ... . .... . ... . . 4
3.3 Chemical Properties . . ... . .... . ... . . 5 Figures
3.4 Construction . . . . . . . . ... . .... . ... . . 5 1 Flanged Nozzle . . . . . . . . . . . . . . ...... 9
4 Testing Methods 2 Reinforcement of Cut Tank
4.1 Physical Properties . . . . . . . . . . . . ..... 10 Wall for Nozzle Attachment . ...... 9
4.2 Hardness . . . . . . . . . . . . . . . . . . . . ..... II 3 Installed Nozzle (With
4.3 Chemical Resistance . . . . . . . . . . ..... 11 Pipe Penetration) . . . . . . . . . . ...... 10
4.4 Surface Burning Characteristics . ..... 12 4 Installed Nozzle (Without
4.5 Hydrostatic Testing . . . . . . . . . . . ..... 12 Pipe Penetration) . . . . . . . . . . ...... 10

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 Foreword

Thi.~,fi)revtord i.~,fi)rinfi)rmation onl~ and is not a part of A W WA D120.

1. History of Standard evolved, and man y of t hese were available

In June 1971, the Engineering and to the committee.
Construction Committee, appointed by In addition, applicable standards, speci-
the AWWA Technical and Professional fications, and test methods published by
Council, evaluated the use of reinforced the American Society for Testing and
plastics in the water utility industry and Materials (ASTM) and the US Depart-
found sufficient use of products made ment of Commerce were reviewed by the
from this material to recommend the committee. There were two documents
development of AWWA standards. One the committee used as the basis for the
of the most extensive uses of the reinforced AWWA Standard: (1) ASTM D3299,
plastics was for the construction of tanks. Specification for Filament-Wound Glass-
At the 1974 fall meeting, the AW WA Fiber-Reinforced Thermoset Resin
Standards Council approved the forma- Chemical-Resistant Tanks, and (2) Na-
tion of a committee for the preparation of tional Bureau of Standards Voluntary
an AWWA standard for reinforced plastic Product Standard PS-15, Custom Con-
tanks for the water utility industry. tact-M olded Reinforced Polyester Chemi-
The standards committee began the cal-Resistant Process Equipment.
preparation of the new standard early in The initial draft of the proposed
1975. The responses to a questionnaire AWWA standard was prepared and cir-
sent out by the Engineering and Construc- culated to the committee members in
tion Committee indicated that the 1976. After carefully considering the
methods being followed for specifying comments and suggestions received from
and purchasing reinforced plastic products this circulation, the process was repeated
varied within the water utility industry. with revised drafts of the standard in 1977
Frequently it was the practice for the and 1978. Each revised draft was reviewed
water utilities that were planning on using and further revised by the committee until
reinforced plastic products to state the a practical and useful standard had been
actual or anticipated service conditions, developed. The final draft was submitted
and the manufacturer then warranted the to the committee for letter ballot voting
product for that service. In other on Apr. 15, 1983, and a consensus for
instances, the manufacturer presented a acceptance was received.
product for a particular type and condi-
tion of service, and the water utility then Il. Information Regarding Use of
made the selection based on this presenta- This Standard
tion. Because of these practices, functional The purpose of this standard is to
and product-design specifications used by establish the significant quality require-
both water utilities and tank fabricators ments for commercially-available thermo-

iv

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 PLASTIC TANKS v

setting fiberglass-reinforced plastic tanks 9. Whether certified drawings are to

for use in the water utility industry. This be furnished (Sec. IV, Foreword).
standard is based on the technology for 10. Whether plant inspection is re-
the fabrication of the tanks by either the quired (Sec. 1.5).
contact-mold or filament-wound process. 11. ‘Tests to be performed by the
It is intended that the tanks are to be used manufacturer (Sec. 1.6).
for the storage of water and other liquids. 12. Specimens to be provided by the
However, the specific application must manufacturer (Sec. 1.6.4).
consider the limitations as specified under 13. Whether an affidavit of compli-
Sec. 1.1. and information must be pro- ance is to be furnished (Sec. 1.7).
vided by the user to completely describe 14. Whether ultraviolet absorbers are
the tank requirements. Section 111,Fore- to be omitted (Sec. 2.1. 1.2).
word, summarizes supplemental informa- 15. Whether fire-retardant agents are
tion that should be considered. The to be added (Sec. 2.1. 1.4).
purchaser should review this information 16. Color and aesthetic treatment
and other appropriate data and make sequence (Sec. 2.3.1, Sec. 3.1.1, and Sec.
provisions in the supplemental specifica- 3.4.1.1).
tions to describe the specific service 17. Loading conditions (i.e., seismic
requirements. loads, snow loads, wind loads) and design
criteria tank must meet (Appendix B,
Ill. Information to be Supplied by notes to Sec. 3.2.1. 1).
Purchaser 18. Whether outside surface is to be
pigmented, painted, or dyed (Sec. 3.4.2.4).
In placing orders for thermosetting 19. Flange gaskets (Sec. 3.4.5).
fiberglass-reinforced plastic tanks to be 20. Location of lifting or hold down
manufactured in accordance with this lugs (Sec. 3.4.7 and Sec. 3.4.8).
standard, the purchaser, in its supple- 21. Test temperature for laminate
mentary specifications, should include chemical resistance (Sec. 4.3. 1.2).
the following information: 22. Retest agreement (Sec. 5. 1).
1. Standard used—that is, AWWA
D 120, Thermosetting Fiberglass-Rein- IV. Information to be Supplied by
Manufacturer
forced Plastic Tanks..
2. Capacity. When required, the manufacturer or its
3. Material to be stored in the tank. representative shall submit, for approval
4. Height, width, and weight limita- by the purchaser, certified drawings
tions. showing the principal dimensions, con-
5. Temperature conditions. struction details, and materials used for
6. Fittings and attachments to be the fabrication. All work shall be done in
provided, and their description. accordance with these certified drawings
7. Type of installation. after they have been approved by the
8. Oueratimz conditions. ~urchaser.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 This page intentionally blank.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 A\
(,) American Water

AN SVAWWA D1 20-84
Works Assoclatlon

(First Edition)

A W WA Standard for
Thermosetting Fiberglass-Reinforced
Plastic Tanks

Section 1—General

Sec. 1.1 Scope 1.2.2 Grade. Grade 1—fiberglass-

reinforced polyester resin; grade 2—raw
This standard covers the composition,
materials other than grade 1.
performance requirements, construction
practices and workmanship, design, and Sec. 1.3 Definitions
methods of testing thermosetting fiber-
Unless otherwise indicated, the plastics
glass-reinforced plastic tanks for the
terminology used in this standard is in
storage of water and other liquids.
accordance with ASTM D883, Defini-
1.1.1 Limit OJ standard. This stan- tions of Terms Relating to Plastics. In this
dard is limited to atmospheric pressure, standard, the following definitions shall
vented, vertical, above-ground cylinder also apply:
tanks. 1.3.1 Con[act molded: A method
1.1.2 Temperature limits. The nomi- of manufacture whereby a laminate of
nal maximum service temperature is fiberglass reinforcement and resin is built
180° F (82° C). up either by hand or by the use ofa special
1.1.3 Service /irni/.~. “ The exact resin spray gun that directs short fibers and
and reinforcement combination, for use catalyzed resin onto the mold surface.
with specific chemical and structural 1.3.2 Contractor: The person, firm,
conditions, should be evaluated as a or co~poration executing the contract or
laminate by test or by previous service to agreement with the purchaser to furnish a
be suitable for the environment. thermosetting fiberglass-reinforced plastic
tank according to this standard.
Sec. 1.2 Classification 1.3.3 Fi[anlen[ ~~’ound: A method
This standard covers the fabrication of of manufacture whereby a continuous
thermosetting fiberglass-reinforced plastic fiberglass-strand reinforcement, together
tanks defined by method of manufacture with resin, is placed in a predetermined
(type) and raw materials used in the pattern onto a suitable mandrel until
construction (grade). sufficient layers have been applied to
1.2.1 T)’pe. Type I—contact mold- form a laminate.
ed; type n-filament wound. (See note in 1.3.4 Head: The end closure of
Appendix B.) cylindrical fiberglass-reinforced tanks;

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
2 AWWA D120-84

may apply either to the top or to the ASTM D883—Definitions of Terms

bottom. Relating to Plastics.
1.3.5 Manufacturer: The person, ASTM D1599—Test Method for
firm, or corporation that actually manu- Short-Time Hydraulic Failure Pressure
factures the tank. of Plastic Pipe, Tubing, and Fittings.
1.3.6 Purchaser: The person, firm, ASTM D2583—Test Method for In-
corporation, or government subdivision dentation Hardness of Rigid Plastics by
entering into a contract or agreement to Means of a Barcol Impresser.
purchase a thermosetting fiberglass-rein- ASTM D2584—Test Method for igni-
forced plastic tank according to this tion Loss of Cured Reinforced Resins.
standard. ASTM E84—Test Method for Surface
1.3.7 Su[fticing \eil: The finishing Burning Characteristics of Building
reinforcement-mat layer applied to the Materials.
laminate surface, usually to obtain im- Code of Federal Regulations, Title 21,
proved surface finish or corrosion protec- Food and Drugs.
tion.
Sec. 1.5 Inspection and Testing by
Sec. 1.4 References Purchaser
When specific references are cited 1.5.1 [nspection at manufacturer k
without dates, the designation shall be plant. If the purchaser wants to inspect
construed as referring either to the latest the plastic tank at the manufacturer’s
revision under the same number or to plant, the purchaser shall so specify in the
superseding documents under a new contract or agreement the extent of the
number, except for provisions in the inspection requested.
revised documents that are clearly in-
1.5.2 A mess to ~wk. The purchaser
applicable.
shall have free access to those parts of the
The following is a list of references used
manufacturer’s plant that are necessary to
in this standard:
ASTM* C581—Test Method for ensure compliance with this standard.
The manufacturer shall make available
Chemical Resistance of Thermosetting
for the purchaser’s use such test equipment
Resins Used in Glass Fiber Reinforced
and apparatus, and shall provide such
Structures. .
assistance, as are necessary for inspection.
ASTM D229—Method of Testing
Rigid Sheet and Plate Materials Used for 1.5.3 Responsibiiit]. Inspection by
Electrical Insulation. the purchaser or failure of the purchaser
ASTM D618—Methods of Condition- to provide inspection shall not relieve the
ing Plastics and Electrical Insulating manufacturer of the responsibility to
Materials for Testing. furnish materials and perform work in
ASTM D638—Test Method for Tensile accordance with this standard.
Properties of Plastics. 1.5.4 Tests. If any sample fails to
ASTM D790—Test Methods for meet the requirements of this standard
Flexural Properties of Unreinforced and during the tests made by the purchaser on
Reinforced Plastics and Electrical In- material samples under Sec. 1.6, the tank
sulating Materials (Metric). shall be rejected or retested.
1.5.5 Rejec!ion. If the plastic tank
*American Society for Testing and Materials, 1916 fails to meet the requirements of this
Race St., Philadelphia, PA 19103. standard, the unit shall be rejected.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 PLASTIC TANKS 3

Sec. 1.6 Tests Sec. 1.7 Affidavit of Compliance

1.6.1 Ph}sical properties. Each The manufacturer shall, if so specified
plastic tank, as specified in Sec. 1.6.2, by the purchaser, furnish an affidavit that
,
shall be tested for tensile strength, flexural certifies that the plastic tank or tanks
strength, and hardness. furnished comply with the requirements
1.6.2 Test ofrank shell. Tanks with a of this standard and the purchaser.
diameter of less than 8 ft and a height-to- 1.7.1 Perfbrnlance requirements. The
diameter ratio less than two will require resins, reinforcement, colorants, filters,
the submission of test results of a similar and other materials, when combined as a
tank wall laminate to the one used to structure, shall produce tanks that meet
construct the tank. All tanks with a the performance requirements of this
diameter greater than and including 8 ft standard.
and a height-to-diameter ratio greater 1.7.2 Qualification, fot- potable ~iater
than two will require a test of the shell of .setn’ice. The materials used to construct
the actual tank to be supplied. The sam- the tanks shall contain no ingredient in an
ples tested shall be taken from the wall or amount that has been demonstrated to
test cylinders. migrate into water in quantities considered
1.6.3 Chemical properties. If re- to be toxic, as described in the Code of
quired by the purchaser, chemical tests to Federal Regulations, Title 21, Food and
verify chemical resistance of the tank shall Drugs.
be conducted. 1.7.3 C’ert@ca[ion. The plastic tanks
1.6.4 Specimens. The manufacturer shall be tested and certified as suitable for
shall provide test specimens from the potable water use by a testing laboratory
plastic tank or tanks to be supplied as acceptable to the purchaser, in accordance
specified. with the requirements in Sec. 1.7.2.

Section 2—Materials

Sec. 2.1 Resin 2.1.1.3 Resins shall contain no pig-

ments. dyes, or colorants, except as per-
2.1.1 Poljester re.wn. The resin shall
be the commercial grade or blend of mitted under Sec. 3.4.2.4.
polyester specified for grade 1 fiberglass- 2.1.1.4 Fire-retardant agents may be
reinforced polyester resin. The resin shall added for improved fire resistance. (See
not contain fillers or pigments except as note in Appendix B.)
required in Sec. 2.1.1.1, Sec. 2.1.1.2, Sec.
2.1.1.3, and Sec. 2.1.1.4. Sec. 2.2 Reinforcing Material
2.1.1.1 Up to 5 percent (by weight) 2.2.1 Fiberg/a.w. The reinforcing
thixotropic agent that will not interfere material shall be a commercial-grade glass
with visual inspection may be added for fiber having a coupling agent; it shall be
viscosity control. Resin pastes used to fill compatible with the resin used and suit-
crevices before overlay shall not be subject able for the particular fabrication tech-
to this limitation. nique. The reinforcing material used to
2.1.1.2 Ultraviolet absorbers may be fabricate the tank shall be comparable to
added to the final resin coating to improve that used to generate corrosion-resistance
weather resistance. and physical-property design data.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
4 AWWA D120-84

Sec. 2.3 Surfacing Materials Sec. 2.3.1.1.

2.3.1.1 Under service conditions
2.3.1 Su[~acing vei/. The surfacing— where thechemica] environment attacks
veil shall be a commercial-grade chemi- the glass fibers, synthetic surfacing mate-
cal-resistant (grade C) glass fiber and a rials conforming to the requirements of
coupling agent, except as permitted under this standard may be used.

Section 3—Requirements
Sec. 3.1 General Requirements helically-wound tank having a maximum
The plastic tanks shall be compounded angle of wind of 80 degrees measured
and constructed so as to conform to the from the tank axis.
requirements of this standard. 3.2.1.4 The minimum wall thickness
3.1.1 E.t-tei-ior ,finish. The exterior (z) shall be determined by:
finish shall bean unpigmented resin coat- P/l 0.036 Y HD
,=—=
ing or a pigmented protective coating.
2SH 2 (ET) (z)
3.1.2 Workmanship. The workman-
ship shall be in accordance with good Where:
commercial practices. The tank manu- P= pressure 0.036 H, psi
factured shall be free of injurious defects H = fluid head, in
y = specific gravity
of fluid
and shall meet the appearance require-
D = inside diameter of tank, in.
ments of Sec. 3.4.2.
SH, El; and Z are as defined in Sec. 3.2.1.1.
Sec. 3.2 Physical Properties The minimum thickness shall not be
3.2.1 Filament -\~’ound iaminates. less than 0.18 in.
The maximum hoop stress of the total 3.2.2 Contact-molded laminates.
laminate, defined as the filament winding Type I tanks and the joints and heads of
plus inner surface and interior layer, shall type 11tanks shall be shop fabricated by
be limited by the allowable movement the contact-molding process in the manu-
(strain) of the tank wall when filled with facturer’s plant. Contact-molded lami-
fluid. . nates for type I tanks shall meet the
3.2.1.1 The maximum allowable hoop minimum property requirements listed in
stress shall be determined by the following Table 1. (See note in Appendix B.)
formula:
3.2.3 Head. The head shall be able
S/, = (ET) (z) to support a 250-lb load on a 4-by-4-in.
Where: area. The minimum thickness shall be ~/16
S}{= hoop stress in. (See note in Appendix B.)
ET= hoop tensile modulus of the total 3.2.4 Be/tom. The minimum thick-
laminate (see Appendix A) ness for a flat, fully supported bottom
Z = allowable strain. shall be:
(See notes in Appendix B.)
3.2.1.2 The allowable hoop strain of Tank Diameter Minimum “I”hickness
fi in.
the tank wall shall not exceed 0.0010
in. /in. 56 J/!
6
3.2.1.3 Tanks shall have a longitu- >6but S12 ‘A
> 12 %
dinal strength at least equal to that of a

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 PLASTIC TANKS 5

TABLE 1
Requirements .fc)r T\’pe [ Tank Contact-Molded Reinforce(t- Pelt’es!er Laminates
.
[,aminate Thickncw
Property at 23° C (73.2° F)
~/16 in. 1/4 in. ~/16in. -f/x in. and ,qreater

Ultimate tensile strength,

min., psi 9000 I2000 I3500 15000
Flexural strength, min., psi 16000 19000 20000 22000
Flexural modulus of elasticity
(tangent), min., psi 700000 800000 900000 I 000000

The radius of reinforcement shall not be be acceptable for the chemical environ-
less than 1 in. ment, including the concentration and
3.2.5 Swface cure. The degree of service temperatures.
cure of the resin-rich surface shall be
checked by the Barcol hardness test. The Sec. 3.4 Construction
surface shall have Barcol hardness of at 3.4.1 Laminate construction. The
least 90 percent of the resin’s manu- laminate shall consist of an inner surface,
facturer’s minimum specified hardness an interior layer, and an exterior layer.
for the cured resin, when tested in (See notes in Appendix B.)
accordance with Sec. 4.2. This applies to 3.4.1.1 The inner surface exposed to
both interior and exterior surfaces. (See the contents shall be a reinforced layer 10
note in Appendix B.) to 20 mil thick. Reinforcing materials
3.2.6 Vents. Closed-top tanks shall shall be chemically resistant glass-surface
be positively vented to the atmosphere. mat, or a synthetic veil. (See notes in
Minimum vent size shall be equal to the Appendix B.)
largest outlet or inlet. 3.4.1.2 The interior layer shall follow
3.2.7 Testing. Tanks shall be tested the inner surface and be reinforced only
hydrostatically and jnspected for leaks with noncontinuous glass strands applied
before being placed into service. Leaks in a minimum of two plies of chopped
shall be repaired with the same materials strand mat or, alternately, in a minimum
used in the tank construction. of two passes by the spray-up process.
3.2.8 Dimensions and tolerances. Glass content shall be 20 to 30 percent by
●
Tank diameters shall be measured in- weight. Before the filament winding is
ternally. Tolerance on the inside diameter, applied, the interior layer shall be allowed
including out-of-roundness, shall be f 1 to gel completely so that the corrosion
percent. Measurements shall be taken barrier will not be squeezed down to a
with the tank in a vertical position. thin layer of glass content of more than 30
Tolerance on overall height shall be f ~ percent. The combined thickness of inner
in. surface and interior layer shall not be less
than 0.10 in. (See note in Appendix B.)
Sec. 3.3 Chemical Properties
3.4.1.3 If the exterior layer is fila-
3.3.1 Chemical re.~istance. The fiber- ment-wound, then subsequent reinforce-
glass-reinforced resin shall have been ment shall be continuous-strand roving in
evaluated in accordance with Sec. 4.3 to accordance with Sec. 3.2.1.3. That rein-

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
6 AWWA D 120-84

forcement, in combination with Sec. of not more than 2 pits/ sq ft, providing
3.4.1.1 and Sec. 3.4.1.2, is needed to the pits are less than Ifiin. in diameter, not
satisfy the minimum wall thickness speci- more than 1/~2in. deep, and are covered
fied in Sec. 3.2.1.4. The thickness of the with sufficient resin to avoid exposure of
filament-wound portion of the tank shell the inner surkce reinforcement. Some
may be varied with tank height (tapered- wrinkles are permissible, provided their
wall construction), providing the require- surfaces are smooth and free of pits.
ments of this standard are met at any 3.4.2.2 The finished laminate shall be
height level. If additional longitudinal as free as commercially practical from
strength is required, other reinforcement. objectionable visual defects, such as
such as woven fabric, chopped-strand foreign inclusion, dry spots, air bubbles,
mat, or chopped strands, may be inter- pinholes, pimples, and delamination.
spersed in the winding to provide addi- 3.4.2.3 The exterior surface shall be
tional strength. Glass content of filament smooth with no exposed fibers or sharp
winding shall be 50 to 80 percent by projections.
weight. Only those constructions evalu- 3.4.2.4 The outside surface of the
ated for design properties in Sec. 4.1.3.7 tank shall not be pigmented, painted, or
shall be used. dyed, unless agreed on by the manu-
3.4.1.4 If the exterior layer is contact- facturer and the purchaser. (See note in
molded, then the exterior layer or body of Appendix B.)
the laminate shall be of a chemically 3.4.3 Join[s. Joints between tank
resistant construction suitable for the wall sections shall be overwound or over-
designated service and provide the addi- laid to a thickness as calculated in Sec.
tional strength necessary to meet the 3.2.1.4, using the appropriate modulus
tensile and flexural requirements. Where value for the type of laminate construction
separate layers such as mat, cloth, or and dimensional values at the point
woven roving are used, all layers shall be height level. (The flexural modulus values
lapped a minimum of 1 in. Laps shall be from Table 1 may be used as an approxi-
staggered as much as possible. If woven mation of the tensile modulus of hand
roving or cioth is used, a layer of lay-up laminates.)
chopped-strand glass shall be placed as 3.4.3.1 The width of the first layer of
alternate layers. Hand-work finish is joint lay-up shall be 3 in. minimum.
acceptable, but enough resin shall be Successive layers shall uniformly increase
present to prevent exposed fibers. The in width. The reinforcement shall be
appearance of the exterior surface shall be centered on the joint and shall extend on
in accordance with Sec. 3.4.2. each side of the joint a sufficient distance
3.4.1.5 For added chemical resistance to make it at least as strong as the tank
an exterior surface of chopped glass or wall in the vertical direction. Minimum
surfacing veil, or both, made from either joint widths are given in Table 2.
glass or organic fibers, may be used. 3.4.3.2 The interior of the joint shall
Unless otherwise specified, the exterior be sealed by a laminate of a minimum of
shall contain stabilizers to prevent ultra- two layers of 1.5-oz mat overlayed with
violet degradation. appropriate surface mat or veil. Minimum
3.4.2 Appearance. (See note in width is 4 in. This inner reinforcement
Appendix B.) shall be considered to be a corrosion-
3.4.2.1 The exposed surfaces shall be resistant barrier only and not a structural
free of cracks and crazes. The surface material.
shall have a smooth finish with an average 3.4.3.3 Joints shall be free of objection-

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 PLASTIC TANKS 7

TABLE 2
Mininllii]l Willths @ O\’erlat’ed Joint.y

H* (f/)X diame(ers (//)

60 I 00 I40 180 220 260 300 340 380 420 460 500
Minimum width
of outside
oterlay. 117. 4 4 5 6 7 8 9 10 II 12 13 14
Minimum width
of inside
overlay, in. 4 4 4 4 4 4 4 4 4 4 4 4
*H is the distance in feet from the top of the liquid level to the joint.

able crevices. Crevices between joined fluid as the tank wall (Sec. 3.4.1.1 and
pieces shall be filled with resin or thixo- Sec. 3.4. 1.2). Joints between head and
tropic resin paste leaving a smooth surface shell wall shall conform to Sec. 3.4.3.
for lay-up. 3.4.4.1 Top heads may be integrally
3.4.3.4 All cured, noninhibited resin attached or removable and may be any
surfaces where parts are to be joined shall shape.
first be roughened by sanding or sand 3.4.4.2 Bottom heads may either be
blasting. The roughened area shall extend fabricated integrally with the shell wall or
beyond the work areas so that no lay-up is be separately molded with a flange and
made on a molded surface. Surfaces shall subsequently jointed to the shell. In either
be clean and dry before lay-up. The entire case, the inner surface of the head shall
roughened area shall be resin coated present the same corrosion-resistant con-
when the joint is made. struction to the fluid as the tank wall (Sec.
3.4.3.5 All cut edges shall be coated 3.4.1.1 and Sec. 3.4. 1.2). Joints between
with resin so that no glass fibers are head and shell wall shall conform to Sec.
exposed and all voids are filled. 3.4.3.
3.4.3.6 When air-inhibited resins are 3.4.4.2.1 For integral heads, shell and
cured with an air-t?xposed surface, the bottom reinforcement shall overlap a
lay-up shall be coated with a paraffin- minimum of 4 in.
containing resin to achieve full surface 3.4.4.2.2 For separately molded
cure. (The acetone sensitivity test can be heads, the minimum straight flange length
used to check surface cure. ) Use of other is 4 in.
techniques such as sprayed or wrapped 3.4.4.2.3 The knuckle area (the
films are also acceptable methods of radiused transition of the head to the
attaining an air-free cure. shell) shall be reinforced to the same
3.4.4 Heads. Heads may be fabri- thickness and width as a joint (Table 2). It
cated integrally with the tank wall or shall be centered over the knuckle, and
separately by contact molding. Heads the reinforcement shall taper uniformly
fabricated by contact molding shall satisfy into the bottom thickness over a distance
the mechanical property requirements of of not less than 6 in.
Sec. 3.2.2. In either case, the inner surface 3.4.4.2.4 Flat bottom tanks must have
of the head shall present the same full bottom support. Tanks with conical
corrosion-resistant construction to the or rounded bottom heads must have

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 AWWA DI 20-84

TABLE 3 TABLE 4
Pipe .fi>r Nozzle A .ssemhlj Flange Thick ne.~.~,fi~rReinjijrced
Polj’ester Nozzles
Contact-Molded Polyester Pipe Minimum
Wall Thickness Pipe Sile Minimum Flange Thickness
Pipe Size Minimum Wall Thickness in. in,
tn. in. 2 I/2

2-12 Jll(l 3 l/>

14-24 I/4 4 I ]2

30 S/1~ 6 I/2

36 ‘/8 8 9/16
42 3/8 10 11/,6

12 3/4
Filament-Wound and Centrifugally Cast-Polyester
Pipe Minimum Wall Thickness 14 13/,6

16 718
Pipe Size Minimum Wall “rhickness
in. in. 18 15/1,6

20 I
2-3 0.140
24 1 l/~
4-6 0. [80
30 I 3/8
8-12 0.200
36 1 3/4

42 2
other means of support, such as a cradle,
skirt, or extension legs.
NOTE 1: Based on flat-faced flanges with full-
3.4.5 Fittings. Standard flanged face soft gaskets.
nozzles shall be fabricated either from
contact-molded polyester pipe and a suit- NC)I~ 2: Flange dimensions (except thickness)
able flange, from integrally molded pipe and bolting correspond to the following
standards: 2-in. through 24-in. sizes—
and flanges, or from polyester machine- ANSI Standard B16.5, Pipe Flanges
made pipe and a suitable flange. Vents do and Flanged Fittings, for 150-lb steel
not require flanges, but they shall use flanges; 30-in, through 42-in. sizes—
either contact-molded, integrally molded, ANSI Standard B16.1, Cast Iron Pipe
Flanges and Flanged Fittings Class 25,
or polyester machine-made pipe. Where 125,250, and 800, for 125-lb Cl flanges.
flange fittings are used, suitable gaskets
shall be furnished. Flange gaskets shall be No’r~ 3 This table is based on a safety factor of
full face, M in. minimum thickness, and 8 to I and a ffexural strength of 20000
have a durometer hardness of 40 to 60, psi, a value slightly under the minimum
flexural strength for laminates ~/s in.
unless otherwise specified or required for
and up (see Table 1) due to the
the service conditions. (See notes in manufacturing technique.
Appendix B.)
3.4.5.1 The pipe used shall have mini- ness of flange hub reinforcement measured
mum wall thickness as shown in Table 3. at the top of the fillet radius shall be at
3.4.5.2 Flanges shall be of the mini- least one half the flange thickness, and
mum thickness given in Table 4. Bolting shall be tapered uniformly the length of
- pattern shall be in accordance with API*
or ANSI~ standards.
*American Petroleum Institute, 21OI L Street,
3.4.5.2.1 The minimum flange shear N. W., Washington, DC 20037.
surface shall be four times the flange ~American National Standards Institute, 1430
thickness, indicated in Table 4. The thick- Broadway, New York, NY 10018.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 PLASTIC TANKS

\
Fillet Reinforcement Diameter
Nozzle 02
‘ad’”’> +%----f
- Diameter .__F --1

al
zL

G
Shear
Surface E
P * m
—— —_— .__—_—
I

‘==---J--.J
Thickness
w
Figure 1. Flanged Nozzle

the hub reinforcement. The fillet radius,

where the back of the flange meets the
hub, shall be % in. minimum (Figure l).
3.4.5.2.2 The flange face shall be
perpendicular to the centerline of the pipe
within 1degree, and it shall be flat to* i/~z
in. up to and including 18-in. diameter
and f i/lc in. for larger diameters unless
otherwise specified. (See note in Appen-
dix B.)
3.4.5.3 At assembly, there shall be a
minimum dimension of 3 in. from the
wall of the tank to the flange hub for
compression-molded flanges, or to the
flange back for hand lay-up flanges.
Where angular loadings are anticipated,
nozzles shall be supported by a suitable
gusseting technique.
3.4.5.3.1 Standard orientation shall
have bolt holes straddling the principal
centerline of the vessel.
3.4.5.3.2 Location of nozzles on the
vessel shall be * 1%in. Tolerance on angle
of nozzle centerline shall be within 1
degree.
3.4.5.3.3 When cut for
10 AWWA D120-84

TABLE 5 Reinforcement Y

>
[Typical)
Shear- Bond A Yea— Nozzle.Y * ( In Accordance I
With Sec. 3.4.5 .3.3 I
A
Pipe Wall Thickness Bond Area I.ength
;)1. ;}1.

Tank
Wall
> { Typical)
j
*Shear-bond areas A are shown in Figures 3 ;ind 4. Nozzle -’-+ ~ A = Shear Bond
7J
\
\ >
a ring bonded to the top of the shell.
Alternatively, the shell shall be overwound INN i
or overlaid to provide sufficient rigidity Figure 3. Installed Nozzle
for retaining the shape of the tank. (With Pipe Penetration)

3.4.6. I External stiffeners, when used,

may be made with additional circum-
ferential windings. Overwound or overlaid
cores are permissible alternatives provided
that they are completely enclosed in
reinforced plastic.

3.4.7 Hold-dot{w lugs. Hold-down

lugs shall be provided on all tanks for
outdoor service and, where required, for
special service and local design conditions.

3.4.8 Lif/ /ug.Y. Tanks shall be Figure 4. Installed Nozzle

equipped with suitable lifting devices. (Without Pipe Pentration)

Section 4—Testing Methods

Sec. 4.1 Physical Properties 4.1.3 Procedures:

4.1.1 Specimens. Mechanical and 4.1.3.1 Determine the glass content
physical properties on type 1 tanks shall in accordance with ASTM D2584, except
be determined on specimens cut from that the specimens tested shall be approxi-
laminates prepared in the same construc- mately 1 sq in. in area, and low-tempera-
tion and by the same techniques as the ture preignition prior to replacement in a
process equipment used for the tanks’ muffle furnace is recommended. The
fabrication. On type 11tanks, the proper- average of five specimens shall be con-
ties shall be determined in accordance sidered to be the glass content.
with Sec. 4.1.3.6.
4.1.2 Conditioning. The test speci- 4.1.3.2 Sec. 4.1.3.3, Sec. 4.1.3.4, and
mens shall be conditioned in accordance Sec. 4.1.3.5 refer only to tests conducted
with procedure A of ASTM D6 18. on type 1 (contact-molded) tanks. Sec.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 PLASTIC TANKS 11

4.1.3.6 refers only to tests conducted on Barcol instrument shall be verified by

type 11(filament-wound) tanks. comparing with blanks having known
4.1.3.3 Determine tensile strength in readings of 85–87 and 42–46. Ten readings
accordance with ASTM D638, except of the clean, resin-rich surface shall be
that: made. After eliminating the two high and
4.1.3.3.1 The dimensions of all speci- the two low readings, the average of the
mens, regardless of thickness, shall be remainder shall be the reported hardness
those shown for specimens “over 1Ainch reading. (See notes in Appendix B.)
thick” in Figure 1 of ASTM D229.
4.1.3.3.2 The specimens shall be the Sec. 4.3 Chemical Resistance
actual thickness of the fabricated article.
Chemical resistance of the resin shall be
Specimens shall not be machined on the
determined using ASTM C581. The
surface.
reinforcing materials prescribed in the test
4.1.3.3.3 Tensile strength shall be the
laminate are only for the purpose of
average of five specimens tested at a cross-
establishing a uniform basis for compari-
head speed of 0.20 to 0.25 ipm.
son; they may not necessarily represent
4. 1.3.4 Determine the flexural
the preferred materials for the particular
strength in accordance with method I of
environment. This procedure may be
procedure A and Table 1 of ASTM D790,
adapted to test or evaluate components,
except that the specimens shall be the
composition or fabrication variations,
actual thickness of the fabricated article
and production samples.
and the width shall be 1 in. Other dimen-
4.3.1 Laminate chemical resistance.
sions of specimens shall be as designated
For polyester-resin laminate testing, use
by ASTM D790. Specimens shall not be
ASTM C581 with the following additions
machined on the surface. Tests shall be
and definitions:
made with the resin side in compression,
4.3.1.1 Determine the standard test
using five specimens.
laminate in accordance with Appendix
4.1.3.5 Determine the tangent modu-
Al of ASTM C581 and Sec.4.3.l.l.l and
lus of elasticity in flexure in accordance
Sec. 4.3.1 .1.2 of this standard.
with ASTM D790, method I of procedure
4.3.1 .1.1 The 10-mil surfacing mat
A.
referred to in Sec. 5.2.3.2 of ASTM C581
4.1.3.6 Determine the design stresses
shall be made of chemical-resistant glass.
and moduli of elasticity by ( 1) test data
4.3.1 .1.2 Cure the standard test lami-
based on strain measurements on small-
nate at room temperature for 16 hours.
diameter, filament-wound cylinders made
Cure further, if necessary, to produce a
to the same laminate construction, helix
Barcol hardness equal to the resin manu-
angle, glass content, liner construction,
facturer’s minimum specified hardness
and resin as the full size tank, and (2) using
for the cured resin.
the test method of ASTM D1599, with
4.3.1.2 Tests may be conducted at
end closures that prevent the application
any or all of these temperatures—23° C,
of axial tensile stress or hydrostatic
50° C, 100° C (~ 2° C), reflux temperature.
pressure.
4.3.1.3 The following reagents are
suggested for use in obtaining general
Sec. 4.2 Hardness comparative chemical data. The test
In accordance with ASTM D2583, the solutions shall not be agitated; that is, the
Barcol Impresser shall be used for deter- exposures to test specimen shall be under
mining hardness. Calibration of the static conditions.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
12 AWWA D120-84

w
25-perccmt sulfuric acid Ethyl acetate
Hydrochloric acid 15-percent methyl ethyl ketone
5-percent nitric acid Monochloroberrzene
25-percent acetic acid Perchloroethylene
Phosphoric acid n- Heptane
5-percent sodium hydroxide Kerosene
10-percent sodium carbunate Toluene
Saturated sodium chloride 5-percent hydrogen peroxide*
95-percent ethanol Distilled water*
5fi-Percent sodium hypochlorite* Ammonium hydroxide, concentrated
5-percent aluminum potassium Carbon tetrachloride
15-percent sulfate Soda ash (sodium carbomitc)
Sodium chloride 16-percent sodium hypochlorite
Lime slurry (calcium hydroxide) Ferrous sulfate
Ammonium sulfate Ltquid sodium silicate
Liquid alum Ferric sulfate
Sodium aluminate Aqua ammonia
Ferric chloride Sodium polyphosphate, glassy
Caustic soda (sodium hydroxide) Powdered activated carbon slurry
Sodium tripolyphosphate Copper sulfate
Sodium bisulfite Sodium fluoride
Potassium permanganate Hydrofluosilicic acid
Sodium silicofluoride Proprietary coagulant aids
Sodium chlorite

*Replace every 48 hours with fresh solution.

4.3.1.4 Obtain data for specimens 4.3.1.6 Report data in tabular form
exposed for 30, 90, and 180 days and 1 for all parameters tested. Describe ade-
year immersion; also obtain data for one quately the composition, including resin,
set of control specimens immediately accelerators, catalysts, and reinforce-
following the curing period and for ments, and the fabricating and curing
another set after aging in air at the test conditions of the laminate tested.
temperature for the total test period.
Sec. 4.4 Surface Burning
4.3.1.5 Determine thickness, Barcol Characteristics
hardness, flexural strength and modulus, The surface burning characteristic shall
and appearance at each time interval. be determined in accordance with ASTM
Appearance observations shall include E84. Test results of a similar tank maybe
any surface changes, color changes, submitted, unless otherwise specified by
obvious softening or hardening, crazing, the purchaser.
delamination, exposure to fibers, or other
effects indicative of complete degradation Sec. 4.5 Hydrostatic Testing
or potential failure. Calculation of per- The tank shall be filled with water and
centage change in a property shall be left standing for 24 hours. The tank shall
based on the property value obtained show no visual evidence of leakage or loss
immediately following the curing period. of water during the test period.

Section 5—Retest
Sec. 5.1 Retest
If any failure occurs, the plastic tank accordance with agreement between the
may be retested to establish conformity in purchaser and the manufacturer.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 PLASTIC TANKS 13

Section 6—Marking
Sec. 6.1 Manufacture and Service 1. Name and location of manufac-
Identification turer.
The tank shall carry a plaque, perma- 2. Date of manufacture.
nently affixed to the outside shell, near 3. Capacity.
the inlet or outlet nozzle or other location 4. Type and grade.
as approved, that shall show the following 5. Designed service media and condi-
information with permanently applied tion.
letters and numbers at least K in. high: 6. Precautions, if any.

Section 7—Shipping and Handling

Sec. 7.1 Shipping striking other objects may result in crack-
Tanks shall be mounted on cradles if ing the inner corrosion-resistant liner as
shipped in a horizontal position or on a well as the exterior of the tank.
suitable skid or pallet if shipped in a 7.2.3 Rolling. The tank shall not be
vertical position. The cradles or skid shall rolled or slid on rough surfaces.
be padded and secured to the bed of the 7.2.4 Working around tank. In
vehicle in a manner that will prevent working around the tank, care should be
dam~ge to the tank during normal exercised to prevent tools, scaffolding, or
handling. The tank shall be secured to the other objects from striking the tank or
cradle or skid so that there can be no being dropped inside the tank. Soft-soled
movement of the tank in relation to the shoes shall be worn by workers entering
skid or cradle. A suitable stiffening the tank. Ladders used inside or outside in
member shall be secured at the opening of contact with the tank shall be wooden or
open-top tanks. Tanks shall be loaded have cushion protection on both ends and
with at least a 2-in. clearance between the shall not be permitted to scratch or point
tank, including fittings, and the bulkheads load the surface.
or bed of the vehicle. When two or more 7.2.5 Lifting. A crane is recom-
tanks are shipped at oanetime, there shall mended for use in lifting and erecting the
be sufficient clearance or padding between tank. The clearance between the head
tanks to prevent contact during transit. shackle of the crane and the tank should
at least equal the overall length of the
Sec. 7.2 Handling tank. If this is not possible, a spreader bar
The following normal precautions shall must be used to approximate the same
be taken in handling the tank at the angle in lifting.
destination: 7.2.5.1 Tanks not equipped with
7.2.1 Rigging. Proper rigging prac- lifting lugs shall be lifted by use of canvas
tices shall be observed at all times. or suitable rope slings placed carefully
Hoisting-equipment operators shall attach near each end of the tank. Tanks may be
a guideline to prevent the tank from moved by using fork lift trucks equipped
swinging without control. with padded forks.
7.2.2 Damage. The tank shall not 7.2.5.2 Chains or cables shall not be
be dropped or allowed to strike any other put around the tank or used for lifting or
object. Damage caused by dropping or handling the tank. No fittings other than

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
14 AWWA D 120-84

lifting lugs shall be used for lifting. shall be placed on the shipping cradles
7.2.6 Storing. When storing the and tied down so that it cannot roll due to
tank on the ground prior to installation, it winds or sloping elevation.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 Appendix A
Expression of Hoop Tensile Modulus of a Laminate

This appendix is,fi]r in~i~rmation onl~ and is not a part qf A W WA D120.

The hoop tensile modulus of a laminate, EF~ = hoop modulus of filament winding,
composed partially of filament winding psi
and partially of a contact-molded liner, is Et = modulus of liner, psi

expressed by: t = total thickness, in.

t [. = liner thickness, in.
tFw /Fw = filament winding thickness equals
tL
ET= EFW ~ +EL~ t– t[,in.
This expression will give a good
Where: approximation of total laminate modulus
ET = hoop modulus of total laminate, psi for values of E’FWof 3.0-6.0 X 106 psi.

15

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 Appendix B
Explanatory Notes to D120-84

This appendi.v i.f,ji)r infi)rnla(ion onl.i and is nof a part of’ A W WA D120.

The following notes refer to various equipment may require additional local
sections of AW WA D 120-84. These notes reinforcement or the use of stiffener ribs,
are meant to further explain the sections or both.
to which they refer. 3.2.5 NOTE. Barcol hardness is af-
1.2.1 NOTE. Filament-wound tanks fected by the type and concentration of
are normally constructed in combination reinforcing materials and fillers in the
with contact molding. The primary surface layer and the test temperature.
method used for constructing the tank 3.4. I NOTE 1. The compositions
shell is used to define the type. specified for the inner surface and interior
2.1.1.4 NOTE. Additions to the resin layer are intended to achieve optimum
may interfere with visual inspection of chemical resistance.
laminate quality. NOTE 2. Different resin systems
3.2.1.1 NOTE 1. Tanks for outdoor may be used within the tank; that is, the
installation shall be designed for the effect resin used for the liner may be different
of wind loading and other environmental than the resin used for the filament
factors. windings.
NOTE 2. Tanks with significant phy- 3.4.1.1 NOTE /. This resin-rich layer
sical loadings other than fluid head, such will usually contain less than 20 percent of
as, but not restricted to, side-mounted reinforcing material. A specific limit is not
equipment, violent agitation, unusually included because of the impracticability
high flow rates, and unsupported bot- of determining this value in the finished
toms, shall be given special design con- product.
siderations. NOTE 2. The use of organic mate-
3.2.2 NOTE. If the specified thick- rials, such as acrylic and polyester fibers,
ness for a laminate is 1Ain., reading from may give lower readings for the Barcol
Table 1, then a minimum tensile strength hardness of the surface. However, this
of 12000 psi is required. By multiplying lower Barcol reading does not necessarily
thickness times minimum tensile strength, indicate undercure of the surface under
a value of 3000 lbf breaking load for a these circumstances.
l-in. wide specimen is obtained. A lami- 3.4.1.2 NOTE. The use of resins in
nate having tensile strength of 10000 psi the inner surface and interior layer having
will, therefore, be acceptable for the ‘~-in. an elongation (as measured on a pure-
requirement if it has an actual thickness of resin casting) of less than 2 percent may
at least 0.3 in. require a design that will maintain strain
3.2.3 NOTE. Support of auxiliary level below 0.0010 in. / in.

16

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 PLASTIC TANKS 17

3.4.2 NOTE. A representative lami- ,\’OTE 2. Vent design and installa-

nate sample may be used for determina- tion may be of a lighter duty construction
tion of acceptable surface finish and by manufacturer-purchaser agreement.
visual imperfections. 3.4.5.2.2 NOTE. Other flanges
3.4.2.4 NOTE. The tank may be agreed on between the manufacturer and
either shop-primed for field painting or the purchaser are acceptable provided
finish-painted by manufacturer-purchaser that they produce a tight joint.
agreement. The paint should not be
applied until the inspection has verified 4.2 NOTE 1. Barcol hardness is
that the tank meets the requirements of affected by the type and concentration of
this standard. The addition of pigments, reinforcing materials and fillers in the
dyes, or colorants may interfere with the surface layer and by the test temperature.
visual inspection of the laminate quality. NOTE 2. To test for surface cure of
3.4.5 NOTE 1. Standard side-entry polyester resins, rub a small amount of
manways shall be designed as large- acetone on the laminate surface until the
diameter nozzles. Other manway designs acetone evaporates. If the surface becomes
are by manufacturer–purchaser agree- softened or tacky, other test(s) should be
ment. performed to verify surface cure.

Copyright (C) 1998 American Water Works Association, All Rights Reserved.
 @
4P-1 M-441 20-9/96-MG Printed on recycled paper
Copyright (C) 1998 American Water Works Association, All Rights Reserved.