ASTM D3299-18

Standard Specification for Filament-Wound Glass-Fiber-Reinforced Thermoset Resin Corrosion-Resistant Tanks

ABSTRACT
This specification covers cylindrical corrosion-resistant tanks made of commercial-grade glass-fiber-reinforced polyester or vinylester thermoset resin fabricated by filament winding for above-ground vertical installation, to contain aggressive chemicals at atmospheric pressure as classified herein. This specification does not address the design of vessels intended for pressure above atmospheric, vacuum conditions, except as classified herein, or vessels intended for use with liquids heated above their flash points. Included are requirements for materials, properties, design, construction, dimensions, tolerances, workmanship, and appearance.
SCOPE
1.1 This specification covers cylindrical tanks fabricated by filament winding for above-ground vertical installation, to contain aggressive chemicals at atmospheric pressure as classified herein, and made of a commercial-grade polyester or vinylester resin. Included are requirements for materials, properties, design, construction, dimensions, tolerances, workmanship, and appearance.  
1.2 This specification does not cover the design of vessels intended for pressure above atmospheric or under vacuum conditions, except as classified herein, or vessels intended for use with liquids heated above their flash points.  
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.4 Special design consideration shall be given to tanks subject to environmental and/or mechanical forces such as seismic, wind, ice, agitation, or fluid dynamic forces, to operational service temperatures greater than 180°F (82°C) and to tanks with unsupported bottoms.  
1.5 The following safety hazards caveat pertains only to the test method portion, Section 11, of this specification:  This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
Note 1: There is no known ISO equivalent to this standard.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jul-2018
• ICS: 23.020.10 - Stationary containers and tanks
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.23 - Reinforced Thermosetting Resin Piping Systems and Chemical Equipment

Relations

• Replaces: ASTM D3299-10 - Standard Specification for Filament-Wound Glass-Fiber-Reinforced Thermoset Resin Corrosion-Resistant Tanks
• Effective Date: 01-Aug-2018
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM D2996-23 - Standard Specification for Filament-Wound “Fiberglass” (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
• Effective Date: 01-Oct-2023
• Refers: ASTM F412-20 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Apr-2020
• Refers: ASTM C581-20 - Standard Practice for Determining Chemical Resistance of Thermosetting Resins Used in Glass-Fiber-Reinforced Structures Intended for Liquid Service
• Effective Date: 15-Feb-2020
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2019
• Refers: ASTM F412-19 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Jan-2019
• Refers: ASTM D883-18a - Standard Terminology Relating to Plastics
• Effective Date: 01-Dec-2018
• Refers: ASTM D883-18 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2018
• Refers: ASTM D2584-18 - Standard Test Method for Ignition Loss of Cured Reinforced Resins
• Effective Date: 15-Sep-2018
• Refers: ASTM D1599-18 - Standard Test Method for Resistance to Short-Time Hydraulic Pressure of Plastic Pipe, Tubing, and Fittings
• Effective Date: 01-Sep-2018

Overview

ASTM D3299-18: Standard Specification for Filament-Wound Glass-Fiber-Reinforced Thermoset Resin Corrosion-Resistant Tanks details requirements for manufacturing cylindrical, above-ground vertical tanks designed to contain aggressive chemicals at atmospheric pressure. These tanks are fabricated from commercial-grade polyester or vinylester thermoset resin using the filament winding process, providing enhanced strength and corrosion resistance. This standard, developed by ASTM International, specifies the materials, design, construction, dimensions, tolerances, workmanship, and appearance for producing reliable and durable tanks in corrosive environments.

Key Topics

• Tanks Covered: Cylindrical, above-ground, vertical storage tanks made by filament winding of glass-fiber-reinforced thermoset resin.
• Resin Types: Commercial-grade polyester or vinylester resins specified for chemical resistance.
• Installation: Tanks intended for above-ground service, vented to atmosphere or fume conservation systems, used at atmospheric pressure.
• Excluded Applications: Not applicable for tanks designed for internal or external pressures above atmospheric, vacuum conditions (except certain defined cases), or liquids heated above their flash points.
• Materials & Construction: Covers selection and requirements for resins, glass fiber reinforcement, and fabrication techniques to ensure chemical compatibility and laminate integrity.
• Design Considerations:
  • Structural requirements for corrosion-resistant barriers (liners), shell thickness, and reinforcement.
  • Special provisions for tanks subjected to environmental loads such as wind, seismic activity, or mechanical agitation.
  • Temperature limitations, notably service temperatures above 180°F (82°C) needing special attention.
• Quality Requirements: Defines standards for workmanship, appearance, acceptable tolerances, and minimum property values for laminates.

Applications

ASTM D3299-18 is widely used in industries that require safe storage of aggressive chemicals, including:

• Chemical Processing Plants: For storage of acids, bases, solvents, and other corrosive substances.
• Water and Wastewater Treatment: Used for holding tanks, chemical feed tanks, and process vessels where corrosion resistance and chemical compatibility are critical.
• Pharmaceutical and Food Industry: When safe containment of cleaning agents and process chemicals is needed.
• Industrial and Municipal Applications: Where above-ground, corrosion-resistant storage is required, especially in harsh environments.

Tanks built to ASTM D3299-18 offer:

• Long-term durability in environments with chemical attack
• Light weight compared to metal tanks, allowing easier installation and handling
• Robustness for outdoor service with appropriate design for UV protection and environmental stress
• Versatility for custom fabrication to meet site-specific needs

Related Standards

ASTM D3299-18 references and is complemented by several other standards in the field of reinforced plastic composites and corrosion-resistant equipment:

• ASTM C581: Practice for Determining Chemical Resistance of Thermosetting Resins
• ASTM C582: Specification for Contact-Molded Reinforced Thermosetting Plastic Laminates for Corrosion-Resistant Equipment
• ASTM D883: Terminology Relating to Plastics
• ASTM D2996: Specification for Filament-Wound “Fiberglass” Pipe
• ASTM D2997: Specification for Centrifugally Cast “Fiberglass” Pipe
• ASTM D4024: Specification for Machine Made “Fiberglass” Flanges
• ASTM D5421: Specification for Contact Molded “Fiberglass” Flanges
• ANSI B16.1: Cast Iron Pipe Flanges and Flanged Fittings (certain references for dimensional compatibility)

Note: There is no known ISO equivalent for ASTM D3299-18.

---

ASTM D3299-18 is essential for manufacturers, engineers, process plant designers, and procurement specialists seeking robust, reliable standards for glass-fiber-reinforced plastic tanks used in aggressive chemical storage. Compliance ensures safety, performance, and longevity in the most demanding environments.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D3299 −18
Standard Specification for
Filament-Wound Glass-Fiber-Reinforced Thermoset Resin
Corrosion-Resistant Tanks
This standard is issued under the fixed designation D3299; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This specification covers cylindrical tanks fabricated by
mendations issued by the World Trade Organization Technical
filament winding for above-ground vertical installation, to
Barriers to Trade (TBT) Committee.
contain aggressive chemicals at atmospheric pressure as clas-
sified herein, and made of a commercial-grade polyester or
2. Referenced Documents
vinylester resin. Included are requirements for materials,
2.1 ASTM Standards:
properties, design, construction, dimensions, tolerances,
C581Practice for Determining Chemical Resistance of
workmanship, and appearance.
Thermosetting Resins Used in Glass-Fiber-Reinforced
1.2 This specification does not cover the design of vessels
Structures Intended for Liquid Service
intended for pressure above atmospheric or under vacuum
C582SpecificationforContact-MoldedReinforcedThermo-
conditions, except as classified herein, or vessels intended for
setting Plastic (RTP) Laminates for Corrosion-Resistant
use with liquids heated above their flash points.
Equipment
1.3 The values stated in inch-pound units are to be regarded D618Practice for Conditioning Plastics for Testing
as standard. The values given in parentheses are mathematical D883Terminology Relating to Plastics
conversions to SI units that are provided for information only D1599Test Method for Resistance to Short-Time Hydraulic
and are not considered standard. Pressure of Plastic Pipe, Tubing, and Fittings
D2150Specification for Woven Roving Glass Fabric for
1.4 Special design consideration shall be given to tanks
Polyester-Glass Laminates (Withdrawn 1987)
subject to environmental and/or mechanical forces such as
D2583Test Method for Indentation Hardness of Rigid Plas-
seismic, wind, ice, agitation, or fluid dynamic forces, to
tics by Means of a Barcol Impressor
operationalservicetemperaturesgreaterthan180°F(82°C)and
D2584Test Method for Ignition Loss of Cured Reinforced
to tanks with unsupported bottoms.
Resins
1.5 The following safety hazards caveat pertains only to the
D2996 Specification for Filament-Wound “Fiberglass”
test method portion, Section 11, of this specification: This
(Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
standard does not purport to address all of the safety concerns,
D2997Specification for Centrifugally Cast “Fiberglass”
if any, associated with its use. It is the responsibility of the user
(Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
of this standard to establish appropriate safety, health, and
D3892Practice for Packaging/Packing of Plastics
environmental practices and determine the applicability of
D4024SpecificationforMachineMade“Fiberglass”(Glass-
regulatory limitations prior to use.
Fiber-Reinforced Thermosetting Resin) Flanges
NOTE 1—There is no known ISO equivalent to this standard. D5421 Specification for Contact Molded “Fiberglass”
(Glass-Fiber-Reinforced Thermosetting Resin) Flanges
1.6 This international standard was developed in accor-
F412Terminology Relating to Plastic Piping Systems
dance with internationally recognized principles on standard-
1 2
This specification is under the jurisdiction of ASTM Committee D20 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Plastics and is the direct responsibility of Subcommittee D20.23 on Reinforced contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Plastic Piping Systems and Chemical Equipment. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Aug. 1, 2018. Published August 2018. Originally the ASTM website.
approved in 1974. Last previous edition approved in 2010 as D3299–10. DOI: The last approved version of this historical standard is referenced on
10.1520/D3299-18. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3299−18
NOTE 3—The addition of a thixotropic agent may reduce the resistance
2.2 ANSI Standards:
ofmanyresinsystemstocertaincorrosivechemicalenvironments.Itisthe
B16.1 Cast Iron Pipe Flanges and Flanged Fittings, Class
responsibility of the fabricator, using a thixotropic agent in the resin
25, 125, 250, and 800
required for 7.1.1 and 7.1.2, to ascertain its compatibility with the
corrosive environment when this has been reported to him by the
3. Terminology
purchaser.
3.1 General—DefinitionsareinaccordancewithTerminolo-
5.1.1.2 Resinpastesusedtofillcrevicesbeforeoverlayshall
gies D883 and F412, unless otherwise indicated.
not be subject to the limitations of 5.1.1.
3.2 filament-wound—asappliedtotanks,aprocessinwhich 5.1.1.3 Resinmaycontainpigment,dyes,orcolorantswhen
the principal circumferential load-bearing reinforcement is agreed upon between fabricator and purchaser.
applied by continuous filament winding.
NOTE4—Theadditionofpigment,dyes,orcolorantsmayinterferewith
visual inspection of laminate quality.
3.3 contact molding—amoldingprocessthatincludes“hand
lay-up,” “spray-up,” or a combination of these manufacturing
5.1.1.4 Ultraviolet absorbers may be added to the exterior
processes.
surface for improved weather resistance, if agreed upon be-
tween fabricator and purchaser.
4. Classification
5.1.1.5 Antimony compounds or other fire-retardant agents
4.1 Tanksmeetingthisspecificationareclassifiedaccording
may be added to halogenated resins for improved fire
to type as follows, and it is the responsibility of the purchaser
resistance, if agreed upon between fabricator and purchaser.
to specify the requirement for Type II tanks, the operating
NOTE 5—Because the addition of fire-retardant agents may interfere
pressure or vacuum levels, and the safety factor required for
with visual inspection of laminate quality, they should not be used in the
external pressure. Absence of a designation of type required
inner surface (7.1.1) or interior layer (7.1.2) unless their functional
shall imply that Type I is adequate.
advantages would outweigh the loss of visual inspection.
4.1.1 Type I—Atmosphericpressuretanksventeddirectlyto
5.2 Reinforcement:
the atmosphere, designed for pressure no greater or lower than
5.2.1 Chopped-Strand Mat—Chopped-strand mat shall be
atmospheric.
constructed from chopped commercial-grade E-type glass
4.1.2 Type II—Atmospheric pressure tanks vented directly
strands bonded together using a binder. The strands should be
intoafumeconservationsystem,anddesignedtowithstandthe
treated with a sizing that is chemically compatible with the
specified positive and negative pressure not to exceed 14 in.
resin system used.
(355.6 mm) of water when all tie-down lugs are properly
NOTE 6—The selection of the particular chopped-strand mat is depen-
secured, in accordance with the fabricator’s recommendations
dentupontheperformancecharacteristicsrequiredofthefinishedproduct
for flat-bottom tanks.
and upon the processing techniques to be used.
4.2 Tanksmeetingthisspecificationareclassifiedaccording
5.2.2 Continuous Roving—Continuous roving shall be a
to grade as follows:
commercial-grade of E-type glass fiber with a sizing that is
4.2.1 Grade 1—Tanks manufactured with a single generic
chemically compatible with the resin system used.
type of thermoset resin throughout.
5.2.3 Nonwoven Biaxial or Unidirectional Fabric—These
4.2.2 Grade 2—Tanks manufactured with different generic
productsshallbeacommercialGradeofE-typeglassfiberwith
types of thermoset resin in the barrier and the structural
a sizing that is chemically compatible with the resin system
portion.
used.
NOTE 2—The external corrosive environment due to spillage or 5.2.4 Woven Roving—Woven roving shall be in accordance
corrosivevaporsshouldbeconsideredwhenspecifyingGrade2tanks(see
with Specification D2150.
7.1.3.3).
5.2.5 Surface Mat—The reinforcement used for the inner
surface (7.1.1) shall be either a commercial-grade chemical
5. Materials and Manufacture
resistant glass surface mat or an organic-fiber surface mat. In
5.1 Resin—The resin used shall be a commercial-grade,
environments that attack glass, the use of an organic-fiber
corrosion-resistant thermoset that has either been evaluated in
surface mat is required.
a laminate by test in accordance with 11.3 or that has been
determined by previous documented service to be acceptable
6. Design Requirements
for the service conditions. Where service conditions have not
6.1 Filament-Wound Laminates—Design for Internal
been evaluated, a suitable resin also may be selected by
Pressure—The maximum allowable stress of the total laminate
agreement between fabricator and purchaser.
(that is, filament winding plus the corrosion barrier, which is
5.1.1 Theresinshallcontainnopigment,dyes,colorants,or
made up of the inner surface (7.1.1) and interior layer (7.1.2))
filler, except as follows:
shallbelimitedbytheallowablemovement(strain)ofthetank
5.1.1.1 A thixotropic agent that does not interfere with
wall when filled with fluid.
visual inspection of laminate quality, or with the required
6.1.1 The allowable strain of the tank wall shall not exceed
corrosion resistance of the laminate, may be added for viscos-
ity control. 0.0010 in./in. (mm/mm) at 70°F (21°C).
6.1.2 Tanks shall have a longitudinal strength at least equal
to that of a helically wound tank having a maximum angle of
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. wind of 80° (measured from the tank axis, that is, 90° is hoop
D3299−18
2.5
winding). For reference, the longitudinal tensile strength of a 2.6 E/F D /L t/D
~ !~ !~ !
o o
P 5 (4)
a 0.5
typical 80° helical winding is approximately 2200 psi (15,168 ~L/D ! 20.45 ~t/D !
o o
kPa).
where:
6.1.3 Hoop Design:
D = outside diameter, in. (mm),
o
6.1.3.1 Normal Service (Structural Corrosion Barrier)—
E = lowerofhooptensilemodulusoraxialtensilemodulus,
When the product to be stored in the tank causes little or no
psi (kPa),
degradation to the selected resin, the minimum required wall
F = design factor = 5,
thickness shall be in accordance with Eq 1.
L = design length, in., of a vessel section, taken as the
6.1.3.2 Severe Service (Non-Structural Corrosion
largest of the following: (a) the distance between
Barrier)—Whentheproducttobestoredinthetankmaycause
head-tangent lines plus one-third the depth of each
degradation of the resin over time and with the agreement of
formed head if there are no stiffening rings (excluding
thepurchaser,theminimumrequiredwallthicknessofthetank
conical heads and sections); (b) the distance between
shall be determined in accordance with Eq 2.
cone-to-cylinder junctions for vessels with a cone or
conical heads if there are no stiffening rings; (c) the
0.036*γ*H*D
t 5 (1)
T
greatest center-to-center distance between any two
2*E *Z
T
adjacent stiffening rings; (d) the distance from the
or
center of the first stiffening ring to the formed head
tangentlineplusone-thirdthedepthoftheformedhead
0.2489*γ*H*D
(excluding conical heads and sections), all measured
t 5
S D
T
2*E *Z
T
parallel to the axis of the vessel; (e) the distance from
0.036*γ*H*D
the first stiffening ring in the cylinder to the cone-to-
t 5 t 1 (2)
T CB
2*E *Z cylinder junction,
FW
P = allowable external pressure, psi (kPa), and
a
or
t = wall thickness, in. (mm) (nominal).
6.2.2 Torispherical Heads—For torispherical heads, com-
0.2489*γ*H*D
t 5 t 1
S D
T CB
pute the allowable external pressure P as follows:
2*E *Z a
FW
P 50.36 E/F t/R (5)
~ !~ !
a o
where:
t = total thickness, in. (mm), where:
T
t = thickness of the corrosion barrier, in. (mm),
CB
R = outside crown radius of head, in. (mm).
o
H = fluid head, in. (mm),
6.2.2.1 For torispherical heads subject to internal loading,
γ = specific gravity of fluid,
the knucle radius shall be externally reinforced in accordance
D = inside diameter of tank, in. (mm).
with Fig. 1. The reinforcement thickness shall be equal to the
E = hoop tensile modulus of the total laminate (see
T
thickness of the head as calculated above. The thickness of a
Appendix X3), psi (kPa),
joint overlay near the knucle radius tangent line of a dished
E = hooptensilemodulusofthefilamentwindingonlypsi
FW
(kPa), and head contributes to the knucle reinforcement.
Z = allowable strain in accordance with 6.1.2.
6.1.3.3 The minimum total thickness of the tank shall be
0.1875 in. (4.76 mm).
NOTE7—Theuseofanacceptedanalyticaltechnique,suchaslaminated
plate theory (LPT), for design and analysis of composite vessels may
predict stresses, strains, and strength on a ply-by-ply basis, given some
basic lamina properties.
NOTE8—Tanksforinstallationoutdoorsshallbedesignedfortheeffect
ofwindloadingandotherenvironmentalfactorsinaccordancewithsound
design practice, including tank buckling analysis.
NOTE 9—Tanks with significant physical loadings other than fluid head
(such as side-mounted equipment, violent agitation, unusually high flow
rates, and unsupported bottoms) shall be given special design consider-
ation.
6.2 Design for External Pressure:
6.2.1 Cylindrical Shells—For cylindrical shell, compute the
0.5
value 1.73 (D /t) . If the result is less than L/D of the
o o
cylinder, compute P as follows:
a
2.5
P 52.6 E/F D /L t/D (3)
~ !~ !~ !
a o o
If the result is greater than L/D of the cylinder, compute P
o a FIG. 1Jointed Head Detail
as follows: Sketch A
D3299−18
6.2.3 Stiffening Rings—The required moment of inertia, I , mm) for over 6 to 12 ft (1.8 to 3.7 m) diameter, and ⁄8 in. (9.5
s
of a circumferential stiffening ring for cylindrical shells under mm) for over 12 ft (3.7 m) diameter.
external pressure or internal vacuum shall not be less than that
6.3.2.1 Deflectionoftheflatbottomwhenthetankisempty,
determined by the following formula:
commonly known as “oil canning,” is permissible as long as
the requirements of 6.3.2.4 are met.
I 5 PL D F/24E (6)
s s o h
6.3.2.2 Bottom heads may be molded integrally with the
where:
straight shell or may be molded separately with a straight
D = shell outside diameter, in. (mm),
o
flange length for subsequent joining to shell.
E = hoop tensile modulus, psi (kPa),
h
6.3.2.3 The radius of the bottom knuckle of a flat-bottom
F = design factor = 5,
4 4
tank shall be not less than 1 in. (25 mm) on tanks 4 ft (1.22 m)
I = momentofinertia,in. (mm ),ofstiffenerandeffective
s
orsmallerindiameterand1.5in.(38mm)ontankslargerthan
length of shell,
4 ft (1.22 m) diameter.The minimum thickness of the radiused
L = one-half of the distance from the centerline of the
s
section shall be equal to the combined thickness of the shell
stiffening ring to the next line of support on one side,
wall and the bottom. The reinforcement of the knuckle-radius
plus one-half of the centerline distance to the next line
area shall taper so that it is tangent to the flat bottom, and shall
of support on the other side of the stiffening ring, both
notextendbeyondthetangentlineontothetankbottom,unless
measured parallel to the axis of the cylinder, in.Aline
methods of manufacture are used that maintain flat-bottom
of support is the following: (a) a stiffening ring that
configuration, and shall extend up the vertical tank wall a
meetstherequirementsofthisparagraph;(b)acircum-
minimum of 8 in. (200 mm) on tanks up to 4 ft (1.22 m) in
ferential line on a head at one-third the depth of the
diameter, and 12 in. (304 mm) on tanks over 4 ft (1.22 m) in
head from the head tangent line; (c) a cone-to-cylinder
diameter. The reinforcement shall then taper into the side wall
junction, and
over an additional length of 4 in. (102 mm) (see Fig. 3).
P = actual external pressure, psi (kPa).
Methods of manufacture that incorporate stiffening bands as a
Typical half-round stiffener sizes and dimensions for differ-
means of knuckle stabilization, are permissible alternatives by
ent values of I are shown in Fig. 2. Other stiffener profiles
s
agreement between purchaser and fabricator, provided the
meeting the required moment of inertia may be used.
fabricator can document the validity of the design.
6.3 Contact Molded Laminates—Portions of the tank, such
6.3.2.4 The tank bottom shall not have variations from a
as joints, heads, nozzles, and supports, may be fabricated by
nominally flat plane that would prevent uniform contact of the
contact molding. Contact-molded laminates shall satisfy the
entire bottom surface with a properly prepared flat support
minimum property requirements listed in Specification C582,
surfacewhenthetankisfilledwithliquid.Thebottomlaminate
as shown in Table 1.
surface shall be a hand-work finish, and shall have no exces-
6.3.1 Top Head—Thetophead,regardlessofshape,shallbe
sive laminate projections that would prevent uniform contact
able to support a single 250-lbf (113.4 kg) load ona4by 4-in.
with a properly prepared flat support surface when the tank is
(100 by 100-mm) area without damage and with a maximum
filled with liquid.
deflection of ⁄2% of the tank diameter at the area the load is
NOTE 11—This requirement is not intended to exclude the use of drain
applied.
nozzleswhicharecommonlyusedatthebottomofthesideshell.Theydo,
6.3.1.1 The minimum thickness shall be 0.1876 in. (4.76
however,requirefoundationcut-outsoftheappropriatedimensionsforthe
mm).
nozzle type and size.
NOTE 10—Support of auxiliary equipment, snow load, or operation
6.3.2.5 The thickness of an elevated torispherical dished
personnelmayrequireadditionalreinforcementortheuseofstiffenerribs,
bottom, suitable for supporting the weight of the fluid head,
sandwichconstruction,orotherstiffeningsystems.TypeIItanksmayalso
shall be determined by the following equation, but shall not be
require additional reinforcement.
less than ⁄16 in. (4.8 mm):
6.3.2 Bottom Head—The minimum thickness for a fully
supportedflat-bottomheadforTypeItanksshallbeasfollows: 0.885 PR 0.885 ~0.036γHR! 0.885 ~0.2489γHR!
t 5 5 or (7)
S D
3 1
⁄16in.(4.8mm)for2to6ft(0.6to1.8m)diameter, ⁄4in.(6.4 S S S
D3299−18
FIG. 2 Penetrating Nozzle Installation
A
TABLE 1 Minimum Contact-Molded Laminate Physical Properties
NOTE 1— Based on use of woven roving in thickness ⁄4 in. (6mm) and above.
Property Thickness, in. (mm)
1 3 1 5 3
⁄8 to ⁄16 (3.2 to 4.8) ⁄4 (6.4) ⁄16 (7.9) ⁄8 & up (9.5 and up)
Ultimate tensile strength, min, psi (MPa) 9 000 (62.05) 12 000 (82.74) 13 000 (89.63) 15 000 (103.4)
Tensile modulus, psi (MPa) 1 000 000 (6895) 1 300 000 (8963) 1 400 000 (9653) 1 500 000 (10342)
Flexural strength, min, psi (MPa) 16 000 (110.3) 19 000 (131.0) 20 000 (137.9) 22 000 (151.7)
Flexural modulus of elasticity (tangent), min, psi 700 000 (4826) 800 000 (5516) 900 000 (6205) 1 000 000 (6894)
(MPa)
A
LaminatesthatdonotmeettheminimumvaluesofTable1areconsideredacceptable,providedtheyaremadetoaffordthesameoverallstrengththatwouldbeobtained
with a laminate meeting the specified thickness.
where: PD
t 5 (8)
2S
t = thickness, in. (mm),
S = allowable tensile strength (not to exceed ⁄10 of ultimate
For Cone Bottom:
strength), psi (kPa) (see 11.6.1),
PD
γ = specific gravity of fluid,
t 5 (9)
P = pressure, psi (kPa),
2S· cos α
~ !
R = inside radius of dished head, in. (mm), and
where:
H = distance from the top of the fluid to the deepest portion
α = ⁄2theincluded(apex)angleoftheconeatthecenterline
of the bottom, in. (mm).
of the head. ( Not greater than 30°)
For Elliptical Bottom Head:
D3299−18
FIG. 3 Flat-Bottom Tank Corner Detail
NOTE12—Analternativemethodfordesignofanelevatedtorispherical
6.3.3 Open-Top Tanks—The top edge of open-top tanks
dished bottom is shown in Appendix X2.
shall have a horizontal reinforcing flange or other means of
6.3.2.6 The torispherical dished-bottom head shall have a reinforcement sufficiently rigid to maintain the shape of the
radius of curvature that is equal to or less than the inside tankafterinstallation,suchasstiffenerribs.Theflangeshallbe
diameter of the tank straight shell, and a minimum knuckle in accordance with Table 2.
radius of at least 6% of the diameter of the head. 6.3.4 Joints:
A,B
TABLE 2 Reinforcing Flange for Open-Top Tanks
Tank Diameter, ft (m) Flange Dimensions
Flange
C D
L, ft (m) Width Thickness
2 4 6 8 9 10 11 12
Type
(0.610) (1.219) (1.629) (2.438) (2.743) (3.048) (3.353) (3.658)
in. (mm) in. (mm)
2 (0.610) A A A C D E F G A 2 (51) ⁄4 (5)
4 (1.212) A A A C D E F G B 2 (51) ⁄8 (10)
6 (1.829) A A A C D E F G C 2 (51) ⁄2 (13)
1 3
8 (2.438) A A A C D E F G D 2 ⁄2 (64) ⁄8 (10)
1 1
10 (3.048) A A B C D E F G E 2 ⁄2 (64) ⁄2 (13)
12 (3.658) A A B D D E F G F 3 (76) ⁄8 (10)
14 (4.267) A A B D E F F G G 3 (76) ⁄2 (13)
16 (4.877) A A C E E G G H H 3 (76) ⁄8 (16)
18 (5.486) A A C E F G G H J 3 (76) ⁄4 (19)
20 (6.096) A A D E F G H J K 3 (76) 1 (25)
24 (7.315) A B D F G H J K
30 (9.144) A B E G H H K K
36 (10.973) A B E H J K K
40 (12.192) A B E H J K
A
This table is based on handling considerations only. Significant superimposed loads, such as from wind or seismic conditions, should be considered independently.
B
Reinforcement configurations other than a flange may be used if equal or greater stiffness is provided.
C
L = maximum distance from flange to the tank bottom or to the uppermost shell stiffener when used.
D
Flange thickness shall be at least equal to local vessel thickness.
D3299−18
6.3.4.1 The cured resin surfaces to be overlaid shall be overlay width shall be 4 in. (100 mm). This internal overlay
roughened using 36 or coarser grit abrasive media and shall shall not be considered a structural element in determining
extend beyond the lay-up area so that no reinforcement is joint thickness.
applied to an unroughened surface. Surfaces shall be clean and
6.3.4.5 The thickness of a joint near the bottom tangent line
dry before lay-up. The entire roughened area shall be coated
shall not be considered to contribute to the knuckle reinforce-
with paraffinated resin after the joint lay-up is made.
ment of 6.3.2.3, but shall be additive thereto.
6.3.4.2 Joints between tank-wall sections shall be over-
6.3.5 Fittings:
wound to a thickness as calculated in 6.1.3.2, or they may be
6.3.5.1 The more common method of fabricating nozzles is
overlaid by a contact-molded laminate. When contact-molded
by contact molding both the nozzle neck and flange to the
laminate joints are used to join hoop segments of the straight
dimensions shown in Specification D5421 and Table 4. The
shell, or to join the bottom or top head to the shell, the
corrosion-resistant barrier of the nozzle shall be at least
thickness of the structural joint overlay shall be determined by
equivalent to the inner surface and interior layer (7.1.1 and
the following equation, but shall not be less than ⁄16 in. (4.8
7.1.2) and shall be fabricated from the same resin as the tank
mm):
head or shell to which it is attached.
PD 0.036γHD 0.2489γHD
6.3.5.2 Acceptable alternative methods to be agreed upon
t 5 5 or (10)
S D
2S 2S 2S
h h h
betweenfabricatorandpurchaseraretheuseofcontact-molded
where: pipe, filament-wound pipe, in accordance with Specification
D2996, or centrifugally cast pipe, in accordance with Specifi-
t = wall thickness, in. (mm),
cation D2997, joined to a suitable contact-molded (Specifica-
S = allowablehooptensilestrength(nottoexceed ⁄10ofthe
h
tion D5421), or filament-wound flange (Specification D4024).
ultimate hoop strength), psi (kPa),
P = pressure, psi (kPa), The corrosion-resistant barrier of the contact-molded portions
H = fluid head, in. (mm),
of such nozzles shall be equivalent to the inner surface and
γ = specific gravity of fluid, and
interior layer (7.1.1 and 7.1.2) and shall be fabricated from the
D = inside diameter of tank, in. (mm).
sameresinasthetankheadorshelltowhichtheyareattached.
6.3.4.3 The minimum width of the structural joint overlay 6.3.5.3 Nozzles 4 in. (100 mm) and smaller shall be
for bottom-supported tanks is shown in Table 3. supportedbyasuitablegussetingtechnique,usingplategussets
6.3.4.4 The corrosion-resistant barrier component of the or conical gussets, as shown in Fig. 4 and Fig. 5. Plate gussets,
joint shall be formed in the same manner as the inner surface where needed, shall be evenly spaced around the nozzle and
and the interior layer (7.1.1 and 7.1.2) and the minimum are to be added after complete assembly by the nozzle on the
TABLE 3 Minimum Widths of Joint Overlay for Circumferential Joints
A
H × D = 60 100 140 180 220 260 300 340 380 420 460 500
minimum
width of
B
outside
in. 445678910 11 12 13 14
(mm) (102) (102) (127) (152) (178) (203) (229) (254) (279) (305) (330) (356)
A
where: H = distance from the top of the liquid level to the joint, ft (m) and
D = inside diameter of the tank, ft (m).
B
Axial joint overlay widths shall be twice the width shown in table.
D3299−18
TABLE 4 Dimensions for Contact-Molded Flanged Nozzles (25 psi Rating)
Nozzle Inside Minimum Wall Minimum Flange Minimum Hub Minimum Hub Length
Diameter (D), in. (mm) Thickness (t ), Thickness (t), in. Thickness (t ), (h), in. (mm)
n f h
in. (mm) (mm) in. (mm)
3 1 1
1 (25) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
1 3 1 1
1 ⁄2 (38) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 1 1
2 (51) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 1 1
3 (76) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 1 1
4 (102) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 1 1
6 (152) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 9 5 1
8 (203) ⁄16 (5) ⁄16 (14) ⁄16 (8) 2 ⁄2 (57)
3 11 3 3
10 (254) ⁄16 (5) ⁄16 (17) ⁄8 (10) 2 ⁄4 (70)
3 3 3
12 (305) ⁄16 (5) ⁄4 (19) ⁄8 (10) 3 (76)
1 13 7 1
14 (356) ⁄4 (6) ⁄16 (21) ⁄16 (11) 3 ⁄4 (83)
1 7 7 1
16 (406) ⁄4 (6) ⁄8 (22) ⁄16 (11) 3 ⁄2 (89)
1 15 1 3
18 (457) ⁄4 (6) ⁄16 (24) ⁄2 (13) 3 ⁄4 (95)
1 1
20 (508) ⁄4 (6) 1 (25) ⁄2 (13) 4 (102)
1 1 9 1
24 (610) ⁄4 (6) 1 ⁄8 (29) ⁄16 (14) 4 ⁄2 (114)
FIG. 4 Plate-Type Gussets
shell. Larger nozzles, subject to superimposed mechanical
forces, require special consideration.
D3299−18
NOTE 1—This design does not require lay-up of nozzle neck to exterior of tank wall. Nozzle may be penetrating type or flush type as illustrated.
FIG. 5Conical Type Gussets
NOTE 13—Tanks over 6 ft (1.8 m) straight-shell height may need both
6.3.5.4 Manways installed in top heads may be of the
top- and side-shell opening manways for safety and maintenance consid-
flanged or nonflanged design, as agreed upon between the
erations.
fabricator and purchaser.
6.4 Vents:
6.3.5.5 Side-shell manways shall be installed in accordance
with 7.3.2, 7.3.3, and Fig. 6. 6.4.1 Vents that discharge freely into the atmosphere must
6.3.5.6 Typical manway dimensions are shown in Table 5. be provided in all Type I closed-top tanks. Minimum vent size
NOTE 1—This installation method is used only when the nozzle is being installed with an integral conical gusset which would prevent application of
an exterior laminate.
FIG. 6Nozzle Installation and Cutout Reinforcement Location Alternative
D3299−18
TABLE 5 Typical Dimensions of Manways
NOTE 1—Bolt size equals bolt hole diameter minus ⁄8 in. (3 mm).
NOTE 2—Gaskets shall be ⁄8 in. thick full-face elastomeric material having a hardness of Shore A80 ± 5.
Minimum Minimum Diameter of Minimum Thickness of Minimum Manway Diameter of Bolt Number of Bolt Hole Diameter, in.
ABC
Size, in. Flange and Cover, in. Flange and Cover, in. Wall Thickness, in. Circle, in. (mm) Bolts (mm)
(mm) (mm) (mm) (mm)
Pressurized Manway—up to 15 psig
1 3 3
20 (508) 27 ⁄2 (699) 1 (25.4) ⁄8 (9.5) 25 (635) 20 ⁄4 (19)
3 3
22 (559) 30 (762) 1 (25.4) ⁄8 (9.5) 27 (686) 20 ⁄4 (19
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3299 − 10 D3299 − 18 An American National Standard
Standard Specification for
Filament-Wound Glass-Fiber-Reinforced Thermoset Resin
Corrosion-Resistant Tanks
This standard is issued under the fixed designation D3299; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This specification covers cylindrical tanks fabricated by filament winding for above-ground vertical installation, to contain
aggressive chemicals at atmospheric pressure as classified herein, and made of a commercial-grade polyester or vinylester resin.
Included are requirements for materials, properties, design, construction, dimensions, tolerances, workmanship, and appearance.
1.2 This specification does not cover the design of vessels intended for pressure above atmospheric, atmospheric or under
vacuum conditions, except as classified herein, or vessels intended for use with liquids heated above their flash points.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
NOTE 1—Special design consideration should be given to vessels subject to superimposed mechanical forces, such as earthquakes, wind load, or
agitation, and to vessels subject to service temperature in excess of 180°F (82°C), and to vessels with unsupported bottoms.
NOTE 2—There is no similar or equivalent ISO standard.
1.4 Special design consideration shall be given to tanks subject to environmental and/or mechanical forces such as seismic,
wind, ice, agitation, or fluid dynamic forces, to operational service temperatures greater than 180°F (82°C) and to tanks with
unsupported bottoms.
1.5 The following safety hazards caveat pertains only to the test method portion, Section 11, of this specification: This standard
does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this
standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the applicability of
regulatory limitations prior to use.
NOTE 1—There is no known ISO equivalent to this standard.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C581 Practice for Determining Chemical Resistance of Thermosetting Resins Used in Glass-Fiber-Reinforced Structures
Intended for Liquid Service
C582 Specification for Contact-Molded Reinforced Thermosetting Plastic (RTP) Laminates for Corrosion-Resistant Equipment
D618 Practice for Conditioning Plastics for Testing
D883 Terminology Relating to Plastics
D1599 Test Method for Resistance to Short-Time Hydraulic Pressure of Plastic Pipe, Tubing, and Fittings
D2150 Specification for Woven Roving Glass Fabric for Polyester-Glass Laminates (Withdrawn 1987)
D2583 Test Method for Indentation Hardness of Rigid Plastics by Means of a Barcol Impressor
This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.23 on Reinforced Plastic Piping
Systems and Chemical Equipment.
Current edition approved April 1, 2010Aug. 1, 2018. Published May 2010August 2018. Originally approved in 1974. Last previous edition approved in 20082010 as
D3299 – 08.D3299 – 10. DOI: 10.1520/D3299-10.10.1520/D3299-18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3299 − 18
D2584 Test Method for Ignition Loss of Cured Reinforced Resins
D2996 Specification for Filament-Wound “Fiberglass” (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
D2997 Specification for Centrifugally Cast “Fiberglass” (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
D3892 Practice for Packaging/Packing of Plastics
D4024 Specification for Machine Made “Fiberglass” (Glass-Fiber-Reinforced Thermosetting Resin) Flanges
D5421 Specification for Contact Molded “Fiberglass” (Glass-Fiber-Reinforced Thermosetting Resin) Flanges
F412 Terminology Relating to Plastic Piping Systems
2.2 ANSI Standards:
B 16.1 Cast Iron Pipe Flanges and Flanged Fittings, Class 25, 125, 250, and 800
3. Terminology
3.1 General—Definitions are in accordance with Terminologies D883 and F412, unless otherwise indicated.
3.2 filament-wound—as applied to tanks, a process in which the principal circumferential load-bearing reinforcement is applied
by continuous filament winding.
3.3 contact molding—a molding process that includes “hand lay-up,” “spray-up,” or a combination of these manufacturing
processes.
4. Classification
4.1 Tanks meeting this specification are classified according to type as follows, and it is the responsibility of the purchaser to
specify the requirement for Type II tanks, the operating pressure or vacuum levels, and the safety factor required for external
pressure. Absence of a designation of type required shall imply that Type I is adequate.
4.1.1 Type I—Atmospheric pressure tanks vented directly to the atmosphere, designed for pressure no greater or lower than
atmospheric.
4.1.2 Type II—Atmospheric pressure tanks vented directly into a fume conservation system, and designed to withstand the
specified positive and negative pressure not to exceed 14 in. (355.6 mm) of water when all tie-down lugs are properly secured,
in accordance with the fabricator’s recommendations for flat-bottom tanks.
4.2 Tanks meeting this specification are classified according to grade as follows:
4.2.1 Grade 1—Tanks manufactured with a single generic type of thermoset resin throughout.
4.2.2 Grade 2—Tanks manufactured with different generic types of thermoset resin in the barrier and the structural portion.
NOTE 2—The external corrosive environment due to spillage or corrosive vapors should be considered when specifying Grade 2 tanks (see 7.1.3.3).
5. Materials and Manufacture
5.1 Resin—The resin used shall be a commercial-grade, corrosion-resistant thermoset that has either been evaluated in a
laminate by test in accordance with 11.3 or that has been determined by previous documented service to be acceptable for the
service conditions. Where service conditions have not been evaluated, a suitable resin also may be selected by agreement between
fabricator and purchaser.
5.1.1 The resin shall contain no pigment, dyes, colorants, or filler, except as follows:
5.1.1.1 A thixotropic agent that does not interfere with visual inspection of laminate quality, or with the required corrosion
resistance of the laminate, may be added for viscosity control.
NOTE 3—The addition of a thixotropic agent may reduce the resistance of many resin systems to certain corrosive chemical environments. It is the
responsibility of the fabricator, using a thixotropic agent in the resin required for 7.1.1 and 7.1.2, to ascertain its compatibility with the corrosive
environment when this has been reported to him by the purchaser.
5.1.1.2 Resin pastes used to fill crevices before overlay shall not be subject to the limitations of 5.1.1.
5.1.1.3 Resin may contain pigment, dyes, or colorants when agreed upon between fabricator and purchaser.
NOTE 4—The addition of pigment, dyes, or colorants may interfere with visual inspection of laminate quality.
5.1.1.4 Ultraviolet absorbers may be added to the exterior surface for improved weather resistance, if agreed upon between
fabricator and purchaser.
5.1.1.5 Antimony compounds or other fire-retardant agents may be added to halogenated resins for improved fire resistance, if
agreed upon between fabricator and purchaser.
NOTE 5—Because the addition of fire-retardant agents may interfere with visual inspection of laminate quality, they should not be used in the inner
surface (7.1.1) or interior layer (7.1.2) unless their functional advantages would outweigh the loss of visual inspection.
5.2 Reinforcement:
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
D3299 − 18
5.2.1 Chopped-Strand Mat—Chopped-strand mat shall be constructed from chopped commercial-grade E-type glass strands
bonded together using a binder. The strands should be treated with a sizing that is chemically compatible with the resin system
used.
NOTE 6—The selection of the particular chopped-strand mat is dependent upon the performance characteristics required of the finished product and
upon the processing techniques to be used.
5.2.2 Continuous Roving—Continuous roving shall be a commercial-grade of E-type glass fiber with a sizing that is chemically
compatible with the resin system used.
5.2.3 Nonwoven Biaxial or Unidirectional Fabric—These products shall be a commercial Grade of E-type glass fiber with a
sizing that is chemically compatible with the resin system used.
5.2.4 Woven Roving—Woven roving shall be in accordance with Specification D2150.
5.2.5 Surface Mat—The reinforcement used for the inner surface (7.1.1) shall be either a commercial-grade chemical resistant
glass surface mat or an organic-fiber surface mat. In environments that attack glass, the use of an organic-fiber surface mat is
required.
6. Design Requirements
6.1 Filament-Wound Laminates—Design for Internal Pressure—The maximum allowable stress of the total laminate (that is,
filament winding plus the corrosion barrier, which is made up of the inner surface (7.1.1) and interior layer (7.1.2)) shall be limited
by the allowable movement (strain) of the tank wall when filled with fluid.
6.1.1 The allowable strain of the tank wall shall not exceed 0.0010 in./in. (mm/mm) at 70°F (21°C).
6.1.2 Tanks shall have a longitudinal strength at least equal to that of a helically wound tank having a maximum angle of wind
of 80° (measured from the tank axis, that is, 90° is hoop winding). For reference, the longitudinal tensile strength of a typical 80°
helical winding is approximately 2200 psi (15,168 kPa).
6.1.3 Hoop Design:
6.1.3.1 Normal Service (Structural Corrosion Barrier)—When the product to be stored in the tank causes little or no degradation
to the selected resin, the minimum required wall thickness shall be in accordance with Eq 1.
6.1.3.2 Severe Service (Non-Structural Corrosion Barrier)—When the product to be stored in the tank may cause degradation
of the resin over time and with the agreement of the purchaser, the minimum required wall thickness of the tank shall be determined
in accordance with Eq 2.
0.036*γ*H*D
t 5 (1)
T
2*E *Z
T
or
0.2489*γ*H*D
t 5
S D
T
2*E *Z
T
0.036*γ*H*D
t 5 t 1 (2)
T CB
2*E *Z
FW
or
0.2489*γ*H*D
t 5 t 1
S D
T CB
2*E *Z
FW
where:
t = total thickness, in. (mm),
T
t = thickness of the corrosion barrier, in. (mm),
CB
H = fluid head, in. (mm),
γ = specific gravity of fluid,
D = inside diameter of tank, in. (mm).
E = hoop tensile modulus of the total laminate (see Appendix X3), psi (kPa),
T
E = hoop tensile modulus of the filament winding only psi (kPa), and
FW
Z = allowable strain in accordance with 6.1.2.
6.1.3.3 The minimum total thickness of the tank shall be 0.1875 in. (4.76 mm).
NOTE 7—The use of an accepted analytical technique, such as laminated plate theory (LPT), for design and analysis of composite vessels may predict
stresses, strains, and strength on a ply-by-ply basis, given some basic lamina properties.
NOTE 8—Tanks for installation outdoors shall be designed for the effect of wind loading and other environmental factors in accordance with sound
design practice, including tank buckling analysis.
NOTE 9—Tanks with significant physical loadings other than fluid head (such as side-mounted equipment, violent agitation, unusually high flow rates,
and unsupported bottoms) shall be given special design consideration.
D3299 − 18
6.2 Design for External Pressure:
0.5
6.2.1 Cylindrical Shells—For cylindrical shell, compute the value 1.73 (D /t) . If the result is less than L/D of the cylinder,
o o
compute P as follows:
a
2.5
P 5 2.6~E/F!~D /L!~t/D ! (3)
a o o
If the result is greater than L/D of the cylinder, compute P as follows:
o a
2.5
2.6~E/F!~D /L!~t/D !
o o
P 5 (4)
0.5
a
L/D 2 0.45 t/D
~ ! ~ !
o o
where:
D = outside diameter, in. (mm),
o
E = lower of hoop tensile modulus or axial tensile modulus, psi (kPa),
F = design factor = 5,
L = design length, in., of a vessel section, taken as the largest of the following: (a) the distance between head-tangent lines plus
one-third the depth of each formed head if there are no stiffening rings (excluding conical heads and sections); (b) the
distance between cone-to-cylinder junctions for vessels with a cone or conical heads if there are no stiffening rings; (c) the
greatest center-to-center distance between any two adjacent stiffening rings; (d) the distance from the center of the first
stiffening ring to the formed head tangent line plus one-third the depth of the formed head (excluding conical heads and
sections), all measured parallel to the axis of the vessel; (e) the distance from the first stiffening ring in the cylinder to the
cone-to-cylinder junction,
P = allowable external pressure, psi (kPa), and
a
t = wall thickness, in. (mm) (nominal).
6.2.2 Torispherical Heads—For torispherical heads, compute the allowable external pressure P as follows:
a
P 5 0.36 E/F t/R (5)
~ !~ !
a o
where:
R = outside crown radius of head, in. (mm).
o
6.2.2.1 For torispherical heads subject to internal loading, the knucle radius shall be externally reinforced in accordance with
Fig. 1. The reinforcement thickness shall be equal to the thickness of the head as calculated above. The thickness of a joint overlay
near the knucle radius tangent line of a dished head contributes to the knucle reinforcement.
6.2.3 Stiffening Rings—The required moment of inertia, I , of a circumferential stiffening ring for cylindrical shells under
s
external pressure or internal vacuum shall not be less than that determined by the following formula:
I 5 PL D F/24E (6)
s s o h
where:
D = shell outside diameter, in. (mm),
o
E = hoop tensile modulus, psi (kPa),
h
F = design factor = 5,
FIG. 1 Jointed Head Detail
Sketch A
D3299 − 18
4 4
I = moment of inertia, in. (mm ), of stiffener and effective length of shell,
s
L = one-half of the distance from the centerline of the stiffening ring to the next line of support on one side, plus one-half of
s
the centerline distance to the next line of support on the other side of the stiffening ring, both measured parallel to the axis
of the cylinder, in. A line of support is the following: (a) a stiffening ring that meets the requirements of this paragraph;
(b) a circumferential line on a head at one-third the depth of the head from the head tangent line; (c) a cone-to-cylinder
junction, and
P = actual external pressure, psi (kPa).
Typical half-round stiffener sizes and dimensions for different values of I are shown in Fig. 2. Other stiffener profiles meeting
s
the required moment of inertia may be used.
6.3 Contact Molded Laminates—Portions of the tank, such as joints, heads, nozzles, and supports, may be fabricated by contact
molding. Contact-molded laminates shall satisfy the minimum property requirements listed in Specification C582, as shown in
Table 1.
6.3.1 Top Head—The top head, regardless of shape, shall be able to support a single 250-lbf (113.4 kg) load on a 4 by 4-in. (100
by 100-mm) area without damage and with a maximum deflection of ⁄2 % of the tank diameter at the area the load is applied.
6.3.1.1 The minimum thickness shall be 0.1876 in. (4.76 mm).
NOTE 10—Support of auxiliary equipment, snow load, or operation personnel may require additional reinforcement or the use of stiffener ribs, sandwich
construction, or other stiffening systems. Type II tanks may also require additional reinforcement.
6.3.2 Bottom Head—The minimum thickness for a fully supported flat-bottom head for Type I tanks shall be as follows: ⁄16 in.
1 3
(4.8 mm) for 2 to 6 ft (0.6 to 1.8 m) diameter, ⁄4 in. (6.4 mm) for over 6 to 12 ft (1.8 to 3.7 m) diameter, and ⁄8 in. (9.5 mm)
for over 12 ft (3.7 m) diameter.
FIG. 2 Penetrating Nozzle Installation
D3299 − 18
A
TABLE 1 Minimum Contact-Molded Laminate Physical Properties
NOTE 1— Based on use of woven roving in thickness ⁄4 in. (6mm) and above.
Property Thickness, in. (mm)
1 3 1 5 3
⁄8 to ⁄16 (3.2 to 4.8) ⁄4 (6.4) ⁄16 (7.9) ⁄8 & up (9.5 and up)
Ultimate tensile strength, min, psi (MPa) 9 000 (62.05) 12 000 (82.74) 13 000 (89.63) 15 000 (103.4)
Tensile modulus, psi (MPa) 1 000 000 (6895) 1 300 000 (8963) 1 400 000 (9653) 1 500 000 (10342)
Flexural strength, min, psi (MPa) 16 000 (110.3) 19 000 (131.0) 20 000 (137.9) 22 000 (151.7)
Flexural modulus of elasticity (tangent), min, psi 700 000 (4826) 800 000 (5516) 900 000 (6205) 1 000 000 (6894)
(MPa)
A
Laminates that do not meet the minimum values of Table 1 are considered acceptable, provided they are made to afford the same overall strength that would be obtained
with a laminate meeting the specified thickness.
6.3.2.1 Deflection of the flat bottom when the tank is empty, commonly known as “oil canning,” is permissible as long as the
requirements of 6.3.2.4 are met.
6.3.2.2 Bottom heads may be molded integrally with the straight shell or may be molded separately with a straight flange length
for subsequent joining to shell.
6.3.2.3 The radius of the bottom knuckle of a flat-bottom tank shall be not less than 1 in. (25 mm) on tanks 4 ft (1.22 m) or
smaller in diameter and 1.5 in. (38 mm) on tanks larger than 4 ft (1.22 m) diameter. The minimum thickness of the radiused section
shall be equal to the combined thickness of the shell wall and the bottom. The reinforcement of the knuckle-radius area shall taper
so that it is tangent to the flat bottom, and shall not extend beyond the tangent line onto the tank bottom, unless methods of
manufacture are used that maintain flat-bottom configuration, and shall extend up the vertical tank wall a minimum of 8 in. (200
mm) on tanks up to 4 ft (1.22 m) in diameter, and 12 in. (304 mm) on tanks over 4 ft (1.22 m) in diameter. The reinforcement
shall then taper into the side wall over an additional length of 4 in. (102 mm) (see Fig. 3). Methods of manufacture that incorporate
stiffening bands as a means of knuckle stabilization, are permissible alternatives by agreement between purchaser and fabricator,
provided the fabricator can document the validity of the design.
FIG. 3 Flat-Bottom Tank Corner Detail
D3299 − 18
6.3.2.4 The tank bottom shall not have variations from a nominally flat plane that would prevent uniform contact of the entire
bottom surface with a properly prepared flat support surface when the tank is filled with liquid. The bottom laminate surface shall
be a hand-work finish, and shall have no excessive laminate projections that would prevent uniform contact with a properly
prepared flat support surface when the tank is filled with liquid.
NOTE 11—This requirement is not intended to exclude the use of drain nozzles which are commonly used at the bottom of the side shell. They do,
however, require foundation cut-outs of the appropriate dimensions for the nozzle type and size.
6.3.2.5 The thickness of an elevated torispherical dished bottom, suitable for supporting the weight of the fluid head, shall be
determined by the following equation, but shall not be less than ⁄16 in. (4.8 mm):
0.885 PR 0.885 0.036γHR 0.885 0.2489γHR
~ ! ~ !
t 5 5 or (7)
S D
S S S
where:
t = thickness, in. (mm),
S = allowable tensile strength (not to exceed ⁄10 of ultimate strength), psi (kPa) (see 11.6.1),
γ = specific gravity of fluid,
P = pressure, psi (kPa),
R = inside radius of dished head, in. (mm), and
H = distance from the top of the fluid to the deepest portion of the bottom, in. (mm).
For Elliptical Bottom Head:
PD
t 5 (8)
2S
For Cone Bottom:
PD
t 5 (9)
2S· cos α
~ !
where:
α = ⁄2 the included (apex) angle of the cone at the centerline of the head. ( Not greater than 30°)
NOTE 12—An alternative method for design of an elevated torispherical dished bottom is shown in Appendix X2.
6.3.2.6 The torispherical dished-bottom head shall have a radius of curvature that is equal to or less than the inside diameter
of the tank straight shell, and a minimum knuckle radius of at least 6 % of the diameter of the head.
6.3.3 Open-Top Tanks—The top edge of open-top tanks shall have a horizontal reinforcing flange or other means of
reinforcement sufficiently rigid to maintain the shape of the tank after installation, such as stiffener ribs. The flange shall be in
accordance with Table 2.
6.3.4 Joints:
6.3.4.1 The cured resin surfaces to be overlaid shall be roughened using 36 or coarser grit abrasive media and shall extend
beyond the lay-up area so that no reinforcement is applied to an unroughened surface. Surfaces shall be clean and dry before
lay-up. The entire roughened area shall be coated with paraffinated resin after the joint lay-up is made.
A,B
TABLE 2 Reinforcing Flange for Open-Top Tanks
Tank Diameter, ft (m) Flange Dimensions
Flange
C D
L, ft (m) Width Thickness
2 4 6 8 9 10 11 12
Type
(0.610) (1.219) (1.629) (2.438) (2.743) (3.048) (3.353) (3.658)
in. (mm) in. (mm)
2 (0.610) A A A C D E F G A 2 (51) ⁄4 (5)
4 (1.212) A A A C D E F G B 2 (51) ⁄8 (10)
6 (1.829) A A A C D E F G C 2 (51) ⁄2 (13)
1 3
8 (2.438) A A A C D E F G D 2 ⁄2 (64) ⁄8 (10)
1 1
10 (3.048) A A B C D E F G E 2 ⁄2 (64) ⁄2 (13)
12 (3.658) A A B D D E F G F 3 (76) ⁄8 (10)
14 (4.267) A A B D E F F G G 3 (76) ⁄2 (13)
16 (4.877) A A C E E G G H H 3 (76) ⁄8 (16)
18 (5.486) A A C E F G G H J 3 (76) ⁄4 (19)
20 (6.096) A A D E F G H J K 3 (76) 1 (25)
24 (7.315) A B D F G H J K
30 (9.144) A B E G H H K K
36 (10.973) A B E H J K K
40 (12.192) A B E H J K
A
This table is based on handling considerations only. Significant superimposed loads, such as from wind or seismic conditions, should be considered independently.
B
Reinforcement configurations other than a flange may be used if equal or greater stiffness is provided.
C
L = maximum distance from flange to the tank bottom or to the uppermost shell stiffener when used.
D
Flange thickness shall be at least equal to local vessel thickness.
D3299 − 18
6.3.4.2 Joints between tank-wall sections shall be overwound to a thickness as calculated in 6.1.3.2, or they may be overlaid
by a contact-molded laminate. When contact-molded laminate joints are used to join hoop segments of the straight shell, or to join
the bottom or top head to the shell, the thickness of the structural joint overlay shall be determined by the following equation, but
shall not be less than ⁄16 in. (4.8 mm):
PD 0.036γHD 0.2489γHD
t 5 5 or (10)
S D
2S 2S 2S
h h h
where:
t = wall thickness, in. (mm),
S = allowable hoop tensile strength (not to exceed ⁄10 of the ultimate hoop strength), psi (kPa),
h
P = pressure, psi (kPa),
H = fluid head, in. (mm),
γ = specific gravity of fluid, and
D = inside diameter of tank, in. (mm).
6.3.4.3 The minimum width of the structural joint overlay for bottom-supported tanks is shown in Table 3.
6.3.4.4 The corrosion-resistant barrier component of the joint shall be formed in the same manner as the inner surface and the
interior layer (7.1.1 and 7.1.2) and the minimum overlay width shall be 4 in. (100 mm). This internal overlay shall not be
considered a structural element in determining joint thickness.
6.3.4.5 The thickness of a joint near the bottom tangent line shall not be considered to contribute to the knuckle reinforcement
of 6.3.2.3, but shall be additive thereto.
6.3.5 Fittings:
6.3.5.1 The more common method of fabricating nozzles is by contact molding both the nozzle neck and flange to the
dimensions shown in Specification D5421 and Table 4. The corrosion-resistant barrier of the nozzle shall be at least equivalent to
the inner surface and interior layer (7.1.1 and 7.1.2) and shall be fabricated from the same resin as the tank head or shell to which
it is attached.
6.3.5.2 Acceptable alternative methods to be agreed upon between fabricator and purchaser are the use of contact-molded pipe,
filament-wound pipe, in accordance with Specification D2996, or centrifugally cast pipe, in accordance with Specification D2997,
joined to a suitable contact-molded (Specification D5421), or filament-wound flange (Specification D4024). The corrosion-
resistant barrier of the contact-molded portions of such nozzles shall be equivalent to the inner surface and interior layer (7.1.1 and
7.1.2) and shall be fabricated from the same resin as the tank head or shell to which they are attached.
TABLE 3 Minimum Widths of Joint Overlay for Circumferential Joints
A
H × D = 60 100 140 180 220 260 300 340 380 420 460 500
minimum
width of
B
outside
in. 4 4 5 6 7 8 9 10 11 12 13 14
(mm) (102) (102) (127) (152) (178) (203) (229) (254) (279) (305) (330) (356)
A
where: H = distance from the top of the liquid level to the joint, ft (m) and
D = inside diameter of the tank, ft (m).
B
Axial joint overlay widths shall be twice the width shown in table.
D3299 − 18
TABLE 4 Dimensions for Contact-Molded Flanged Nozzles (25 psi Rating)
Nozzle Inside Minimum Wall Minimum Flange Minimum Hub Minimum Hub Length
Diameter (D), in. (mm) Thickness (t ), Thickness (t ), in. Thickness (t ), (h), in. (mm)
n f h
in. (mm) (mm) in. (mm)
3 1 1
1 (25) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
1 3 1 1
1 ⁄2 (38) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 1 1
2 (51) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 1 1
3 (76) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 1 1
4 (102) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 1 1
6 (152) ⁄16 (5) ⁄2 (13) ⁄4 (6) 2 (51)
3 9 5 1
8 (203) ⁄16 (5) ⁄16 (14) ⁄16 (8) 2 ⁄2 (57)
3 11 3 3
10 (254) ⁄16 (5) ⁄16 (17) ⁄8 (10) 2 ⁄4 (70)
3 3 3
12 (305) ⁄16 (5) ⁄4 (19) ⁄8 (10) 3 (76)
1 13 7 1
14 (356) ⁄4 (6) ⁄16 (21) ⁄16 (11) 3 ⁄4 (83)
1 7 7 1
16 (406) ⁄4 (6) ⁄8 (22) ⁄16 (11) 3 ⁄2 (89)
1 15 1 3
18 (457) ⁄4 (6) ⁄16 (24) ⁄2 (13) 3 ⁄4 (95)
1 1
20 (508) ⁄4 (6) 1 (25) ⁄2 (13) 4 (102)
1 1 9 1
24 (610) ⁄4 (6) 1 ⁄8 (29) ⁄16 (14) 4 ⁄2 (114)
6.3.5.3 Nozzles 4 in. (100 mm) and smaller shall be supported by a suitable gusseting technique, using plate gussets or conical
gussets, as shown in Fig. 4 and Fig. 5. Plate gussets, where needed, shall be evenly spaced around the nozzle and are to be added
FIG. 4 Plate-Type Gussets
D3299 − 18
NOTE 1—This design does not require lay-up of nozzle neck to exterior of tank wall. Nozzle may be penetrating type or flush type as illustrated.
FIG. 5 Conical Type Gussets
after complete assembly by the nozzle on the shell. Larger nozzles, subject to superimposed mechanical forces, require special
consideration.
6.3.5.4 Manways installed in top heads may be of the flanged or nonflanged design, as agreed upon between the fabricator and
purchaser.
6.3.5.5 Side-shell manways shall be installed in accordance with 7.3.2, 7.3.3, and Fig. 6.
6.3.5.6 Typical manway dimensions are shown in Table 5.
NOTE 13—Tanks over 6 ft (1.8 m) straight-shell height may need both top- and side-shell opening manways for safety and maintenance considerations.
6.4 Vents:
NOTE 1—This installation method is used only when the nozzle is being installed with an integral conical gusset which would prevent application of
an exterior laminate.
FIG. 6 Nozzle Installation and Cutout Reinforcement Location Alternative
D3299 − 18
TABLE 5 Typical Dimensions of Manways
NOTE 1—Bolt size equals bolt hole diameter minus ⁄8 in. (3 mm).
NOTE 2—Gaskets shall be ⁄8 in. thick full-face elastomeric material having a hardness of Shore A80 ± 5.
Minimum Minimum Diameter of Minimum Thickness of Minimum Manway Diameter of Bolt Number of Bolt Hole Diameter, in.
ABC
Size, in. Flange and Cover, in. Flange and Cover, in. Wall Thickness, in. Circle, in. (mm) Bolts (mm)
(mm) (mm) (mm) (mm)
Pressurized
...