ASTM C582-23

Standard Specification for Contact-Molded Reinforced Thermosetting Plastic (RTP) Laminates for Corrosion-Resistant Equipment

ABSTRACT
This specification covers composition, thickness, fabricating procedures, and physical property requirements for glass fiber reinforced thermoset polyester, vinyl ester, or other qualified thermosetting resin laminates comprising the materials of construction for RTP corrosion-resistant tanks, piping, and equipment. This specification is limited to fabrication by contact molding. Laminates shall be classified according to type, class, and grade: Types I and II; Classes P and V. Tensile strength and tangent modulus of elasticity, flexural strength, glass content, thickness, hardness, chemical resistance, and surface flame-spread classification tests shall be performed to conform to the specified requirements.
SCOPE
1.1 This specification covers composition, thickness, fabricating procedures, and physical property requirements for glass fiber reinforced thermoset polyester, vinyl ester, or other qualified thermosetting resin laminates comprising the materials of construction for RTP corrosion-resistant tanks, piping, and equipment. This specification is limited to fabrication by contact molding.  
Note 1: The laminates covered by this specification are manufactured during fabrication of contact-molded RTP tanks, piping, and other equipment.
Note 2: There is no known ISO equivalent to this standard.  
1.2 The values stated in inch-pound units are to be regarded as standard. The SI values given in parentheses are conversions from inch-pound units and are for information only.  
1.3 The following safety hazards caveat pertains only to the test method portion, Section 8, 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.  
1.4 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-Mar-2023
• ICS: 83.140.20 - Laminated sheets
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.23 - Reinforced Thermosetting Resin Piping Systems and Chemical Equipment

Relations

• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM E84-23d - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Dec-2023
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM E84-23c - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Sep-2023
• 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 E84-19b - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Jul-2019
• Refers: ASTM E84-19a - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 15-Apr-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM E84-19 - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Mar-2019
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-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 E84-18b - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Oct-2018

Overview

ASTM C582-23, published by ASTM International, provides a standard specification for contact-molded reinforced thermosetting plastic (RTP) laminates used in the construction of corrosion-resistant equipment. This standard addresses the composition, thickness, fabrication procedures, and performance requirements for glass fiber-reinforced laminates using polyester, vinyl ester, or other qualified thermosetting resins. The specification is specifically limited to products manufactured by contact molding methods and covers tanks, piping, and related equipment designed to withstand corrosive environments.

Key Topics

• Material Composition: The specification sets out requirements for the resin matrix (such as polyester and vinyl ester resins), glass fiber reinforcements, and any additional agents or fillers. Compatibility between resin and fibers is essential.
• Laminate Types and Classification: Laminates are classified by type (e.g., Type I and II, differing in reinforcement structure), class (resin type: P for polyester, V for vinyl ester, including fire-retardant variants), grade (minimum physical property levels), and thickness.
• Fabrication Procedures: The standard defines the contact molding process, where glass fiber reinforcement is hand or machine-applied, saturated with resin, and consolidated by rolling. Lamination sequences and ply overlaps are controlled to ensure quality.
• Mechanical and Physical Property Requirements: Minimum standards are set for tensile strength, flexural strength, modulus of elasticity, glass content, thickness, hardness, and chemical resistance.
• Quality and Appearance: Specifications are given for surface finish and visual attributes including the absence of cracks, excessive porosity, and other defects, ensuring suitability for corrosion-resistant service.

Applications

ASTM C582-23 is widely applicable in industries where chemical resistance and material durability are critical. Key applications include:

• Corrosion-Resistant Tanks: Used for storing aggressive chemicals in various industrial processes.
• Process Piping: RTP pipes built to this standard perform reliably in chemical plants, wastewater treatment facilities, and other corrosive environments.
• Special Equipment: Vessels, ducts, hoods, and other components exposed to harsh chemicals are manufactured following this specification.
• OEM and Custom Fabrication: Both standard and custom-designed corrosion-resistant equipment can be certified for compliance with ASTM C582-23.

The specification assures buyers, fabricators, and engineers of consistent quality, reliable performance, and safe operation in challenging environments. Additionally, compliance facilitates procurement, inspection, and long-term maintenance planning for chemical and process industries.

Related Standards

• ASTM C581 - Practice for Determining Chemical Resistance of Thermosetting Resins in Glass-Fiber-Reinforced Structures Used in Liquid Service.
• ASTM D638 - Test Method for Tensile Properties of Plastics.
• ASTM D695 - Test Method for Compressive Properties of Rigid Plastics.
• ASTM D790 - Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials.
• ASTM D883 - Terminology Relating to Plastics.
• ASTM D2584 - Test Method for Ignition Loss of Cured Reinforced Resins.
• ASTM E84 - Test Method for Surface Burning Characteristics of Building Materials.

These referenced standards provide test methods and terminology to ensure that RTP laminates meet the performance and safety benchmarks established by ASTM C582-23. There is currently no ISO equivalent for this standard.

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Keywords: ASTM C582-23, contact-molded laminate, corrosion-resistant equipment, glass fiber reinforced plastic, reinforced thermosetting plastic (RTP), chemical-resistant tank fabrication, process piping, vinyl ester resin, polyester resin, industrial laminates, ASTM standard.

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: C582 − 23
Standard Specification for
Contact-Molded Reinforced Thermosetting Plastic (RTP)
Laminates for Corrosion-Resistant Equipment
This standard is issued under the fixed designation C582; 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 C581 Practice for Determining Chemical Resistance of
Thermosetting Resins Used in Glass-Fiber-Reinforced
1.1 This specification covers composition, thickness, fabri-
Structures Intended for Liquid Service
cating procedures, and physical property requirements for glass
D638 Test Method for Tensile Properties of Plastics
fiber reinforced thermoset polyester, vinyl ester, or other
D695 Test Method for Compressive Properties of Rigid
qualified thermosetting resin laminates comprising the materi-
Plastics
als of construction for RTP corrosion-resistant tanks, piping,
D790 Test Methods for Flexural Properties of Unreinforced
and equipment. This specification is limited to fabrication by
and Reinforced Plastics and Electrical Insulating Materi-
contact molding.
als
NOTE 1—The laminates covered by this specification are manufactured
D883 Terminology Relating to Plastics
during fabrication of contact-molded RTP tanks, piping, and other
D2583 Test Method for Indentation Hardness of Rigid Plas-
equipment.
tics by Means of a Barcol Impressor (Withdrawn 2022)
NOTE 2—There is no known ISO equivalent to this standard.
D2584 Test Method for Ignition Loss of Cured Reinforced
1.2 The values stated in inch-pound units are to be regarded
Resins
as standard. The SI values given in parentheses are conversions
D3681 Test Method for Chemical Resistance of “Fiberglass”
from inch-pound units and are for information only.
(Glass–Fiber–Reinforced Thermosetting-Resin) Pipe in a
1.3 The following safety hazards caveat pertains only to the
Deflected Condition
test method portion, Section 8, of this specification: This
E84 Test Method for Surface Burning Characteristics of
standard does not purport to address all of the safety concerns,
Building Materials
if any, associated with its use. It is the responsibility of the user
of this standard to establish appropriate safety, health, and
3. Definitions
environmental practices and determine the applicability of
3.1 Definitions used in this specification are in accordance
regulatory limitations prior to use.
with Terminology D883 unless otherwise indicated. The ab-
1.4 This international standard was developed in accor-
breviation for reinforced thermoset plastic is RTP.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the 3.2 polyester—resins produced by the polycondensation of
Development of International Standards, Guides and Recom- dihydroxyderivatives and dibasic organic acids or anhydrides,
mendations issued by the World Trade Organization Technical wherein at least one component contributes ethylenic unsatu-
Barriers to Trade (TBT) Committee. ration yielding resins that can be compounded with styryl
monomers and reacted to give highly crosslinked thermoset
2. Referenced Documents
copolymers.
2.1 ASTM Standards:
3.3 vinyl ester—resins characterized by reactive unsatura-
tion located predominately in terminal positions that can be
compounded with styryl monomers and reacted to give highly
This specification is under the jurisdiction of ASTM Committee D20 on
crosslinked thermoset copolymers.
Plastics and is the direct responsibility of Subcommittee D20.23 on Reinforced
Thermosetting Resin Piping Systems and Chemical Equipment.
NOTE 3—These resins are handled in the same way as polyesters in
Current edition approved April 1, 2023. Published April 2023. Originally
fabrication of RTP components.
approved in 1965. Last previous edition approved in 2016 as C582 – 09(2016). DOI:
10.1520/C0582-23.
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 last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C582 − 23
used as elements of a fire risk assessment that takes into account all the
3.4 contact molding—a method of fabrication wherein the
factors that are pertinent to an assessment of the fire hazard or a particular
glass-fiber reinforcement is applied to the mold, in the form of
end use.
chopped strand mat or woven roving, by hand or from a reel,
or in the form of chopped strands of continuous-filament glass 4.1.3 Grade—In Arabic numerals, shall designate the mini-
from a chopper-spray gun. The resin matrix is applied by mum physical property levels of a laminate at 73 6 4°F (23 6
various methods, including brush, roller, or spray gun. Con- 2°C).
solidation of the composite laminate is by rolling.
NOTE 6—The five Arabic grade numbers designate minimum physical
property levels of a laminate obtained from tests of representative
4. Classification
production process samples. They are not arbitrarily selected values.
4.1 Laminates shall be classified according to type, class,
4.1.4 Thickness—Nominal, shall be designated by Arabic
and grade.
number to nearest 0.01 in. or 0.1 mm. (See Table 1 and Table
4.1.1 Type—In Roman numerals, shall designate the rein-
2 for standard thicknesses.)
forcement structure comprised of specific plies of glass fiber in
specific sequences.
NOTE 7—Table 1 and Table 2 are for reference purposes and do not
4.1.1.1 Type I—A standard all-mat or chopped-roving preclude other laminate-type constructions, such as nonwoven biaxial or
unidirectional fabric, which may be agreed upon between the buyer and
construction, or both, as shown in Table 1.
the seller, or may be added to this specification if they have been fully
4.1.1.2 Type II—A standard mat or chopped-roving and
identified and characterized, as shown in Appendix X2.
woven-roving construction, or combination thereof, as shown
4.1.5 Classification Requirements for Different Laminates—
in Table 2.
Laminate designation from Table 3 shall consist of the abbre-
4.1.1.3 Other types, such as standard mat or chopped roving
viation RTP followed by (1) type in Roman numerals; (2) class
with alternating layers of nonwoven biaxial or unidirectional
in capital letters followed by FS( ) if required; (3) grade
reinforcement in the structured plies. may be qualified in
consisting of five Arabic numbers to designate minimum levels
accordance with Appendix X2.
of physical properties and (4) thickness designated by Arabic
4.1.2 Class—In capital letters, shall designate the generic
number in decimal inches (or ALL, if properties apply to all
resin: “P” for polyester and “V” for vinyl ester. The letters
thicknesses).
“FS” followed by parenthesis, “FS( ),” shall designate fire
retardancy, if specified, with maximum flame spread in the 4.1.5.1 Examples:
parentheses in accordance with Test Method E84.
(1) RTP I 1 ALL, designates Type I polyester laminate,
non-fire-retardant Grade 13211, having the following mini-
NOTE 4—Fire retardancy by Test Method E84 is determined for a
mum physical property levels (see Table 3):
nominal 0.13-in. (3-mm) thick, flat laminates with all-mat glass content of
25 to 30 %. Tensile strength, ultimate—9,000 psi (62.1 MPa).
NOTE 5—Maximum flame spread designation by Test Method E84
Tensile modulus—1,050,000 psi (7.24 GPa).
relates to measurement and description of the properties of materials,
Flexural strength, ultimate—18,000 psi (124 MPa).
products, or systems in response to heat and flame under controlled
Flexural modulus—700,000 psi (4.83 GPa).
laboratory conditions and should not be considered or used for the
Glass content—25 %.
description or appraisal of the fire hazard of materials, products, or
systems under actual fire conditions. However, results of this test may be Thickness—“ALL” thicknesses.
A
TABLE 1 Standard Laminate Composition Type I
E
Calculated Corrosion Structural Plies Drafting
BC D
Number and Sequence of Plies
Thickness Barrier Symbols
in. (mm) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
0.18 (4.6) V M M M M V, 4M
0.23 (5.8) V M M M M M V, 5M
0.27 (6.9) V M M M M M M V, 6M
0.31 (7.9) V M M M M M M M V, 7M
0.35 (8.9) V M M M M M M M M V, 8M
0.40 (10.2) V M M M M M M M M M V, 9M
0.44 (11.2) V M M M M M M M M M M V, 10M
0.48 (12.2) V M M M M M M M M M M M V, 11M
0.53 (13.5) V M M M M M M M M M M M M V, 12M
0.57 (14.5) V M M M M M M M M M M M M M V, 13M
0.61 (15.5) V M M M M M M M M M M M M M M V, 14M
0.66 (16.8) V M M M M M M M M M M M M M M M V, 15M
0.70 (17.8) V M M M M M M M M M M M M M M M M V, 16M
0.74 (18.8) V M M M M M M M M M M M M M M M M M V, 17M
A
Glass content, weight, % = 25 to 30, all thickness.
B
Calculated thickness for design purposes is determined as follows:
V = Surfacing mat − 0.010 in./ply (0.25 mm/ply) when saturated with resin.
2 2
M = 1 ⁄2 oz/ft (450 g/m ) mat − 0.043 in./ply (1.1 mm/ply) nominal values when saturated with resin.
C
The thickness shall be not less than 90 % of the calculated thickness shown.
D
Corrosion barrier (Plies 1, 2, and 3) shall gel before structural plies are added.
E
Structural lay-up may be interrupted at intervals long enough to exotherm if required by the laminate manufacturing procedure and 6.3.1.
C582 − 23
TABLE 2 Standard Laminate Composition Type II
D
Glass
Calculated Corrosion
Structural Plies
AB C
Content Drafting
Number and Sequence of Plies
Thickness Barrier
(weight, Symbols
in. (mm) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
%)
0.22 (5.6) 28 to 33 V M M M R M V, 2M, MRM
0.29 (7.4) 30 to 35 V M M M R M R M V, 2M, 2(MR)M
0.37 (9.4) 30 to 35 V M M M R M R M R M V, 2M, 3(MR)M
0.41 (10.4) 30 to 35 V M M M R M R M R M M V, 2M, 3(MR)M,
M
0.49 (12.5) 34 to 38 V M M M R M R M R M M R M V, 2M, 3(MR)M,
MRM
0.57 (14.5) 34 to 38 V M M M R M R M R M M R M R M V, 2M, 3(MR)M,
2(MR)M
0.64 (16.3) 37 to 41 V M M M R M R M R M M R M R M R M V, 2M, 3(MR)M,
3(MR)M
0.69 (17.5) 37 to 41 V M M M R M R M R M M R M R M R M M V, 2M, 3(MR)M,
3(MR)M,M
0.76 (19.3) 37 to 41 V M M M R M R M R M M R M R M R M M R M V, 2M, 3(MR)M,
3(MR)M,
MRM
A
Calculated thickness for design purposes is determined as follows:
V = Surfacing mat − 0.010 in./ply (0.25 mm/ply) when saturated with resin.
2 2
M = 1 ⁄2 oz ⁄ft (450 g/m ) mat = 0.043 in./ply (1.1 mm/ply) when saturated with resin.
2 2
R = 24 ⁄2 oz/yd (800 g/m ) 5 × 4 woven roving = 0.033 in./ply (0.84 mm/ply) nominal values when saturated with resin.
B
The thickness shall be not less than 90 % of the calculated thickness shown.
C
Corrosion barrier (Plies 1, 2, and 3) shall gel before structural plies are added.
D
Structural lay-up may be interrupted long enough to exotherm following an “M” ply, if required by the laminate manufacturing procedure. Location of exotherm plies may
be shifted within the laminate body. No plies may be omitted. Refer to 6.3.1.
A
TABLE 3 Classification System for Hand Lay-up Laminates Using Minimum Property Values
Classification Order
RTP followed by:
(1) Type I II III IV V
(2) Class P V . . . . . . . . . followed by FS ( ), if
Polyester Vinylester specified with flame
spread in
parentheses in
accordance with Test
Method E84
Physical and Mechanical Properties
(3) Grade 1 2 3 4 5 6 7 8 9 0
Tensile strength, Ultimate
1st
psi × 10 9 11 13 15 17.5 20 . . . . . . . . . . . .
Digit:
(MPa) (62.1) (75.8) (89.6) (103) (121) (138) . . . . . . . . . . . .
Tensile modulus, tangent
2nd
psi × 10 0.85 0.95 1.05 1.15 1.3 1.5 1.75 2.0 . . . . . .
Digit:
(GPa) (5.86) (6.55) (7.24) (7.93) (8.96) (10.3) (12.1) (13.8) . . . . . .
Flexural strength, ultimate
3rd
psi × 10 16 18 20 22 24 . . . . . . . . . . . . . . .
Digit:
(MPa) (110) (124) (138) (152) (166) . . . . . . . . . . . . . . .
Flexural modulus
4th
psi × 10 0.7 0.85 1.0 1.15 1.3 1.5 . . . . . . . . . . . .
Digit:
(GPa) (4.83) (5.86) (6.90) (7.93) (8.96) (10.3) . . . . . . . . . . . .
5th Glass content, by weight, % 25 28 30 34 37 40 44 . . . . . . . . .
Digit:
A
Table will be completed as new resins and higher strength laminates become available.
(2) RTP II P FS(25) 55433.29, designates Type II, poly- Flexural modulus—1,000,000 psi (6.90 GPa).
ester fire-retardant resin laminate with a maximum flame Glass content—30 %.
spread of 25, Grade 55433 having the following minimum
Thickness—0.29 in. (7.4 mm).
physical property levels (see Table 3):
Tensile strength, ultimate—17,500 psi (121 MPa).
5. Materials
Tensile modulus—1,300,000 psi (8.96 GPa).
5.1 Resin Matrix System:
Flexural strength, ultimate—22,000 psi (152 MPa).
C582 − 23
5.1.1 The resin shall be determined to be acceptable for the grade of “E” or “ECR” type glass fiber with a sizing that is
service either by test, see 8.6, or by verified case history. compatible with the resin.
5.1.2 Catalyst/Promoter System, shall be as recommended
5.3 Laminates:
or approved by the resin producer.
5.3.1 Laminate construction shall be in accordance with the
5.1.3 Diluents, such as added styrene, fillers, dyes,
tabulated lay-up sequence for the specified type.
pigments, or flame retardants shall be used only when agreed
5.3.2 Type I, laminate structure is detailed in Table 1.
upon between the fabricator and the buyer. When such items
5.3.3 Type II, laminate structure is detailed in Table 2.
are required, limits for each shall be agreed upon between the
fabricator and the buyer. A thixotropic agent may be added to
6. Laminate Fabrication
the resin for viscosity control.
6.1 Apply the catalyzed resin to a mold or mandrel properly
prepared with a parting agent or film suitable for the lay-up
NOTE 8—The addition of fillers, dyes, pigments, flame retardants, and
thixotropic agents may interfere with visual inspection of laminate quality.
resin. Next apply the specified surface mat, rolling so as to
NOTE 9—Chemical resistance can be significantly affected by the
draw the resin through the mat for thorough wet-out and
catalyst/promoter system, diluents, dyes, fillers, flame retardants, or
deaeration.
thixotropic agent used in the resin.
6.2 Apply resin and two plies of 1 ⁄2-oz (450-g) mat. As an
5.1.4 Resin Paste
...

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: C582 − 09 (Reapproved 2016) C582 − 23
Standard Specification for
Contact-Molded Reinforced Thermosetting Plastic (RTP)
Laminates for Corrosion-Resistant Equipment
This standard is issued under the fixed designation C582; 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 composition, thickness, fabricating procedures, and physical property requirements for glass fiber
reinforced thermoset polyester, vinyl ester, or other qualified thermosetting resin laminates comprising the materials of construction
for RTP corrosion-resistant tanks, piping, and equipment. This specification is limited to fabrication by contact molding.
NOTE 1—The laminates covered by this specification are manufactured during fabrication of contact-molded RTP tanks, piping, and other equipment.
NOTE 2—There is no known ISO equivalent to this standard.
1.2 The values stated in inch-pound units are to be regarded as standard. The SI values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.conversions from inch-pound units
and are for information only.
1.3 The following safety hazards caveat pertains only to the test method portion, Section 8, 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.
1.4 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
D638 Test Method for Tensile Properties of Plastics
D695 Test Method for Compressive Properties of Rigid Plastics
D790 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials
D883 Terminology Relating to Plastics
This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.23 on Reinforced Plastic
Thermosetting Resin Piping Systems and Chemical Equipment.
Current edition approved Nov. 1, 2016April 1, 2023. Published November 2016April 2023. Originally approved in 1965. Last previous edition approved in 20092016 as
C582 – 09.C582 – 09(2016). DOI: 10.1520/C0582-09R16.10.1520/C0582-23.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C582 − 23
D2583 Test Method for Indentation Hardness of Rigid Plastics by Means of a Barcol Impressor (Withdrawn 2022)
D2584 Test Method for Ignition Loss of Cured Reinforced Resins
D3681 Test Method for Chemical Resistance of “Fiberglass” (Glass–Fiber–Reinforced Thermosetting-Resin) Pipe in a Deflected
Condition
E84 Test Method for Surface Burning Characteristics of Building Materials
3. Definitions
3.1 Definitions used in this specification are in accordance with Terminology D883 unless otherwise indicated. The abbreviation
for reinforced thermoset plastic is RTP.
3.2 polyester—resins produced by the polycondensation of dihydroxyderivatives and dibasic organic acids or anhydrides, wherein
at least one component contributes ethylenic unsaturation yielding resins that can be compounded with styryl monomers and
reacted to give highly crosslinked thermoset copolymers.
3.3 vinyl ester—resins characterized by reactive unsaturation located predominately in terminal positions that can be compounded
with styryl monomers and reacted to give highly crosslinked thermoset copolymers.
NOTE 3—These resins are handled in the same way as polyesters in fabrication of RTP components.
3.4 contact molding—a method of fabrication wherein the glass-fiber reinforcement is applied to the mold, in the form of chopped
strand mat or woven roving, by hand or from a reel, or in the form of chopped strands of continuous-filament glass from a
chopper-spray gun. The resin matrix is applied by various methods, including brush, roller, or spray gun. Consolidation of the
composite laminate is by rolling.
4. Classification
4.1 Laminates shall be classified according to type, class, and grade.
4.1.1 Type—In Roman numerals, shall designate the reinforcement structure comprised of specific plies of glass fiber in specific
sequences.
A
TABLE 1 Standard Laminate Composition Type I
E
Calculated Corrosion Structural Plies Drafting
BC D
Number and Sequence of Plies
Thickness Barrier Symbols
in. (mm) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
0.18 (4.6) V M M M M V, 4M
0.23 (5.8) V M M M M M V, 5M
0.27 (6.9) V M M M M M M V, 6M
0.31 (7.9) V M M M M M M M V, 7M
0.35 (8.9) V M M M M M M M M V, 8M
0.40 (10.2) V M M M M M M M M M V, 9M
0.44 (11.2) V M M M M M M M M M M V, 10M
0.48 (12.2) V M M M M M M M M M M M V, 11M
0.53 (13.5) V M M M M M M M M M M M M V, 12M
0.57 (14.5) V M M M M M M M M M M M M M V, 13M
0.61 (15.5) V M M M M M M M M M M M M M M V, 14M
0.66 (16.8) V M M M M M M M M M M M M M M M V, 15M
0.70 (17.8) V M M M M M M M M M M M M M M M M V, 16M
0.74 (18.8) V M M M M M M M M M M M M M M M M M V, 17M
A
Glass content, weight, % = 25 to 30, all thickness.
B
Calculated thickness for design purposes is determined as follows:
V = Surfacing mat − 0.010 in./ply (0.25 mm/ply) when saturated with resin.
2 2
M = 1 ⁄2 oz/ft (459(450 g/m ) mat − 0.043 in./ply (1.1 mm/ply) nominal values when saturated with resin.
C
The thickness shall be not less than 90 % of the calculated thickness shown.
D
Corrosion barrier (Plies 1, 2, and 3) shall gel before structural plies are added.
E
Structural lay-up may be interrupted at intervals long enough to exotherm if required by the laminate manufacturing procedure and 6.3.1.
The last approved version of this historical standard is referenced on www.astm.org.
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4.1.1.1 Type I—A standard all-mat or chopped-roving construction, or both, as shown in Table 1.
4.1.1.2 Type II—A standard mat or chopped-roving and woven-roving construction, or combination thereof, as shown in Table 2.
4.1.1.3 Other types, such as standard mat or chopped roving with alternating layers of nonwoven biaxial or unidirectional
reinforcement in the structured plies. may be qualified in accordance with Appendix X2.
4.1.2 Class—In capital letters, shall designate the generic resin: “P” for polyester and “V” for vinyl ester. The letters “FS” followed
by parenthesis, “FS( ),” shall designate fire retardancy, if specified, with maximum flame spread in the parentheses in accordance
with Test Method E84.
NOTE 4—Fire retardancy by Test Method E84 is determined for 0.125-in. (3.175-mm) a nominal 0.13-in. (3-mm) thick, flat laminates with all-mat glass
content of 25 to 30 %.
NOTE 5—Maximum flame spread designation by Test Method E84 relates to measurement and description of the properties of materials, products, or
systems in response to heat and flame under controlled laboratory conditions and should not be considered or used for the description or appraisal of the
fire hazard of materials, products, or systems under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment
that takes into account all the factors that are pertinent to an assessment of the fire hazard or a particular end use.
4.1.3 Grade—In Arabic numerals, shall designate the minimum physical property levels of a laminate at 73.4 6 3.6°F73 6 4°F
(23 6 2°C).
NOTE 6—The five Arabic grade numbers designate minimum physical property levels of a laminate obtained from tests of representative production
process samples. They are not arbitrarily selected values.
4.1.4 Thickness—Nominal, shall be designated by Arabic number in decimal hundredths of an inch. to nearest 0.01 in. or 0.1 mm.
(See Table 1 and Table 2 for standard thicknesses.)
NOTE 7—Table 1 and Table 2 are for reference purposes and do not preclude other laminate-type constructions, such as nonwoven biaxial or unidirectional
fabric, which may be agreed upon between the buyer and the seller, or may be added to this specification if they have been fully identified and
characterized, as shown in Appendix X2.
TABLE 2 Standard Laminate Composition Type II
Glass D
Calculated Corrosion Structural Plies
AB C
Content Number and Sequence of Plies Drafting
Thickness Barrier
(weight, Symbols
in. (mm) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
%)
0.22 (5.6) 28 to 33 V M M M R M V, 2M, MRM
0.29 (7.4) 30 to 35 V M M M R M R M V, 2M, 2(MR)M
0.37 (9.4) 30 to 35 V M M M R M R M R M V, 2M, 3(MR)M
0.41 (10.4) 30 to 35 V M M M R M R M R M M V, 2M, 3(MR)M,
M
0.49 (12.5) 34 to 38 V M M M R M R M R M M R M V, 2M, 3(MR)M,
MRM
0.57 (14.5) 34 to 38 V M M M R M R M R M M R M R M V, 2M, 3(MR)M,
2(MR)M
0.64 (16.3) 37 to 41 V M M M R M R M R M M R M R M R M V, 2M, 3(MR)M,
3(MR)M
0.69 (17.5) 37 to 41 V M M M R M R M R M M R M R M R M M V, 2M, 3(MR)M,
3(MR)M,M
0.76 (19.3) 37 to 41 V M M M R M R M R M M R M R M R M M R M V, 2M, 3(MR)M,
3(MR)M,
MRM
A
Calculated thickness for design purposes is determined as follows:
V = Surfacing mat − 0.010 in./ply (0.25 mm/ply) when saturated with resin.
1 2 2
M = 1 ⁄2 oz ⁄ft (459(450 g/m ) mat = 0.043 in./ply (1.1 mm/ply) when saturated with resin.
2 2
R = 24 ⁄2 oz/yd (832(800 g/m ) 5 × 4 woven roving = 0.033 in./ply (0.84 mm/ply) nominal values when saturated with resin.
B
The thickness shall be not less than 90 % of the calculated thickness shown.
C
Corrosion barrier (Plies 1, 2, and 3) shall gel before structural plies are added.
D
Structural lay-up may be interrupted long enough to exotherm following an “M” ply, if required by the laminate manufacturing procedure. Location of exotherm plies may
be shifted within the laminate body. No plies may be omitted. Refer to 6.3.1.
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4.1.5 Classification Requirements for Different Laminates—Laminate designation from Table 3 shall consist of the abbreviation
RTP followed by (1) type in Roman numerals; (2) class in capital letters followed by FS( ) if required; (3) grade consisting of
five Arabic numbers to designate minimum levels of physical properties and (4) thickness designated by Arabic number in decimal
inches (or ALL, if properties apply to all thicknesses).
4.1.5.1 Examples:
(1) RTP I 1 ALL, designates Type I polyester laminate, non-fire-retardant Grade 13211, having the following minimum
physical property levels (see Table 3):
Tensile strength, ultimate—9000 psi (62ultimate—9,000 psi (62.1 MPa).
Tensile modulus—1 050 000 psi (7242 MPa).modulus—1,050,000 psi (7.24 GPa).
Flexural strength, ultimate—18 000ultimate—18,000 psi (124 MPa).
Flexural modulus—700 000 psi (4828 MPa).modulus—700,000 psi (4.83 GPa).
Glass content—25 %.
Thickness—“ALL” thicknesses.
A
TABLE 3 Classification System for Hand Lay-up Laminates Using Minimum Property Values
Classification Order
RTP followed by:
(1) Type I II III IV V
(2) Class P V . . . . . . . . . followed by FS ( ), if
Polyester Vinylester specified with
flame
spread in
parentheses in
accordance with
Test
Method E84
(2) Class P V . . . . . . . . . followed by FS ( ), if
Polyester Vinylester specified with flame
spread in parenthe-
ses in
accordance with Test
Method E84
Physical and Mechanical Properties
(3) Grade 1 2 3 4 5 6 7 8 9 0
Tensile strength, Ultimate
1st 1st Digit: Tensile 9 11 13 15 17.5 20 . . . . . . . . . . . .
Digit: strength,
psi × 10 9 11 13 15 17.5 20 . . . . . . . . . . . .
ultimate psi × 10
(MPa) (62) (76) (90) (104) (121) (138) . . . . . . . . . . . .
(MPa) (62.1) (75.8) (89.6) (103) (121) (138) . . . . . . . . . . . .
Tensile modulus, tangent
2nd 2nd Digit: Tensile 0.85 0.95 1.05 1.15 1.3 1.5 1.75 2.0 . . . . . .
Digit: modulus,
psi × 10 0.85 0.95 1.05 1.15 1.3 1.5 1.75 2.0 . . . . . .
tangent psi × 10
(MPa) (5 863) (6 552) (7 242) (7 932) (8 966) (10 346) (12 070) (13 794) . . . . . .
(GPa) (5.86) (6.55) (7.24) (7.93) (8.96) (10.3) (12.1) (13.8) . . . . . .
Flexural strength, ultimate
3rd 3rd Digit: Flexural 16 18 20 22 24 . . . . . . . . . . . . . . .
Digit: strength,
psi × 10 16 18 20 22 24 . . . . . . . . . . . . . . .
ultimate psi × 10
(MPa) (110) (124) (138) (152) (166) . . . . . . . . . . . . . . .
(MPa) (110) (124) (138) (152) (166) . . . . . . . . . . . . . . .
Flexural modulus
4th 4th Digit: Flexural 0.7 0.85 1.0 1.15 1.3 1.5 . . . . . . . . . . . .
Digit: modulus,
psi × 10 0.7 0.85 1.0 1.15 1.3 1.5 . . . . . . . . . . . .
psi × 10
(MPa) (4 828) (5 863) (6 897) (7 932) (8 966) (10 346) . . . . . . . . . . . .
(GPa) (4.83) (5.86) (6.90) (7.93) (8.96) (10.3) . . . . . . . . . . . .
5th Glass content, by weight, % 25 28 30 34 37 40 44 . . . . . . . . .
Digit:
weight, %
A
TableTable will be completed as new resins and higher strength laminates become available.
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(2) RTP II P FS(25) 55433.30,55433.29, designates Type II, polyester fire-retardant resin laminate with a maximum flame
spread of 25, Grade 55433 having the following minimum physical property levels (see Table 3):
Tensile strength, ultimate—17 500ultimate—17,500 psi (121 MPa).
Tensile modulus—1 300 000 psi (8966 MPa).modulus—1,300,000 psi (8.96 GPa).
Flexural strength, ultimate—22 000ultimate—22,000 psi (152 MPa).
Flexural modulus—1 000 000 psi (6897 MPa).modulus—1,000,000 psi (6.90 GPa).
Glass content—30 %.
Thickness—0.30 in. (7.62 Thickness—0.29 in. (7.4 mm).
5. Materials
5.1 Resin Matrix System:
5.1.1 The resin shall be determined to be acceptable for the service either by test, see 8.6, or by verified case history.
5.1.2 Catalyst/Promoter System, shall be as recommended or approved by the resin producer.
5.1.3 Diluents, such as added styrene, fillers, dyes, pigments, or flame retardants shall be used only when agreed upon between
the fabricator and the buyer. When such items are required, limits for each shall be agreed upon between the fabricator and the
buyer. A thixotropic agent may be added to the resin for viscosity control.
NOTE 8—The addition of fillers, dyes, pigments, flame retardants, and thixotropic agents may interfere with visual inspection of laminate quality.
NOTE 9—Chemical resistance can be significantly affected by the catalyst/promoter system, diluents, dyes, fillers, flame retardants, or thixotropic agent
used in the resin.
5.1.4 Resin Pastes, used where necessary to fill crevices formed by joining subassemblies before overlay shall not be subject to
the limitations of 5.1.3. Pastes shall be made with thixotropic agents.
5.1.5 Ultraviolet Absorbers, may be added to the exterior surface for improved wea
...