ASTM F1924-19

Standard Specification for Plastic Mechanical Fittings for Use on Outside Diameter Controlled Polyethylene Gas Distribution Pipe and Tubing

ABSTRACT
This specification describes requirements and test methods for the qualification of plastic bodied mechanical fittings for use with outside diameter controlled polyethylene (PE) gas distribution pipe, nominal 2 pipe size (IPS) and smaller. In addition, it specifies general requirements of the material from which these fittings are made. Unless otherwise specified, each nominal size of fitting shall be tested. Testing of the thickest wall pipe that the fitting is designed to be used with qualifies the use of that fitting with pipe of lesser wall thickness. In order to determine the overall performance of the mechanical fittings, the following tests shall be performed: elevated temperature sustained pressure test, tensile strength test, temperature cycling test, constant tensile load joint test (in-line joints only), and rotation test (mechanical saddle fittings only).
SCOPE
1.1 This specification describes requirements and test methods for the qualification of plastic bodied mechanical fittings for use with outside diameter controlled polyethylene (PE) gas distribution pipe, nominal 2 pipe size (IPS) and smaller complying with Specification D2513. In addition, it specifies general requirements of the material from which these fittings are made.  
1.2 The test methods described in this specification are not intended to be used as routine quality control tests.  
1.3 This specification covers the types of mechanical fittings described in 3.2.  
1.4 The text of this specification references notes and footnotes, which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this specification.  
1.5 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.  
1.6 The following safety hazards caveat pertains only to the test method portion, Section 7, 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.  
1.7 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-2019
• ICS: 23.040.45 - Plastics fittings
• Technical Committee: F17 - Plastic Piping Systems
• Drafting Committee: F17.60 - Gas

Relations

• Replaces: ASTM F1924-12 - Standard Specification for Plastic Mechanical Fittings for Use on Outside Diameter Controlled Polyethylene Gas Distribution Pipe and Tubing
• Effective Date: 01-Aug-2019
• Refers: ASTM F2897-23a - Standard Specification for Tracking and Traceability Encoding System of Natural Gas Distribution Components (Pipe, Tubing, Fittings, Valves, and Appurtenances)
• Effective Date: 01-Nov-2023
• Refers: ASTM F412-20 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Apr-2020
• Refers: ASTM F1588-96(2019) - Standard Test Method for Constant Tensile Load Joint Test (CTLJT)
• Effective Date: 01-Nov-2019
• Refers: ASTM F412-19 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Jan-2019
• Refers: ASTM D2513-18 - Standard Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings
• Effective Date: 15-Apr-2018
• Refers: ASTM D1600-18 - Standard Terminology for Abbreviated Terms Relating to Plastics (Withdrawn 2024)
• Effective Date: 01-Jan-2018
• Refers: ASTM F412-17a - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Aug-2017
• Refers: ASTM F412-17 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Feb-2017
• Refers: ASTM D2513-16a - Standard Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings
• Effective Date: 15-Dec-2016
• Refers: ASTM D2513-16 - Standard Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings
• Effective Date: 01-Dec-2016
• Refers: ASTM F412-16a - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 15-Nov-2016
• Refers: ASTM F412-16 - Standard Terminology Relating to Plastic Piping Systems
• Effective Date: 01-Aug-2016
• Refers: ASTM D1598-15 - Standard Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal Pressure
• Effective Date: 01-Nov-2015
• Refers: ASTM F1588-96(2015) - Standard Test Method for Constant Tensile Load Joint Test (CTLJT)
• Effective Date: 01-Aug-2015

Overview

ASTM F1924-19 is a key specification developed by ASTM International that sets the requirements and test methods for plastic mechanical fittings used on outside diameter controlled polyethylene (PE) gas distribution pipes and tubing, up to 2-inch nominal pipe size (IPS) and smaller. The standard ensures these plastic mechanical fittings provide safe, reliable connections in natural gas distribution systems, complying with rigorous material and performance criteria. Adherence to ASTM F1924-19 supports both safety and regulatory compliance in gas piping installations.

Key Topics

• Scope and Purpose

  • Applies to plastic-bodied mechanical fittings for PE gas distribution pipes and tubing, specifically for pipes that comply with ASTM D2513.
  • The specification covers material properties, performance qualifications, and evaluation methods for mechanical fittings.
  • Includes fittings for nominal 2-inch IPS and smaller, encompassing both pipe and tubing.

• Material Requirements

  • Specifies that pressure-containing materials must have defined long-term strength, such as hydrostatic strength determined in accordance with ASTM methods.
  • Materials should demonstrate resistance to environmental stress, chemical exposure, and potential degradation from natural gas or external contaminants.

• Performance Testing

  • Elevated temperature sustained pressure testing, tensile strength testing, temperature cycling tests, constant tensile load joint tests (for in-line joints), and rotation tests (for mechanical saddle fittings) are required.
  • Fittings must meet stringent requirements to ensure leak-tightness, structural integrity, and durability across varied installation and service conditions.

• Product Marking and Traceability

  • Requires standardized product identification, material codes, manufacturer details, and a unique tracking code for component traceability.
  • Markings must be clear, durable, and compliant with both ASTM and regulatory guidelines.

Applications

ASTM F1924-19 plays a crucial role in:

• Natural Gas Distribution
  Ensuring safe and compliant connections for outside diameter controlled polyethylene gas piping systems in residential, commercial, and light industrial gas distribution networks.

• Municipal Gas Infrastructure
  Used by utilities and contractors for new installations, repairs, and system upgrades. The fittings support reliable joining of PE pipes where fusion is not feasible or as a complement to fusion technologies.

• Regulatory Compliance Fittings qualified under this standard help organizations meet requirements of US Pipeline Safety Regulations (CFR Title 49 Part 192), as well as other international codes for plastic piping systems.

• Traceability and Quality Assurance Enables accurate tracking of components throughout their lifecycle. Enhanced traceability aids in system maintenance, recalls, and quality verification.

Related Standards

Organizations referencing or working with ASTM F1924-19 should also consider:

• ASTM D2513: Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings
• ASTM D1598: Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal Pressure
• ASTM D638: Test Method for Tensile Properties of Plastics
• ASTM F412: Terminology Relating to Plastic Piping Systems
• ASTM F1588: Test Method for Constant Tensile Load Joint Test
• ASTM F2897: Specification for Tracking and Traceability Encoding System of Gas Distribution Components
• ASME B31.8: Gas Transmission and Distribution Piping Systems
• CFR Title 49 Part 192: US Pipeline Safety Regulations
• PPI TR-4: Recommended Hydrostatic Strengths and Design Stresses for Thermoplastic Pipe and Fittings Compounds

Meeting the specifications of ASTM F1924-19 ensures that plastic mechanical fittings for polyethylene gas distribution pipes deliver performance, durability, and compliance demanded by the natural gas industry worldwide. Using products meeting this standard is essential for gas utilities, contractors, and engineers focused on safety, reliability, and regulatory adherence in gas distribution piping systems.

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:F1924 −19 An American National Standard
Standard Specification for
Plastic Mechanical Fittings for Use on Outside Diameter
Controlled Polyethylene Gas Distribution Pipe and Tubing
This standard is issued under the fixed designation F1924; 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.
1. Scope* 2. Referenced Documents
2.1 ASTM Standards:
1.1 Thisspecificationdescribesrequirementsandtestmeth-
D638Test Method for Tensile Properties of Plastics
ods for the qualification of plastic bodied mechanical fittings
D1598Test Method for Time-to-Failure of Plastic Pipe
for use with outside diameter controlled polyethylene (PE) gas
Under Constant Internal Pressure
distribution pipe, nominal 2 pipe size (IPS) and smaller
D1600TerminologyforAbbreviatedTermsRelatingtoPlas-
complying with Specification D2513. In addition, it specifies
tics
general requirements of the material from which these fittings
D2513Specification for Polyethylene (PE) Gas Pressure
are made.
Pipe, Tubing, and Fittings
1.2 The test methods described in this specification are not
D2837Test Method for Obtaining Hydrostatic Design Basis
intended to be used as routine quality control tests.
forThermoplasticPipeMaterialsorPressureDesignBasis
for Thermoplastic Pipe Products
1.3 Thisspecificationcoversthetypesofmechanicalfittings
F412Terminology Relating to Plastic Piping Systems
described in 3.2.
F1588Test Method for Constant Tensile Load Joint Test
1.4 The text of this specification references notes and
(CTLJT)
footnotes,whichprovideexplanatorymaterial.Thesenotesand
F2897Specification for Tracking and Traceability Encoding
footnotes (excluding those in tables and figures) shall not be
System of Natural Gas Distribution Components (Pipe,
considered as requirements of this specification.
Tubing, Fittings, Valves, and Appurtenances)
2.2 ASME Standard:
1.5 Thevaluesstatedininch-poundunitsaretoberegarded
ASME B31.8Gas Transmission and Distribution Piping
as standard. The values given in parentheses are mathematical
Systems
conversions to SI units that are provided for information only
2.3 Federal Standard:
and are not considered standard.
CFR, Title 49, Part 192 Pipeline Safety Regulations
1.6 The following safety hazards caveat pertains only to the
2.4 Plastics Pipe Institute Standard:
test method portion, Section 7, of this specification. This
PPI TR-4Recommended Hydrostatic Strengths and Design
standard does not purport to address all of the safety concerns,
Stresses forThermoplastic Pipe and Fittings Compounds
if any, associated with its use. It is the responsibility of the user
of this standard to establish appropriate safety, health, and 3. Terminology
environmental practices and determine the applicability of
3.1 Definitions—Definitions of terms used in this specifica-
regulatory limitations prior to use.
tionareinaccordancewithTerminologyF412unlessotherwise
1.7 This international standard was developed in accor-
specified. Abbreviations are in accordance with Terminology
dance with internationally recognized principles on standard-
D1600 unless otherwise specified.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
mendations issued by the World Trade Organization Technical
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Barriers to Trade (TBT) Committee.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Available from American Society of Mechanical Engineers (ASME), ASME
International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
This specification is under the jurisdiction ofASTM Committee F17 on Plastic www.asme.org.
Piping Systems and is the direct responsibility of Subcommittee F17.60 on Gas. Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
Current edition approved Aug. 1, 2019. Published August 2019. Originally Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
approved in 1998. Last previous edition approved in 2012 as F1924–12. DOI: Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825,
10.1520/F1924-19. Irving, TX 75062, http://www.plasticpipe.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
F1924−19
3.1.1 The Gas Industry terminology used in this specifica- 4. Materials and Manufacture Requirements
tion is in accordance withASME B31.8 or CFR, Title 49, Part
4.1 Plastic pressure containing materials subject to continu-
192 unless otherwise indicated.
ous stress, either hoop or axial, shall have an ASTM material
3.1.2 The term “pipe” used herein refers to both “pipe” and
specification, and the materials long-term strength, such as the
“tubing”unlessspecificallystatedotherwise.Theterm“fitting”
long-term hydrostatic strength, determined in accordance with
refers to a mechanical connecting device as described in 3.1.4
TestMethodD2837,exceptingthatfailuredatacanbeobtained
and 3.1.6. from specimens such as the following: tensile bars, plane
strain, or actual fitting samples.Amaterial listing in PPI TR-4
3.1.3 joint, n—thelocationatwhichtwopiecesofpipe,ora
document is evidence of compliance with this paragraph for
pipe and a fitting are connected together, for example, an
third party certifying and listing agencies.
installed coupling has two joints.
3.1.4 joint, mechanical, n—a connection between piping 4.2 Thephysicalpropertiesofeachmaterialusedtoproduce
thefittingshallbeavailablefromthefittingmanufacturerupon
components employing physical force to develop a seal or
request.
produce alignment.
3.1.5 long-term strength (LTS), n—the estimated tensile
4.3 Specifications outlining all the physical properties and
stress that when applied continuously will cause failure at
effects of environmental conditions for materials of manufac-
100000 h. This is the intercept of the stress regression line
ture shall be available from the fitting manufacturer upon
with the 100000 h coordinate.
request.
3.1.6 mechanical fitting, n—fitting for making a mechanical
NOTE1—Materialsinlong-termcontactwithnaturalgasoflinequality
joint to provide for pressure integrity, leak tightness, and
and LP gas vapor should be demonstrated not to adversely affect the
performance of the fitting.
depending on category, as defined in this specification, resis-
NOTE 2—Materials should have a demonstrated resistance to environ-
tance to end loads.
mental stress cracking when exposed, under stress, to chemical com-
3.1.6.1 category 1 mechanical fitting, n—fitting for assem-
pounds encountered in, or external to gas piping systems, and a demon-
bling pipes, which includes a compression zone(s) to provide
strated resistance to bacteriological decomposition. Such compounds
include, but are not limited to, ice thawing chemicals, fertilizers,
for pressure integrity, leak tightness, and resistance to end
insecticides, herbicides, leak detection fluids, acids, bases and antifreeze
loadssufficienttocausenolessthan25%elongationofthePE
solutions used to thaw frozen lines. The effects of liquid environments,
piping as described in this specification.
such as antifreeze agents, odorants, and hydrocarbons are known to be
deleterious to some plastics, particularly when under service conditions.
3.1.6.2 category 2 mechanical fitting, n—fitting for assem-
bling pipes, which includes a compression zone(s) to provide
5. Dimensions
for pressure integrity and leak tightness only. Category 2
fittings do not provide for resistance to end loads.
5.1 The dimensions and tolerances shall be determined by
3.1.7 MAOP, n—the Maximum Allowable Operating Pres-
the manufacturer.
sure of the fuel gas piping system, in psig, as determined in
accordance with CFR, Title 49, Part 192.121 and as repre- 6. Qualification Requirements
sented in the following:
6.1 General—Unlessotherwisespecified,eachnominalsize
MAOP 5 P 52 3S/ R 21 3f (1)
~ ! of fitting shall be tested. Testing of the thickest wall pipe that
D
the fitting is designed to be used with qualifies the use of that
where:
fitting with pipe of lesser wall thickness.
S = the PE material’s HDB as published in PPI TR-4.
6.1.1 Mechanical joint qualifications shall be performed on
R = the pipe’s dimension ratio determined by dividing the
assembled joints using the fitting manufacturer’s joining pro-
pipe’sspecifiednominaloutsidediameterbythepipes
cedure. All mechanical fittings offered by the manufacturer
specified nominal wall thickness; and,
shall be capable of meeting the requirements of this standard
f = the design (derating) factor for thermoplastic fuel gas
D
when connecting polyethylene gas piping complying with
piping as set by the authority having jurisdiction. In
Specification D2513. To verify the structural integrity of the
the United States the design factor is cited in CFR,
fitting body, representative samples shall be subjected to the
Title 49 Part 192.121.
requirementsof6.2.1.Itisnottheintentofthisspecificationto
3.2 Types of Mechanical Fittings:
require testing of all fitting configurations, that is, tees, ells,
3.2.1 in-line fitting, n—mechanical fitting used to make a etc., but each mechanical joint design in each size.
mechanical joint where the bore axis of the compression and
6.1.2 All mechanical fittings described in 3.2 shall have an
sealing zones of the fitting is essentially the same as the
internal pipe reinforcing tubular insert stiffener that extends at
connected piping, for example, couplings, ells, and tees. least under the seal and gripping device, where used. The
saddle portion of saddle-type fittings do not require an internal
3.2.2 mechanical saddle fitting, n—mechanical fitting used
tubular stiffener due to the nature of the connection.
to make a mechanical joint that allows a lateral connection to
an existing main in which a portion of the fitting is contoured 6.2 Performance Requirements:
to match the O.D. of the pipe to which it is attached. Herein
6.2.1 Elevated Temperature Sustained Pressure—The
referred to as the saddle fitting mating pipe. fitting, joint or pipe in the area affected by the fitting shall not
F1924−19
TABLE 1 Elevated Temperature Sustained Pressure Test
fail as defined in Test Method D1598, when tested in accor-
Conditions
dancewith7.2.Thefittingorjointmeetsthisrequirementwhen
Condition Minimum Time Temperature Pipe Hoop Stress, S
testedinaccordancewithanyoneofthethreeconditions(A,B,
A 3 000 h 140±4°F 1 000 psi (6.8 MPa)
or C) listed in 7.2.
(60± 2°C)
6.2.2 Tensile Strength—The pipe joint shall accommodate
B 1 000 h 176±4°F 580 psi (4.0 MPa)
the tensile loadings when tested in accordance with 7.3. (80± 2°C)
C 170 h 176±4°F 670 psi (4.6 MPa)
...

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: F1924 − 12 F1924 − 19 An American National Standard
Standard Specification for
Plastic Mechanical Fittings for Use on Outside Diameter
Controlled Polyethylene Gas Distribution Pipe and Tubing
This standard is issued under the fixed designation F1924; 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.
1. Scope*
1.1 This specification describes requirements and test methods for the qualification of plastic bodied mechanical fittings for use
with outside diameter controlled polyethylene (PE) gas distribution pipe, nominal 2 pipe size (IPS) and smaller complying with
Specification D2513. In addition, it specifies general requirements of the material from which these fittings are made.
1.2 The test methods described in this specification are not intended to be used as routine quality control tests.
1.3 This specification covers the types of mechanical fittings described in 3.2.
1.4 The text of this specification references notes and footnotes, which provide explanatory material. These notes and footnotes
(excluding those in tables and figures) shall not be considered as requirements of this specification.
1.5 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.
1.6 The following safety hazards caveat pertains only to the test method portion, Section 7, 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.
1.6 The text of this specification references notes and footnotes, which provide explanatory material. These notes and footnotes
(excluding those in tables and figures) shall not be considered as requirements of this specification.
1.7 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:
D638 Test Method for Tensile Properties of Plastics
D1598 Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal Pressure
D1600 Terminology for Abbreviated Terms Relating to Plastics
D2513 Specification for Polyethylene (PE) Gas Pressure Pipe, Tubing, and Fittings
D2837 Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis for
Thermoplastic Pipe Products
F412 Terminology Relating to Plastic Piping Systems
F1588 Test Method for Constant Tensile Load Joint Test (CTLJT)
F2897 Specification for Tracking and Traceability Encoding System of Natural Gas Distribution Components (Pipe, Tubing,
Fittings, Valves, and Appurtenances)
2.2 ASME Standard:
ASME B31.8 Gas Transmission and Distribution Piping Systems
This specification is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.60 on Gas.
Current edition approved April 1, 2012Aug. 1, 2019. Published May 2012August 2019. Originally approved in 1998. Last previous edition approved in 20112012 as
F1924–05(2011).F1924–12. DOI: 10.1520/F1924-12.10.1520/F1924-19.
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.
Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, ThreeTwo Park Ave., New York, NY 10016-5990,
http://www.asme.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
F1924 − 19
2.3 Federal Standard:
CFR, Title 49, Part 192 Pipeline Safety Regulations
2.4 Plastics Pipe Institute Standard:
PPI TR-4 Recommended Hydrostatic Strengths and Design Stresses for Thermoplastic Pipe and Fittings Compounds
3. Terminology
3.1 Definitions—Definitions of terms used in this specification are in accordance with Terminology F412 unless otherwise
specified. Abbreviations are in accordance with Terminology D1600 unless otherwise specified.
3.1.1 The Gas Industry terminology used in this specification is in accordance with ASME B31.8 or CFR, Title 49, Part 192
unless otherwise indicated.
3.1.2 The term “pipe” used herein refers to both “pipe” and “tubing” unless specifically stated otherwise. The term “fitting”
refers to a mechanical connecting device as described in 3.1.4 and 3.1.6.
3.1.3 joint, n—the location at which two pieces of pipe, or a pipe and a fitting are connected together, for example, an installed
coupling has two joints.
3.1.4 joint, mechanical, n—a connection between piping components employing physical force to develop a seal or produce
alignment.
3.1.5 long-term strength (LTS), n—the estimated tensile stress that when applied continuously will cause failure at 100 000 h.
This is the intercept of the stress regression line with the 100 000 h coordinate.
3.1.6 mechanical fitting, n—fitting for making a mechanical joint to provide for pressure integrity, leak tightness, and depending
on category, as defined in this specification, resistance to end loads.
3.1.6.1 category 1 mechanical fitting, n—fitting for assembling pipes, which includes a compression zone(s) to provide for
pressure integrity, leak tightness, and resistance to end loads sufficient to cause no less than 25 % elongation of the PE piping as
described in this specification.
3.1.6.2 category 2 mechanical fitting, n—fitting for assembling pipes, which includes a compression zone(s) to provide for
pressure integrity and leak tightness only. Category 2 fittings do not provide for resistance to end loads.
3.1.7 MAOP, n—the Maximum Allowable Operating Pressure of the fuel gas piping system, in psig, as determined in accordance
with CFR, Title 49, Part 192.121 and as represented in the following:
MAOP 5 P 5 23S/~R 2 1!3f (1)
D
where:
S = the PE material’s HDB as published in PPI TR-4.
R = the pipe’s dimension ratio determined by dividing the pipe’s specified nominal outside diameter by the pipes specified
nominal wall thickness; and,
f = the design (derating) factor for thermoplastic fuel gas piping as set by the authority having jurisdiction. In the United States
D
the design factor is cited in CFR, Title 49 Part 192.121.
3.2 Types of Mechanical Fittings:
3.2.1 in-line fitting, n—mechanical fitting used to make a mechanical joint where the bore axis of the compression and sealing
zones of the fitting is essentially the same as the connected piping, for example, couplings, ells, and tees.
3.2.2 mechanical saddle fitting, n—mechanical fitting used to make a mechanical joint that allows a lateral connection to an
existing main in which a portion of the fitting is contoured to match the O.D. of the pipe to which it is attached. Herein referred
to as the saddle fitting mating pipe.
4. Materials and Manufacture Requirements
4.1 Plastic pressure containing materials subject to continuous stress, either hoop or axial, shall have an ASTM material
specification, and the materials long-term strength, such as the long-term hydrostatic strength, determined in accordance with Test
Method D2837, excepting that failure data can be obtained from specimens such as the following: tensile bars, plane strain, or
actual fitting samples. A material listing in PPI TR-4 document is evidence of compliance with this paragraph for third party
certifying and listing agencies.
4.2 The physical properties of each material used to produce the fitting shall be available from the fitting manufacturer upon
request.
4.3 Specifications outlining all the physical properties and effects of environmental conditions for materials of manufacture shall
be available from the fitting manufacturer upon request.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, DLA Document Services, Building 4/D, 700 Robbins Ave., Philadelphia, PA
19111-5098, http://dodssp.daps.dla.mil.19111-5094, http://quicksearch.dla.mil.
Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825, Irving, TX 75062, http://www.plasticpipe.org.
F1924 − 19
NOTE 1—Materials in long-term contact with natural gas of line quality and LP gas vapor should be demonstrated not to adversely affect the
performance of the fitting.
NOTE 2—Materials should have a demonstrated resistance to environmental stress cracking when exposed, under stress, to chemical compounds
encountered in, or external to gas piping systems, and a demonstrated resistance to bacteriological decomposition. Such compounds include, but are not
limited to, ice thawing chemicals, fertilizers, insecticides, herbicides, leak detection fluids, acids, bases and antifreeze solutions used to thaw frozen lines.
The effects of liquid environments, such as antifreeze agents, odorants, and hydrocarbons are known to be deleterious to some plastics, particularly when
under service conditions.
5. Dimensions
5.1 The dimensions and tolerances shall be determined by the manufacturer.
6. Qualification Requirements
6.1 General—Unless otherwise specified, each nominal size of fitting shall be tested. Testing of the thickest wall pipe that the
fitting is designed to be used with qualifies the use of that fitting with pipe of lesser wall thickness.
6.1.1 Mechanical joint qualifications shall be performed on assembled joints using the fitting manufacturer’s joining procedure.
All mechanical fittings offered by the manufacturer shall be capable of meeting the requirements of this standard when connecting
polyethylene gas piping complying with Specification D2513. To verify the structural integrity of the fitting body, representative
samples shall be subjected to the requirements of 6.2.1. It is not the intent of this specification to require testing of all fitting
configurations, that is, tees, ells, etc., but each mechanical joint design in each size.
6.1.2 All mechanical fittings described in 3.2 shall have an internal pipe reinforcing tubular insert stiffener that extends at least
under the seal and gripping device, where used. The saddle portion of saddle-type fittings do not require an internal tubular stiffener
due to the nature of the connection.
6.2 Performance Requirements:
6.2.1 Elevated Temperature Sustained Pressure—The fitting, joint or pipe in the area affected by the fitting shall not fail as
defined in Test Method D1598, when tested in accordance with 7.2. The fitting or joint meets this requirement when tested in
accordance with any one of the three conditions (A, B, or C) listed in 7.2.
6.2.2 Tensile Strength—The pipe joint shall accommodate the tensile loadings when tested in accordance with 7.3.
6.2.2.1 In-Line Fittings, Category 1—The joint shall provide resistance to a force on the pipe joint equal to or greater than that
which will cause no less than 25 % elongation of pipe, or the pipe fails outside the joint area when tested
...