ASTM F2785-09

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An American National Standard
Designation: F2785 – 09
Standard Specification for
Polyamide 12 Gas Pressure Pipe, Tubing, and Fittings
This standard is issued under the fixed designation F2785; 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 2. Referenced Documents
1.1 This specification covers requirements and test methods 2.1 ASTM Standards:
for the characterization of polyamide 12 pipe, tubing, and D543 Practices for Evaluating the Resistance of Plastics to
fittings for use in fuel gas mains and services for direct burial Chemical Reagents
and reliner applications. The pipe and fittings covered by this D618 Practice for Conditioning Plastics for Testing
specification are intended for use in the distribution of natural D638 Test Method for Tensile Properties of Plastics
gas. D789 Test Methods for Determination of Solution Viscosi-
1.1.1 This specification does not cover threaded pipe. Ge- ties of Polyamide (PA)
neric fusion guidelines are given in Appendix X1. Design D1598 Test Method for Time-to-Failure of Plastic Pipe
considerations are discussed in Appendix X2. In-plant quality Under Constant Internal Pressure
control programs are specified in Annex A1. D1599 TestMethodforResistancetoShort-TimeHydraulic
1.2 Thetextofthisspecificationreferencesnotes,footnotes, Pressure of Plastic Pipe, Tubing, and Fittings
and appendixes which provide explanatory material. These D1898 Practice for Sampling of Plastics
notesandfootnotes(excludingthoseintablesandfigures)shall D1600 Terminology for Abbreviated Terms Relating to
not be considered as requirements of the specification. Plastics
1.3 The values stated in inch-pound units are to be regarded D2122 Test Method for Determining Dimensions of Ther-
as standard. The values given in parentheses are mathematical moplastic Pipe and Fittings
conversions to SI units that are provided for information only D2774 Practice for Underground Installation of Thermo-
and are not considered standard. plastic Pressure Piping
1.4 This standard does not purport to address all of the D2290 Test Method for Apparent Hoop Tensile Strength of
safety concerns, if any, associated with its use. It is the Plastic or Reinforced Plastic Pipe by Split Disk Method
responsibility of the user of this standard to establish appro- D2837 TestMethodforObtainingHydrostaticDesignBasis
priate safety and health practices and determine the applica- forThermoplastic Pipe Materials or Pressure Design Basis
bility of regulatory limitations prior to use. for Thermoplastic Pipe Products
D4066 Classification System for Nylon Injection and Ex-
NOTE 1—Pipe and fittings utilizing heat fusion joining techniques
trusion Materials (PA)
produced from compounds meeting the requirements of Group 3, Class 2,
D6779 Classification System for Polyamide Molding and
andGrade3(PA323orPA11)areintendedforusewithpipemanufactured
from compounds meeting the requirements of Group 3, class 2 and Grade Extrusion Materials (PA)
3. Pipe and fittings utilizing heat fusion joining techniques produced from
F412 Terminology Relating to Plastic Piping Systems
compoundsmeetingtherequirementsofGroup4,Class2andGrade3(PA
F1025 Guide for Selection and Use of Full-Encirclement-
423 or PA12) are intended for use with pipe manufactured from com-
Type Band Clamps for Reinforcement or Repair of Punc-
pounds meeting the requirements of Group 4, Class 2 and Grade 3.As per
tures or Holes in Polyethylene Gas Pressure Pipe
the recommendations of the respective resin manufacturers, no cross
F1473 Test Method for Notch Tensile Test to Measure the
fusion between PA 323 (PA11) and PA 423 (PA12) compounds is
Resistance to Slow Crack Growth of Polyethylene Pipes
permitted.
and Resins
F1733 Specification for Butt Heat Fusion Polyamide(PA)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This test method is under the jurisdiction of ASTM Committee F17 on Plastic Standards volume information, refer to the standard’s Document Summary page on
Piping Systems and is the direct responsibility of Subcommittee F17.60 on Gas. the ASTM website.
Current edition approved Aug. 1, 2009. Published September 2009. DOI: Withdrawn. The last approved version of this historical standard is referenced
10.1520/F2785-09. on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F2785 – 09
Plastic Fitting for Polyamide(PA) Plastic Pipe and Tubing 3.2 The gas industry terminology used in this specification
F1973 Specification for Factory Assembled Anodeless Ris- is in accordance withANSI B 31.8 or CFR OPS Part 192 Title
ers and Transition Fittings in Polyethylene (PE) and 49, unless otherwise indicated.
Polyamide 11 (PA11) and Polyamide 12 (PA12) Fuel Gas 3.3 The term pipe used herein refers to both pipe and tubing
Distribution Systems
unless specifically stated otherwise.
F2138 SpecificationforExcessFlowValvesforNaturalGas
3.4 Definitions of Terms Specific to This Standard:
Service
3.5 re-rounding equipment, n—equipment used to reform
F2145 Specification for Polyamide 11 (PA 11) and Polya-
the pipe and permanently reduce ovality to 5% or less.
mide 12 (PA12) Mechanical Fittings for Use on Outside
3.6 rounding equipment, n—equipment, devices, clamps,
Diameter Controlled Polyamide 11 and Polyamide 12 Pipe
and so forth, used to temporarily hold the pipe round while
and Tubing
out-of-roundness measurements are made, or a joining proce-
F2767 Specification for Electrofusion Type Polyamide-12
dure (heat fusion, electrofusion, or mechanical) is performed.
Fittings for Outside Diameter Controlled Polyamide-12
3.7 standard thermoplastic material designated code,
Pipe and Tubing for Gas Distribution
n—the pipe material designation code shall consist of the
2.2 ANSI Standards:
abbreviation for the polyamide (PA) followed by Arabic
B 16.40 Manually Operated Thermoplastic Gas Shutoffs
numerals which describe the short term properties in accor-
and Valves in Gas Distribution Systems
dance with Classifications D4066 or D6779, the hydrostatic
B 31.8 Gas Transmission and Distribution Piping Systems
designstressforwaterat73.4°F(23°C)inunitsof100psiwith
2.3 Federal Specifications:
any decimal figures dropped. Where the hydrostatic design
Fed. Std. No. 123 Marking for Shipment (Civil Agencies)
stress code contains less than two figures, a zero is used before
OPSPart192Title49 ,Title49CodeofFederalRegulations
the number. Thus, a complete material designation code shall
2.4 Military Standards:
consist of two letters and five figures for polyamide pipe
MIL-STD-129 Marking for Shipment and Storage
materials. For example, PA 42316 is a grade of polyamide 12
MIL-STD-1235 (ORD) Single- and Multi-Level Continu-
with a 1600 psi design stress for water at 73.4°F (23°C). The
ous Sampling Procedures and Tables for Inspection by
hydrostatic design stresses for gas are not used in this desig-
Attributes
nation code.
2.5 ISO Standards:
3.8 thermoplasticpipedimensionratio(DR),n—theratioof
ISO 22621 Part 1 Plastics piping systems for the supply of
pipe diameter to wall thickness. It is calculated by dividing the
gaseous fuels for maximum operating pressure up to and
specified outside diameter of the pipe, in inches, by the
including 2 MPa (20 bar) – Polyamide (PA) : General
minimum specified wall thickness, in inches. The standard
2.6 Plastic Pipe Institute:
dimension ratio (SDR) is a common numbering system which
PPI TR3 Policies and Procedures for Developing Hydro-
is derived from the ANSI preferred number series R 10.
static Design Basis (HDB), Pressure Design Basis (PDB),
3.9 toe-in, n—a small reduction of the outside diameter at
Strength Design Basis (SDB), and Minimum Required
the cut end of a length of thermoplastic pipe.
Strength (MRS) Ratings for Thermoplastic Piping Mate-
rials or Pipe
4. Requirements for Materials
PPI TR4 Hydrostatic Design Bases and Maximum Recom-
4.1 General—The polyamide material used to make pipe
mended Hydrostatic Design Stresses for Thermoplastic
and fittings shall be virgin or reworked material (see 4.5 ) and
Piping Materials
shall have a Plastics Pipe Institute (PPI) long-term hydrostatic
PPI TN7 Nature of Hydrostatic Stress Rupture Curves
design stress and hydrostatic design basis rating as determined
2.7 Other Standards:
per PPI TR3 and PPI TR4.
National Fire Protection Association: NFPA 58 , Storage
4.2 Classification—Polyamide materials suitable for use in
and Handling Liquefied Petroleum Gases
the manufacturing of pipe and fittings under this specification
3. Terminology
shall be classified in accordance with Classifications D4066
and D6779, as shown in Table 1.
3.1 Definitions—Definitions are in accordance with Termi-
4.3 Short- and Long-Term Properties—Polyamide pipe and
nology F412, and abbreviations are in accordance with Termi-
fittings shall be made from a PA material which also satisfies
nology D1600, unless otherwise specified.
the combinations of short- and long-term property require-
ments shown in Table 2.
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4.4 Resistance to Rapid Crack Propagation (RCP) for
4th Floor, New York, NY 10036, http://www.ansi.org.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
Materialsl—The material classification (formulation) used in
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
the manufacture of pipe and fittings under this specification
www.dodssp.daps.mil.
6 shall be tested for resistance to failure by RCP in accordance
Available from International Organization for Standardization (ISO), 1, ch. de
with 6.7. The data obtained shall be made available upon
la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
www.iso.ch.
request without limitations on disclosure, and shall not subse-
Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825,
quently be subject to disclosure limitations when used by
Irving, TX 75062, http://www.plasticpipe.org.
others. The values obtained are applicable to all pipes with the
Available from National Fire Protection Association (NFPA), 1 Batterymarch
Park, Quincy, MA 02169-7471, http://www.nfpa.org. wall thickness of the pipe tested and all thinner wall pipes.
F2785 – 09
TABLE 1 Classifications D4066 and D6779
5.2 Workmanship—The pipe and fittings shall be homoge-
Classification Designation neous throughout and free of visible cracks, holes, foreign
inclusion, blisters, and dents, or other injurious defects. The
PA Polyamide
4 (group) 12 nylon
pipe and fittings shall be as uniform as commercially practi-
2 (class) Heat stabilized
cable in color, opacity, density, and other physical properties.
3 (grade)
Relative viscosity, min 2.06
5.3 Pipe and Tubing Dimensions and Tolerances:
Melt point, °C 170–195
5.3.1 Dimension—The dimensions shall be specified by
Specification D789
Specific gravity 1.00–1.06
wall thickness and outside diameter.
Tensile strength, min, 35
5.3.1.1 Diameters—The outside diameter shall meet the
Test Method D638
MPa
requirements given in Table 3 or Table 4 when measured in
Elongation (ultimate), min, 150
accordance with 6.5.
%
Flexural modulus, min, 1000
5.3.1.2 Toe-In—Whenmeasuredinaccordancewith6.5.1.1,
Test Method D638
theoutsidediameteratthecutendofthepipeshallnotbemore
Mpa
than 1.5 % smaller than the undistorted outside diameter.
Charpy or Izod impact 25
resistance, min, J/M
Measurementoftheundistortedoutsidediametershallbemade
Deflection temperature, 35
no closer than 1.5 pipe diameters or 11.8 in. (300 mm),
Test Method D638
whichever distance is less, from the cut end of the pipe.
min at 1.82 Mpa
Moisture “as received”, %, 0.10
Undistorted outside diameter shall meet the requirements of
max
Table 3 or Table 4.
Specification D789
5.3.1.3 Wall Thickness—The wall thickness shall be as
specified in Table 4 or Table 5 when measured in accordance
TABLE 2 Short and Long Term Property Requirements
with 6.5.1.2. The minimum wall thickness at any point of
PA Material Short-Term in Long-Term in
measurementshallbenotlessthantheminimumwallthickness
Designation Code Accordance with Accordance with
specified in Table 4 or Table 5.
D4066 or D6779 D2837
5.3.1.4 Wall Thickness Eccentricity Range— The wall
PA42316 PA423 HDB of 3150 psi
thickness eccentricity range shall be within 12 % when
for 73°F (23°C)
measured in accordance with 6.5.1.3.
5.3.1.5 Ovality—The ovality (cross section) of 3 in. IPS
4.5 Rework Material—Clean rework material of the same
(88.9 mm) and smaller pipe shall not exceed 5 % when
commercial designation, generated from the manufacturer’s
measured in accordance with 6.5.3. Measurements of coiled
own pipe and fitting production shall not be used unless the
pipe shall be made on a sample cut from the coil, and in case
pipe and fittings produced meet all the requirements of this
of disagreement, conditioned per 6.3.
specification.
4.6 Documentation—A documentation system to allow for NOTE 2—Other factors, that is, installation compaction, static soil
loading, and dynamic vehicular loads may increase the ovality; therefore,
traceability of raw materials including percentage and material
5 % was chosen as the limit for the amount contributed by manufacturing,
classification(ordesignation,ifapplicable)ofreworkmaterials
packing, in-plant storage, and shipping.
used in the manufacture of the pipe product meeting the
(1) Before or during installation, coiled pipe larger than 3 in. IPS (88.9
requirements of this specification shall exist and be supplied to
mm) shall be processed by the installer through re-rounding equipment
the purchaser, if requested.
that corrects ovality to 5% or less.
NOTE 3—Ovality is a packaging condition that occurs when roundable
5. Requirements for Pipe and Fittings
pipe is wound into a coil—the pipe flattens out as it is coiled. Ovality is
5.1 General—Pipe shall be supplied in either coils or
corrected when joining equipment is applied to roundable pipe, or by field
straight lengths.Any pipe supplied in coils must meet the same
processing roundable pipe through re-rounding and straightening equip-
requirements before and after coiling. ment during installation.
TABLE 3 Outside Diameters and Tolerances for PA12 Pipe, in. (mm)
Nominal Pipe Size Outside Diameter Tolerance Maximum out-of-roundness
(SDR 13.5 SDR 11)
⁄2 0.840 (21.3) 60.004 (60.102) 0.016(0.406)
⁄4 1.050 (26.7) 60.004 (60.102) 0.02(0.508
...