ASTM F2968/F2968M-21 - 1.5.2021
 
1. Scope

1.1?This specification covers outside diameter controlled, metric-sized and inch-sized black or yellow crosslinked polyethylene (PEX) pipe, made in pipe dimension ratios ranging from 6 to 17, and pressure rated for gas distribution. Included are requirements and test methods for material, workmanship, dimensions, burst pressure, hydrostatic sustained pressure, stabilizer functionality, bent-pipe hydrostatic pressure, degree of crosslinking, chemical resistance, minimum operating temperature and squeeze-off. Requirements for pipe markings are also given. The pipe covered by this specification is intended for buried gas distribution and gas transmission pressure piping applications.

1.2?This specification also includes requirements for joints made between PEX pipe and polyethylene electrofusion fittings (specified in Specification F3373). Fittings to be used with PEX pipe manufactured to this specification are in Specification F2829/F2829M. Installation considerations are in X3.2.

Note 1:?Inch-sized fittings should not be used for metric-sized pipe, and metric-sized fittings should not be used for inch-sized pipe.

1.3?The text of this specification references notes, footnotes, and appendixes, which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification.

1.4?UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.5?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 and health practices and determine the applicability of regulatory limitations prior to use.

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

F1948-20

Standard Specification for Metallic Mechanical Fittings for Use on Outside Diameter Controlled Thermoplastic Gas Distribution Pipe and Tubing

ISO 14531-3

Plastics pipes and fittings -- Crosslinked polyethylene (PE-X) pipe systems for the conveyance of gaseous fuels -- Metric series -- Specifications -- Part 3: Fittings for mechanical jointing (including PE-X/metal transitions)

ISO 14531-2

Plastics pipes and fittings -- Crosslinked polyethylene (PE-X) pipe systems for the conveyance of gaseous fuels -- Metric series -- Specifications -- Part 2: Fittings for heat-fusion jointing

ISO 1167

Thermoplastics pipes, fittings and assemblies for the conveyance of fluids -- Determination of the resistance to internal pressure -- Part 1: General method

MIL-STD-129

Marking for Shipment and Storage

FED-STD-123

Marking for Shipment (Civil Agencies)

F2897-23a

Standard Specification for Tracking and Traceability Encoding System of Natural Gas Distribution Components (Pipe, Tubing, Fittings, Valves, and Appurtenances) (Includes all amendments and changes 11/3/2023).

D1505-18

Standard Test Method for Density of Plastics by the Density-Gradient Technique

D792-20

Standard Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement

D618-21

Standard Practice for Conditioning Plastics for Testing

D543-21

Standard Practices for Evaluating the Resistance of Plastics to Chemical Reagents

F1041-20

Standard Guide for Squeeze-Off of Polyolefin Gas Pressure Pipe and Tubing

D1600-18

Standard Terminology for Abbreviated Terms Relating to Plastics (Withdrawn 2024)

D1599-18

Standard Test Method for Resistance to Short-Time Hydraulic Pressure of Plastic Pipe, Tubing, and Fittings

D1598-23

Standard Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal Pressure

F876-24

Standard Specification for Crosslinked Polyethylene (PEX) Tubing

F412-23

Standard Terminology Relating to Plastic Piping Systems

D4218-20

Standard Test Method for Determination of Carbon Black Content in Polyethylene Compounds by the Muffle-Furnace Technique

D2837-22

Standard Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis for Thermoplastic Pipe Products

D2765-16(2024)

Standard Test Methods for Determination of Gel Content and Swell Ratio of Crosslinked Ethylene Plastics

D2290-19a

Standard Test Method for Apparent Hoop Tensile Strength of Plastic or Reinforced Plastic Pipe (Includes all amendments and changes 9/12/2019).

D1603-20

Standard Test Method for Carbon Black Content in Olefin Plastics

D2122-22

Standard Test Method for Determining Dimensions of Thermoplastic Pipe and Fittings

F1563-23

Standard Specification for Tools to Squeeze-off Polyethylene (PE) Gas Pipe or Tubing

F1055-16a(2022)

Standard Specification for Electrofusion Type Polyethylene Fittings for Outside Diameter Controlled Polyethylene and Crosslinked Polyethylene (PEX) Pipe and Tubing (Includes all amendments and changes 11/8/2022).