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Tech News
Plastic Pipe Fittings Standards Promote Sound Connection of Gas Lines
“Thousands of miles of plastic gas distribution piping are installed
in the U.S. every year,” said Consultant Raymond Henrich, a retired
senior research scientist with Reliant Energy Minnegasco, Minn.,
and chairman of ASTM Subcommittee F17.60 on Gas. “Reliable joints
between pipes are essential for these installations to operate
safely. Natural gas pipe joints must resist leaking and pull apart
when subjected to seasonal temperature changes, earthquakes, floods,
and other natural and man-made assaults on their integrity.”
The potential for danger from escaping natural gas requires that
all joints are sound. To describe and test products for joining
plastic gas pipe, two ASTM specifications approved in 1999 complete
a set of four critical standards on gas pipe fittings:
- F 1948, Standard Specification for Metallic Mechanical Fittings
for Use on Outside Diameter Controlled Thermoplastic Gas Distribution
Pipe and Tubing;
- F 1973, Standard Specification for Factory Assembled Anodeless
Risers and Transition Fittings in Polyethylene (PE) Fuel Gas Distribution
Systems;
- F 1924, Standard Specification for Plastic Mechanical Fittings
for Use on Outside Diameter Controlled Polyethylene Gas Distribution
Pipe and Tubing; and
- F 1588, Standard Test Method for Constant Tensile Load Joint Test
(CTLJT).
Henrich said the four standards will serve as uniform communication
tools between gas pipe fittings manufacturers, users, and state
and federal regulatory authorities. Use of these standards will
enable utilities to evaluate new and existing products, and guide
manufacturers to improve existing products and exploit new materials
and technologies while improving performance, containing costs,
and maintaining safety.
The standards were developed by task groups of Subcommittee F17.60
on Gas in Committee F-17 on Plastic Piping Systems, who represent
gas utility companies, fitting and pipe manufacturers, independent
test laboratories and consultants, trade groups, and federal and
state regulatory agencies. “For about 13 years,” described Henrich,
“more than 50 people worked on numerous drafts of each standard
before the final consensus versions were approved. Performance
requirements and, whenever appropriate, the test procedures have
been standardized in the three fittings standards.”
Standard F 1948, Specification for Metallic Mechanical Fittings
for Use on Outside Diameter Controlled Thermoplastic Gas Distribution
Pipe and Tubing, covers requirements and test methods for the
qualification of metallic mechanical fittings for use with outside
diameter-controlled thermoplastic gas distribution pipe and tubing
as specified in ASTM D 2513, Specification for Thermoplastic Gas
Pressure Pipe, Tubing and Fittings.
Standard F 1973, Specification for Factory Assembled Anodeless
Risers and Transition Fittings in Polyethylene (PE) Fuel Gas Distribution
Systems, covers requirements and test methods for the qualification
of factory-assembled anodeless risers and transition fittings,
in sizes through NPS 8, for use in polyethylene (PE) gas distribution
systems.
Standard F 1924, Specification for Plastic Mechanical Fittings
for Use on Outside Diameter Controlled Polyethylene Gas Distribution
Pipe and Tubing describes requirements and test methods for the
qualification of plastic-bodied mechanical fittings for use with
outside diameter controlled polyethylene (PE) gas distribu-tion
pipe, nominal 2 pipe size (IPS) and smaller complying with ASTM
D 2513, Specification for Thermoplastic Gas Pressure Pipe, Tubing
and Fittings. In addition, it specifies general requirements of
the material from which these fittings are made.
Standard F 1588, Test Method for Constant Tensile Load Joint Test
(CTLJT) presents the constant tensile load joint test (CTLJT),
designed to demonstrate that a joint in a plastic piping system
is resistant to the effects of long-term creep. The joint is subjected
to internal pressure criteria at a sustained axial tensile load
for a specified period and must meet requirements.
“In my 20 years of ASTM membership, these standards stand out
as fine examples of how all interests work together to reach a
consensus to produce very useful, much needed standards.” ASTM
standards are available through Customer Service (610/ 832-9585;
e-mail: service@astm.org), or the Web site (www.astm. org).
For further technical information, contact Raymond Henrich, 2030
Ordway, Golden Valley, MN 55422 (612/588-5826). Committee
F-17 meets during ASTM Committee Week, Apr. 10-13, in Toronto,
Ontario, Canada. For meeting or membership information, contact
F-17 Staff Manager Pat Picariello, ASTM (610/832-9720). //
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