Plastic Valves in Polyethylene Natural Gas Distribution Networks

In the late 1960's and early 1970ts, polyethylene piping was gaining an early foothold in American
gas distribution piping systems. Early usage centered around service lines as gas companies
experimented with this new type of piping material. During this period there was little need
for plastic valving as companies continued to run welded, coated and wrapped steel distribution
mains.

During the mid-TO'S, the usage of polyethylene pipe for distribution mains started to increase.
Gas Distribution companies started using polyethylene for short main extensions, main replacement
and sub-division work. These systems were small isolated segments of a larger steel and
cast iron distribution systems. Again, the need for polyethylene valving was not yet identified.
The ease of installation, installed cost, and maintenance free characteristics of polyethylene
piping caused its usage to skyrocket during the late 70's and early 80's resulting in extensive
distribution networks of polyethylene. It is currently estimated that 82% of all gas distribution
piping installed each year in North America is polyethylene. Installation for 1984
totaled over 23,000 miles (37,000 Kilometers).

Utilities during this period formulated several schools of thought on how to control this growing
maze of polyethylene distribution main.