Column 3 Gas appliances and plastics

From around 1955, thermosetting plastic was used to make buttons and covers of gas appliances. Polyacetal is used to make gas sockets.
Polyethylene is used in making gas pipes laid underground, which are principle to the supply of gas. They used to be green, but now yellow, the international standard, is used.
Plastics are resistant to corrosion, vibration, and expansion and contraction, which greatly minimizes the possibility of gas leaks. And plastics connections can be heat sealed, which greatly facilitates maintenance. So plastics are materials that are indispensable from the standpoint of disaster prevention.

Gas pipes

Rubber socket