1. (1) Screw joints must be made tight with pipe-joint compound that is insoluble in liquefied petroleum gas.
2. (2) Pipe-joint compound must be approved for the type of gas used. The pipe-joint compound must be applied to the male threads only.

[Statutory Authority: RCW 43.22.340, [43.22.]355, [43.22.]360, [43.22.]432, [43.22.]440 and [43.22.]480. WSR 96-21-146, § 296-150C-1390, filed 10/23/96, effective 11/25/96.]