WAC 296-307-41029. Construction and installation of atmospheric vaporizers

Atmospheric vaporizers using heat from the ground or surrounding air must be installed as follows: (1) Buried underground; or (2) Located inside the building near where the pipe enters the building, if the capacity of the unit does not exceed one quart; (3) Vaporizers of less than one quart capacity heated by the ground or surrounding air, may be installed without safety-relief valves if tests show that the assembly is safe.