WAC 296-104-330
Installation -- What are the relief or
safety valve requirements when pressure reducing valves are
used? (1) Where pressure reducing valves are used, one or
more relief or safety valve(s) and pressure gauge(s) shall be
provided on the low pressure side of the reducing valve. The
relief or safety valve(s) shall be located as close as
possible to the reducing valve. The combined discharge
capacity of the relief valves shall be such that the pressure
rating of the lower pressure piping or equipment shall not be
exceeded in case the reducing valve sticks open. Discharge
lines shall comply with WAC 296-104-320.
(2) The use of hand-controlled bypasses around reducing
valves is permissible. The bypass shall not be greater in
capacity than the reducing valve unless the piping or
equipment is adequately protected by a relief valve(s) or
meets the requirements of the high pressure system.
[Statutory Authority: RCW 70.79.030, 70.79.040, 70.79.150,
70.79.290, 70.79.330, and 70.79.350. 08-12-015, §
296-104-330, filed 5/27/08, effective 6/30/08. Statutory
Authority: RCW 70.79.030 and 70.79.040. 97-20-109, §
296-104-330, filed 9/30/97, effective 10/31/97; Part V, § 7,
filed 3/23/60.]