Section 680IAC2-5-10. Pressure reducing valves; relief or safety valves; hand-controlled bypasses

   (a) Where pressure reducing valves are used, one (1) or more relief or safety valves shall be provided on the low pressure side of the reducing valve in case the boilers or unfired pressure vessels on the low pressure side do not meet the requirements for the full initial pressure. The combined discharge capacity of the relief or safety valves shall be such that the pressure rating of the boilers or unfired pressure vessels shall not be exceeded in case the reducing valve sticks open. The relief or safety valves shall be located adjoining to or as close as possible to the reducing valves. Protection shall be provided to prevent injury or damage caused by the escaping fluid from the discharge of the relief or safety valves if vented to the atmosphere.

  (b) The use of hand-controlled bypasses around reducing valves is permissible. The bypass, if used around a reducing valve, shall not be greater in capacity than the reducing valve unless the boilers or unfired pressure vessels downstream therefrom are adequately protected by relief or safety valves or meet the requirements of the high pressure system.

  (c) It is mandatory that a pressure gage be installed on the low pressure side of such a reducing valve as set forth in subsection (b). (Boiler and Pressure Vessel Rules Board; 680 IAC 2-5-10; filed Jan 5, 1996, 10:15 a.m.: 19 IR 1125; readopted filed Jul 9, 2001, 1:33 p.m.: 24 IR 3822; readopted filed Sep 21, 2007, 9:16 a.m.: 20071010-IR-680070389RFA; readopted filed Oct 19, 2007, 1:08 p.m.: 20071114-IR-680070389RFA; readopted filed Sep 5, 2013, 10:09 a.m.: 20131009-IR-680130182RFA)