Section 680IAC2-9-7. Safety valves; type permitted; identification; relieving capacity

   (a) Each miniature boiler shall be equipped with a sealed, spring-loaded, pop type safety valve not less than one-half (½) inch pipe size, connected directly to the boiler.

  (b) The safety valve relieving capacity of each boiler shall be such that it will discharge all the steam that can be generated by the boiler without allowing the pressure to rise more than six percent (6%) above the maximum allowable working pressure.

  (c) In those cases where the boiler is supplied with feed water directly from a pressure main or system without the use of a mechanical feeding device, the safety valve shall be set to release at a pressure not in excess of ninety-four percent (94%) of the lowest pressure obtained in the supply main or system feeding the boiler. Return traps shall not be considered mechanical feeding devices. (Boiler and Pressure Vessel Rules Board; 680 IAC 2-9-7; filed Jan 5, 1996, 10:15 a.m.: 19 IR 1133; 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)