Indiana Administrative Code
Title 675 - FIRE PREVENTION AND BUILDING SAFETY COMMISSION
Article 30 - INDIANA BOILER AND PRESSURE VESSEL RULES
Rule 5 - General Requirements
Section 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 pressure reducing valve in case the boiler or unfired pressure vessel on the low pressure side does not meet the pressure requirements for the high pressure side. 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 pressure reducing valve sticks open. The relief or safety valves shall be located adjacent to or as close as possible to the pressure 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 pressure reducing valves is permissible. Such a bypass shall not be greater in capacity than the pressure reducing valve unless the boiler or unfired pressure vessel downstream therefrom is adequately protected by relief or safety valves or meets the requirements of the high pressure system. A pressure gauge shall be installed on the low pressure side of such a pressure reducing valve.

All pressure relief valves covered by this article must be repaired by an organization in possession of a valid "VR" or "VR/NR" Certificate of Authorization issued by the NBBI.