- (a) Fittings and appliances on new boilers or new unfired pressure vessels shall comply with the applicable provisions of the ASME Boiler Construction Code, as adopted, or of this subpart.
(b)
- (1) 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 piping or equipment on the low-pressure side does not meet the requirements of the full initial pressure.
- (2) The relief or safety valves shall be located adjoining to or as close as possible to the reducing valve.
- (3) Proper protection shall be provided to prevent injury or damage caused by the escaping steam from the discharge of relief or safety valves if vented to the atmosphere.
- (4) The combined discharge capacity of the relief valves shall be such that the safe working pressure of the lower pressure piping or equipment shall not be exceeded in case the reducing valve sticks in the open position.
(c)
- (1) The use of hand-controlled bypasses around reducing valves is permissible.
- (2) The bypass if used around a reducing valve shall not be greater in capacity than the reducing valve unless the piping or equipment is adequately protected by relief valves or meets the requirements of the high-pressure system.
- (d) The flange dimensions, wall thicknesses, and material of reducing and relief valves shall conform to the requirements specified for valves and fittings for the pressures and temperatures to which they may be subjected.
- (e) It is mandatory that a pressure gauge be installed on the low-pressure side of the reducing valve.