NAC512.587. Safety appliances: Generally.

Each pressure vessel must be protected by safety or relief valves and indicating and controlling devices that will ensure its safe operation. These valves and devices must be so constructed, located and installed that the valves and devices cannot be rendered inoperative readily. The relieving capacity of safety valves must be sufficient to prevent a rise of pressure in the vessel of more than 10 percent above the highest pressure to which any device to relieve pressure is set, but in no case more than 6 percent above the maximum allowable working pressure. The opening (set) pressure of the device to relieve pressure must be no greater than the maximum allowable working pressure of the vessel.

     (Added to NAC by Div. of Industrial Relations by R141-98, eff. 1-28-2000)