Safety Appliances: Each pressure vessel shall be protected by such safety and

Safety Appliances: Each pressure vessel shall be protected by such safety and relief valves and indicating and controlling devices as will insure its safe operation. These valves and devices shall be so constructed, located and installed that they cannot readily be rendered inoperative. The relieving capacity of the safety valves shall be such as to prevent a rise of pressure in the vessel of more than 10 percent above the maximum allowable working pressure, taking into account the effect of static head pressure. Safety valve discharges shall be carried to a safe place.