Pumps delivering to or taking supply from an aboveground tank shall be provided with valves on both suction and discharge side of pumps. When a positive displacement pump is used, a relief valve of sufficient size shall be provided at the discharge side. The discharge of the relief valve shall be piped the same size as the relief valve to the suction size of the pump or return to the supply tank. Integral relief valves may be produced. Flammable liquid discharged by means of a centrifugal pump into an aboveground storage tank, shall be provided with a check valve immediately adjacent to the tank valve.
Any flammable liquid heater or pipe incorporating a heater shall be provided with a relief valve of sufficient size and so arranged to discharge to the supply tank, when any valve, pump, or other device will prevent the release of excessive pressure.
(Prior code § 129.1-41)