7-4-19: VALVES AT TANKS AND PUMPS:
   A.   Where tanks are aboveground, there shall be a valve located near the tank in each pipe. In case two (2) or more tanks are cross connected, there shall be a valve near each tank in each cross connection.
   B.   Pumps delivering to or taking supply from aboveground storage tanks shall be provided with valves on both suction and discharge pumps, and in delivering to tanks a check valve to prevent flow of liquid from tank to pump. (1961 Code)