WaterWorx instant stop valve has a very high flow rate allowing rapid filling with minimal pressure loss. Designed as a replacement to conventional ballcock valves in water tanks to protect booster pumps, instant stop valve goes instantly from fully open to fully closed. This hydraulically actuated valve is of particular use in pumped systems as it prevents repeated stop/start cycling of pumps when filling tanks or cisterns. The valve passes a high flow rate from the pump immediately. The potential for damage to the pump from overheating is therefore reduced. The efficiency and running costs of the system are reduced as the pump is not running at full power while only delivering a low volume of water through a partially closed valve.