Vacuum priming systems are used in several applications, but predominately to prime centrifugal pumps when installed without a flooded suction. The vacuum priming system floods the suction piping so that the pump can be started. Automatic systems maintain the prime between pump operation so that any pump connected to the vacuum priming system can be started without delay. Siphons are another huge application for vacuum priming systems. Whether siphoning from a river, reservoir, pond or ocean a siphon priming system is designed to prime the siphon to initiate flow, and maintain the siphon so flow is not diminished or interrupted with loss of prime.