Self-priming pump

Claim 1

A pump assembly comprising: a barrel adapted to contain a fluid, an inlet to the barrel adapted to allow ingestion of the fluid from a fluid supply into said barrel, a column having a lower end adapted to ingest the fluid from the barrel and an upper end adapted to discharge said fluid, a mixed flow pump interior the column adjacent the lower end of said column adapted to pump a mixture of the fluid and vapor, multiple turbine pumps interior the column downstream of the mixed flow pump, a priming valve including a poppet valve assembly having a first end connected directly to an opening in the column downstream of the multiple turbine pumps and a second end leading into the barrel, said poppet valve assembly adapted to allow passage of the fluid from the column into the barrel when open and to prevent passage of said fluid from the column into said barrel when closed, said poppet valve assembly adapted to be held in the closed position by greater pressure in said column relative to pressure in said barrel, means for biasing the poppet valve assembly to the open position, a discharge conduit connected to the upper end of the column and adapted to receive the fluid discharged therefrom, a discharge check valve located in the discharge conduit and adapted to prevent flow of the fluid through said discharge conduit into the column and permit flow of said fluid out of said column through said discharge conduit, an automatic bypass line having a first end connected to the discharge conduit upstream of the discharge check valve and a second end connected to the barrel, and a bypass check valve interior the automatic bypass line and adapted to prevent flow of the fluid from the discharge conduit to the barrel through the automatic bypass line and adapted to allow flow of air from the barrel to the discharge conduit through the automatic bypass line.