Priming systems for pumps

A priming system for a liquid pump having an inlet side and an outlet side, said system comprising:

• collecting means on the inlet side of the liquid pump having a contents of liquid and vapor, said collecting means accumulating the vapor from the liquid so that only liquid may be supplied to the liquid pump;
• priming pump means for extracting said contents from said collecting means;
• duct means extending from said collecting means to said priming pump means and through which said contents of said collecting means is extracted;
• separating means for receiving said contents from said priming pump and separating the liquid of the same from the vapor;
• further duct means extending from said separating means to said liquid pump for permitting liquid from said separating means to return to the liquid pump;
• and
• said separating means comprising a container having a first means for returning liquid to said further duct means and a second means for discharing vapor from said container, said first means including a valve initially open to permit return of liquid to the liquid pump and said second means including a second valve initially open to permit discharge of vapor from said container, said second valve being closed when liquid in said container reaches a predetermined level and said first valve being simultaneously operable to restrict the rate of flow of liquid to said further duct means when said liquid in said container reaches the predetermined level.