Sometimes called Fire Pumps, these models are used to transfer water long distances or to deliver water at high pressure.  Among their many uses are firefighting, rescue work, jetting in piles, washing boats, cleaning pools, providing irrigation and testing water mains.  The exhaust priming system provides quicker priming, and the built-in flapper valve helps to hold the prime when restarting the pump.  All three models include a low oil protection system to help guard the engine against damage from operating with insufficient oil.