Self-Priming Peripheral Pump, BP-10-UTH, Stainless Steel, IP44, 1 HP, 6 Bar, Green

If a pump is located beneath the level of the liquid to be pumped, gravity and air pressure ensure that it is constantly filled with the liquid and there can be no ingress of air into the pump or suction line. In many applications, a pump has to be placed above the level of the liquid, for example, when emptying an underground storage tank. At start-up, there will be air in the suction line and before the pump can discharge the liquid, this air must be evacuated or displaced. Pumps are optimised to move a particular liquid; evacuating a gas is a very different challenge. Various methods can be used to get around this problem. A secondary pump can be used to evacuate the suction line. A non-return (foot) valve or evacuation tank can be used to stop fluid draining from the suction line when the pump is stopped. However, these solutions all involve extra equipment, piping and processes. Ideally, for these applications, a pump is required that can evacuate air from the suction side at startup before commencing its normal pumping mode. Such a pump is considered to be self-priming.