Self-priming Varisco pump: How it works

The self-priming centrifugal pumps of the series J and ST-R Varisco are designed and manufactured to guarantee high performance and ease of use in multiple industrial, purification and waste fluid management sectors in general.
Self-priming: the operating principle of the J and ST-R series
The air (yellow flow) is drawn into the pump by the vacuum created by the moving impeller, and it emulsifies with the liquid (blue) in the pump body. The air-liquid emulsion is forced into the priming chamber where the lighter air separates and comes out from the delivery pipe; the heavier liquid falls back and recirculates. Once all the air is expelled from the suction duct, the pump is activated and runs just like a regular centrifugal pump. The pump can also run with an airliquid mixture. The non-return valve has a dual function: it prevents the suction pipe from emptying when the pump is not running; if the suction pipe is accidentally emptied, it keeps sufficient liquid in the pump body for priming. The delivery pipe must be free to release the air deriving from the suction.