Most pumps have to be full of liquid before they will pump, but a self priming pump can clear the air from its suction and start on its own. That saves the bother of filling it by hand.
This matters where the liquid sits below the pump or where a pump has to start often. A self priming pump handles those duties without an operator priming it each time.
This guide explains what self priming pumps do, where they help in the plant, and how to keep them reliable.
What Self Priming Pumps Do
An ordinary pump loses its prime if air gets into the suction, and it will not pump until it is filled again. A self priming pump is built to clear that air itself.
It holds a store of liquid that lets it draw the air out of the suction line and pull the liquid up. Once the liquid arrives, it pumps as normal.
That ability to start on its own is what sets these pumps apart and makes them handy for awkward duties.
Where They Help in the Plant
Self priming pumps suit places where the liquid sits below the pump, such as sumps and pits, where an ordinary pump would struggle to draw up.
They also help where a pump starts and stops often, because they do not need priming each time. That saves labour and avoids a dry start.
By starting cleanly on their own, they keep these awkward drainage and transfer duties moving.
Signs a Self Priming Pump Needs Attention
A self priming pump in trouble shows up at the start.
- The pump slow to prime or failing to prime
- Air leaking into the suction line
- The store of priming liquid running low
- Flow falling once running
- Leaks at the seal or joints
What Makes a Good Self Priming Pump?
A self priming pump is judged by quick, sure priming and reliable running.
Quick and Sure Priming
The pump must clear the air and pull the liquid up quickly and every time. Sure priming is the whole point of the pump.
A Tight Suction Line
Air leaking into the suction defeats priming, so tight joints matter. A sound suction line keeps the pump priming cleanly.
Keeping Self Priming Pumps Running
Routine attention keeps self priming pumps starting cleanly.
- Keep the suction line tight against air leaks
- Keep the store of priming liquid topped up
- Watch that the pump primes quickly at each start
- Maintain the seal, bearings, and drive
Common Questions About Self Priming Pumps
It means the pump can clear the air from its suction and start pumping on its own, without being filled with liquid by hand first.
Where the liquid sits below the pump, such as sumps and pits, and where a pump starts and stops often and cannot be primed by hand each time.
Air leaking into the suction line or a low store of priming liquid are the usual causes. Sealing the suction and topping up the liquid restore priming.
Keeping the suction line tight, the priming liquid topped up, and the seal and drive maintained keeps the pump priming and running cleanly.
Start Cleanly, Every Time
A self priming pump clears its own air and starts without being filled by hand, which suits sumps, pits, and duties that stop and start often. Sure priming and a tight suction keep it working.
If a drainage or sump duty keeps losing its prime, a self priming pump is worth considering. Explore our pumps and plant equipment for the right fit.
See our range of pumps and handle sump and transfer duties that need clean, sure priming.
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