www.saVRee.com Diaphragm Pumps pg. 5
Good to know – the term ‘self-priming’ means that a pump has the ability to pump air.
3D Model Annotations
Non-return Valve
Non-return valves allow flow in only one direction. As the diaphragm moves, the
pressure created within the casing will either lift the ball off its seat and allow flow, or, press
the ball against its seat and stop flow. The effect the diaphragm has upon each valve depends
upon the orientation of the non-return valve (the upper non-return valve operates in the
reverse direction to the lower non-return valve).
Swing Check Non-return Valve
Suction
Fluid enters the pump through this connection. Diaphragm pumps are positive displacement
pumps; thus they can pump gas, liquid or vapour.
Discharge
Fluid is discharged from the pump through this connection.
Diaphragm Membrane
The diaphragm is actuated via a pneumatic piston. When pneumatic pressure is applied to
one side of the piston, the diaphragm changes to a concave shape. When pneumatic
pressure is applied to the other side of the piston, the diaphragm changes to a convex shape.
As the diaphragm changes shape, a positive (convex) or negative (concave) pressure is
created between the two non-return valves; fluid is sucked or discharged from the pump