Diaphragm Pump

Introduction

This is a 3D model of a Diaphragm Pump.

3D Model Annotations

Diaphragm Pump

Diaphragm pumps are a type of positive displacement pump typically used for low pressure, low flow, applications. The pump gets its name from the large diaphragm membrane that it uses to pump fluid.

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).

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 due to the pressure difference created. Diaphragm membranes are typically constructed of thick rubber material.

Pneumatic Valves

Pneumatic valves within the diaphragm casing distribute air to either side of the piston. As air is distributed to each side of the piston, the piston direction changes, and so too does the shape of the diaphragm (convex to concave etc.).

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