The Pageboy SFD15 self-priming diaphragm pump is ideally suited to pumping aggressive or corrosive liquids, such as solvents, strong acids or alkalis. Available from liquids handling specialists Pump Engineering, this pocket sized, air-operated pump has only 3 moving parts and low air consumption.

A unique feature of the SFD pump is the "Stress-Free Diaphragm" which plays an important part in the pumps' reliability and long-life Unlike other diaphragm pumps, which use a rod to return the diaphragm, the SFD15 uses a venturi to create a vacuum behind the diaphragm. At the end of its suction stroke, a control rod attached to the diaphragm blocks the outlet on the venturi, diverting air onto the back of the diaphragm creating the discharge stroke. As it is used simply to separate the air from liquid, it is not subject to the same stresses as a conventional diaphragm, where the return stroke is a mechanical process.

The pump will stop automatically against a closed valve maintaining a delivery line pressure equal to the air supply pressure and starts automatically when the delivery line pressure falls, such as when a valve is opened.

The SFD 15 pump is designed for vertical upward flow and can be mounted by the extended tie rods supplied. It has a maximum output of 3 lit / min and maximum pressure of 6 bar. As standard, the air supply required is 80 - 100 psi and air consumption is approximately 0.5 cfm. A special version can be supplied for lower air pressures.

A choice of body materials includes polypropylene, PTFE, stainless steel or aluminium, the diaphragm is made from PTFE, with seals to suit application.