A Diaphragm Pump is a type of Positive Displacement Pump. that uses a set of two internal diaphragms, either made from PTFE or rubber, that work simultaneously to create pressure to push fluid through the pump. The diaphragms operate the internal valves on the side of the pump which help to control flow direction and fluid quantity being transferred to the discharge outlet. DEFU Diaphragm Pumps are able to self-prime up to 5m from a dry suction pipe or 8m from a wetted pipe. We have Plastic diaphragm pumps,Stainless steel diaphragm pumps and Aluminum diaphragm pumps.

Diaphragm Pumps are one of the most common and effective pumps on the market today, offering the ability to pump high volumes at low pressures, and robustness to withstand a variety of applications. 

Today i want to share how to change the diaphragm.

To service the diaphragms first shut off the suction, then shut off the discharge lines to the pump. Shut off the compressed air supply, bleed the pressure from the pump, and disconnect the air supply line from the pump. Drain any remaining liquid from the pump.

Step 1: Removing the manifold Using a wrench or socket, remove the 16capscrews and hex nuts that fasten the manifolds to the liquid chamber.

Step 2: Removing the liquid chamber Using a wrench or socket, remove the 16capscrews and hex nuts that fasten the liquid chamber and air chamber. Then remove the liquid chamber.

Step 3: Removing the diaphragm assemblies.Using a wrench or six pointed socket tore move the diaphragm assemblies (outer plate, diaphragm and inner plate) from the diaphragm rod.

Using a wrench or socket to remove the out diaphragm plate.Inspect the diaphragm for cuts，punctures，abrasive wear or chemical attack. Replace the diaphragms if necessary.

Step 4: Installing the diaphragm assemblies to the pump.Push the threaded stud of the diaphragm plate through the center hole of the diaphragm. Push the inner plate onto the stud.

Thread the stud of the one diaphragm assembly into the tapped hole at the end of the diaphragm rod until the inner plate is flush to the end of the rod. insert rod into pump.

Make sure the edge of the diaphragm inset the groove of air chamber.

Fasten the liquid chamber to the pump using the cap screws and hex nuts.

On the opposite of the pump. pull the diaphragm rod out as far as possible.Thread the stud of the remaining diaphragm assembly into the tapped hole at the end of the diaphragm rod as far as possible.

Fasten the remaining liquid chamber to the pump, using the caps crews and hex nuts.

Step 5: Re-install the manifolds to the pump, using the capscrews, hex nuts and flat washers.

The pump is now ready to be re-installed connected and returned to operation.

OVERLAY DIAPHRAGM SERVICING The overlay Teflon diaphragm is designed to fit over the exterior of the Santoprene diaphragm.

Follow the same procedures described for the standard diaphragm for removal and installation.

Any needs, pls feel free to contact with Cindy (sales9@defupump.com) for more information. we are air driven diaphragm pump Manufacturers in China.