Also known as a Membrane pump that uses a combination of the reciprocating action of a rubber, thermoplastic or EPDM and suitable valves on either side of the body (check valve, butterfly valves, flap valves, or any other form of shut-off valves) to pump a fluid.
When the volume of a chamber of either type of pump is increased, the pressure decreases, and fluid is drawn into the chamber. When the chamber pressure later increases from decreased volume, the fluid previously drawn in is forced out. Finally, the diaphragm moving up once again draws fluid into the chamber, completing the cycle. This action is similar to that of the cylinder in an internal combustion engine. Pumps deliver a hermetic seal between the drive mechanism and the compression chamber, allowing the pump to transfer, compress, and evacuate the medium without a lubricant.
An elastomeric membrain can be used as a versatile dynamic seal that removes many of the limitations found with other sealing methods. They do not leak, offer little friction, and can be constructed for low pressure sensitivity. With the right material consideration, Yamada pumps can seal over a wide range of pressures and temperatures without needing lubrication or maintenance.
