Variable Displacement Pumps

VDS vacuum pumps can provide over 20" Hg (68 kPa) and their straight through, non-clog design is ideal for very dusty and dirty applications such as bag filling or handling ceramics or masonry products. The square body and two mounting holes makes the VDS pump easy to attach to any flat surface. A straight-thru silencer will not accumulate debris and will pass it out with the exhaust air. For less critical applications where cost is more of an issue, a conventional AA silencer may be used.


Loosen the jam nut and turn the diffuser nozzle clockwise, by hand, until it contacts the inlet nozzle. With the work piece against the vacuum cup or holding fixture, supply regulated, compressed air to the side air supply port and gradually rotate the diffuser nozzle to adjust the annular gap between the two nozzles until the desired vacuum level or vacuum flow is achieved. To minimize air consumption, use the lowest pressure air spuply that will yield the desired results. Turning the diffuser too far open will cause a sudden decrease in performance and this point will vary depending on the operating air pressure.

Ingested debris passes directly from end to end through the pump bore without any turns and without passing through the annular venturi created by the inlet and diffuser nozzles so there is no opportunity for clogging as long as the pump bore is large enough to pss the largest debris particle. As the pump bore size is increased, it can also generate more vacuum flow to overcome porosity and leakage.