Excessive pump vibration- On Stokes 412 and 912 models, vibration arises because the pump internals are used in an "as cast" condition without any kind of attempt at weight equalization.  There can be a 5 to10 pound variation in eccentrics and piston-slides.  This can result in a rough running pump if you have an unfavorable stack up of internal component weights.   The solution is doing dynamic balancing to reduce shaking forces. On all our 412 & 912 rebuilds, we perform a dynamic balance  to minimize horizontal primary shake. 

Why Filter?----Filters capture a large volume of harmful particles and materials in vacuum pump oil which in turn extends pump life and lowers maintenance costs. Many vacuum processes such as sintering and coating can give off particles, liquids and gases that end up in the vacuum pumps. Inlet traps can help but often they are not enough. Sludge can form in the pump oil whether or not particles react chemically with the oil. Acids can also form from process gases and cause accelerated pump wear. So filtration is one way to combat many problems.

Some pumps incorporate a filter, but most have none. So, external filtration is one way to reduce the frequency of oil changes and address the problem. MHV offer a single-element filter system and a triple-element filter system (shown below) to meet most applications.

The elements are rated to remove 75% of particulates above 10 microns with a weighted average efficiency rating of 99.56% and a capacity rating of 269.2 grams.