Why Air is One of the ‘Big 4’ Contaminants of Hydraulic Oil

cavitation erosion on valve plateAir is both a normal ingredient, and a contaminant, of hydraulic oil. It’s a normal ingredient because hydraulic fluid typically contains between 6 and 12 percent by volume of dissolved air. There’s no avoiding this. And provided this dissolved air stays dissolved, it poses no problem to the hydraulic system or the fluid itself.

But if this dissolved air comes … Read more

The Official Word On Hydraulic Pump Suction Strainers

suctionstrainerclogged-resizeWhile doing some fact checking for a consulting job, I had cause to review Australian Standard AS 2671; Hydraulic Fluid Power-General Requirements for Systems. This Australian Standard is basically the International Standard, ISO 4413 with some amendments based on the local advisory committee’s input.

One of these amendments has to do with pump suction strainers. Section 8.3.3 of ISO 4413:2010, … Read more

How Far Can a Hydraulic Pump Be From the Hydraulic Tank?

Not an ideal pump mounting positionOne of our members described the hydraulic layout of a rear-mounted knuckle crane on a truck, which was giving trouble, as follows:

“The pump is a bent axis Muncie pump 20 GPM, 4300 PSI. The pressure line is 3/4″ hose and steel tube. The pump intake line is a 2″ suction hose from the tank located on the crane base Read more