Pipe threads are a lot like suction strainers in that they have no place in a modern, properly designed hydraulic system. HOWEVER, pipe threads are a legacy item, and as such, are still a feature of many (too many) hydraulic systems still in operation today. So every hydraulics user needs to know about them.
National Pipe Tapered (NPT – U.S.) … Read more
The term pilot ratio refers to the ratio of two, discrete areas of a piston, spool or poppet on which opposing pressures act. The pilot area, on which pilot-pressure acts, is always the larger of the two areas. Working or system pressure acts on the smaller, opposing area. This means a relatively small pilot pressure can overcome a much larger … Read more
While 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