By Josh Cosford, CFPHS
The Fluid Power House (Cambridge) Inc.
|Josh Cosford, CFPHS, The Fluid Power House (Cambridge) Inc. |
Last month, I wrote about how an increase in pressure can diminish the size of hydraulic components in your hydraulic accoutrement (that's a real word; look it up). I wouldn't be doing anyone any favors if I didn't follow up with some tips on how to increase pressure safely, and what the downsides are. As important as the rising pressure peak is to the industry, it is not without its issues.
Higher system pressure usually results in more generation of heat. Fluid will work its way past clearances at a higher rate, and any time fluid bypasses at pressure without doing useful work, it creates heat. Therefore, the cooling capacity of the machine will have to be upgraded to handle the job.
An additional by-product of higher pressure is louder noise. Components resonate with more energy, emitting higher sound pressure levels. Design considerations must be made to factor out the increase, with attention to reservoir configuration, plumbing choices and component locations.
There are also potential safety concerns. Although hydraulic fluid is generally considered incompressible, it actually compresses 0.5% per 1000 psi of work pressure. If there is a break or failure in the line, that compressed energy can be released both rapidly and catastrophically. Careful attention must be made to produce a safe system.
Finally, we must consider the effect pressure has on the reliability and maintenance of the machine. A well-maintained, clean and cool system won't see any change in performance or longevity, but with higher pressures come higher susceptibility to damage. Dirt particles can work themselves through orifices, crevices and clearances with more force pushing on them. Lubrication boundary layers can wear thin, causing more friction and wear.
The good news is, that if you follow a strict maintenance regimen — as you always should with any hydraulic machine — you won't see any difference in down time. You should be keeping your fluid clean and cool, anyway. All I can do now, is hope that you received and read last month's article, or these past 340 words are as useless as a screen door on a submarine.
Josh Cosford is a certified fluid power hydraulic specialist with The Fluid Power House (Cambridge) Inc. Contact him at firstname.lastname@example.org or call (519)-624-7109.