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Unread 16-02-2014, 07:30
kmusa kmusa is offline
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AKA: Karlis Musa
FRC #0639 (Code Red Robotics)
Team Role: Mentor
 
Join Date: Jan 2009
Rookie Year: 2006
Location: Ithaca, NY
Posts: 117
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Re: Calibration of secondary relief valve

Quote:
Originally Posted by Al Skierkiewicz View Post
Karlis,
This is an area of particular confusion. There is a difference between max operating pressure and recommended operating pressure. This is a case where manufacturers have maybe listened too hard to their marketing department. If the manufacture states a recommended operating pressure of 30-125 psi, that is not the max operating pressure. Your solenoids may meet FRC rules without the need for the secondary relief valve.
True. Unfortunately, the manufacturers often use operating, maximum, and/or proof pressures, and FIRST wants max working pressure (and (from Q&A) specifically excludes proof pressure as a substitute.)

In our case, STC's 4V110-1/8, with "operating pressure" of 21 to 115 PSI, and "maximum pressure" of 180 PSI (@75 Deg F).

Setting the relief valve to 100 PSI is probably the best approach (since the regulator should release anything above 60 (or whatever the current set point is.))

On the other hand, having the low pressure side at 100 PSI for the test can be a little exciting, when making sure that nothing is inadvertently activated, and the robot is disabled once the compressor cuts out. Next time, we'll just plug the output of the regulator.

Did discover some tired fittings in the process.

-Karlis
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