Our team has just discovered this morning that the Norgren “125” psi relief valve as supplied in the KoP was NOT calibrated to 125 psi.
We took it up to 160psi and it did not release.
Rule <R77> states in bold letters that Teams are not allowed to adjust the 125-psi relief valve.
The “Pneumatics Manual” at the USFIRST website says nothing about adjusting this valve.
Are other teams aware of this potential safety issue?
~
A couple years ago we got one that was loose (the locknut was not tight, so the adjusting nut could turn freely). We adjusted it to open at 125 psi, and should probably be suitably chastised.
It is a problem if you have safety devices that are adjustable, and are not properly adjusted, and you are not allowed to adjust them.
Quick, contact FIRST and get a replacement sent to your team!
or see if you can use one from a previous year?
Our team has never received one in the KOP that was properly adjusted. Request a new one, however dumb that may sound.
The 16-004-011 Relief Valve in the KOP is a generic relief that is designed to be field set from 75 to 150 psi.
The item can be ordered from the factory pre-calibrated at any pressure you want. Usually but not always it arrives in good order in the KOP set at 125.
In the past 5 years we have received 2 not calibrated correctly. I’m not talking NIST traceable calibration. I’m talking about using the KOP pressure gauges as reference.
We always confirm the relief at 125 gauge pressure as we test out our system. This year we have built two system in parallel (one is a training system).
One system checked out. The second system went to 135 before we ended the test. We will have to calibrate the relief.
I don’t agree with the FIRST policy of “do not adjust”. There should be a two step procedure instead.
Part 1 is confirming the relief setting which includes shutdown and purge at 135 if the test fails. Not going clear to 160.
Part 2 is correcting the relief setting if necessary.
IMHO !
We have the same problem with ours - does not relieve at 125 (I think we have taken it to 160 as well); we replaced it with last year’s valve (still fresh in the bag) and had the same problem. The gage seems to be OK - it tracks with the one downstream of the regulator up to 60.
I don’t see anything on the Q&A so I’m going to ask if it’s OK to adjust the valve if we discover it is not set at 125 psi (since R77 doesn’t allow it).
We had this problem and changed out the valve and it works now, I dont know how to fix the other one. It seems like some one should tell first about this little problem.
Looks like this has been addressed in update 11:
<R77> The relief valve must be attached directly to the compressor. If the relief valve is already set to 125psi, teams are not allowed to adjust it. If the relief valve is not set to 125psi, teams are required to adjust to release air at 125psi. The valve may or may not have been calibrated prior to being supplied to teams.
Jim Forbes mad a good post a few years ago on how to adjust the PRV. You can find it here.
Perhaps someone can post pictures and step-by-step instructions for the technically challenged out there so they can do this successfully.
Any volunteers?