Calibration of pressure relief valve

This may sound silly, but I’m afraid I accidentally messed up the calibration of the pressure relief valve. How should I go about to test it and re-calibrate it if necessary?
Thanks.

<R95> Get a new one. period. No other actions are permitted.

Where? I checked Norgren’s web page, and the valves they sell (exact part number) aren’t pre-calibrated either. It is ok to get a local calibration lab to calibrate it to 120 psi?

last year ours came in the kit “loose”, so we had to adjust it, which is against the rules…but you can do it very easily, although you have to assume the pressure gage is accurate. Loosen the lock nut, turn the adjusting screw as needed, tighten the locknut. see if it works by watching the tank pressure gage, if it goes over the rated pressure of the relief valve, then you need to adjust it more.

Apparently this is all against the rules, so don’t do this. Get ahold of FIRST and get a replacement.

(ain’t politics fun?)