Emax 3hp air compressor blowing PRV valve

hi

my 50L 3HP compressor builds up pressure to the recommended 8 bar or beyond. it then blows the prv valve until the pressure drops down to about 5 bar. it then continues building pressure until it blows again and so the cycle goes on. i have tried adjusting the prv a few turns but the same thing happens at more or less pressure, depending on how much i adjust it. its been working fine for the last 3 months i have had it.

thanks

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Bill says...

Do I understand correctly that your PRV is opening at 8 bar (120 PSI), this being the normal cut out pressure of your compressor?

That being the case, my first thought is your PRV valve has failed. Don't monkey with it, replace it.

If, on the other hand, the PRV valve is blowing at, say 140 PSI, when your air compressor is normally shutting off on high pressure cut out at 8 bar, then this points to your pressure switch having failed.

Cheers,

Bill