Almost Had A Gloat

[Howard Rosenberg]

I just bought the P-C C3151 compressor.

Waaaay quieter (less noisy) than my 150 PSI P-C pancake.
Obviously way more oomph.

Broke it in as per the instructions.

But....

it's a 150 PSI compressor - when I filled the tank to build pressure, the gauge would read to a MAXIMUM of 140 - somewhere around 135.

How big an issue is this?

This thing is HEAVY - I'm reluctant to put it into the car to drive it back to exchange it if I don't absolutely have to.

Thanks.
Howard

[Mac McAtee]

Gage out of calibration? Can you take the gage off, open it up and adjust the hand to point to dead "0". If at the 0 mark it is leaning against a peg it could be the problem. Some gages have a little screw that you can turn to zero them, cheaper gages don't. Also if you have another gage that you can put on there temporarily you could compare readings.

[Jim Becker]

Pick up a mini-regulator that has a guage on it. Not only will it help you "check" the one on the compressor, but it's a handy thing to have around the shop anyway, especially if your compressor is in a closet.

[Ted Shrader]

Howard -

Don't know if you will be able to calibrate the gauge that came with it. Mac's idea about changing gauges for comparison is a good one. Then put the original back on and pay it no further mind - unless the pressure goes beyond the 140 indicated.

When the compressor comes on, nobody runs over to it and watches the pressure come up. They just rely on the automatic pressure switch to cut it off at the top end.

If you are adjusting pressure for a specific task - spraying or nail set depth (on some guns), you don't use the gauge much, just adjust the regulator until the pressure is right at the tool.

Sounds like a gloat to me!

Ted

[Mac McAtee]

One other thing. That tank should have a relief valve, safety relief. Look at it, it should be marked as to what pressure it relieves. This keeps a runaway compressor from blowing up the tank, your shop and yourself. It lets air start leaking out at what ever pressure it is set at. It may be discussed in the manual that should have come with the unit.

If it is marked 150 PSI then you don't want to pump up 150 lbs. of pressure in your tank. You want it just below that so it doesn't open and let air out.

If the compressor is shutting off when it gets to the 140 lb. area then your pressure regulator/differential switch is set to shut it off at that pressure. That also should have an adjustment on it that you can change. Look in your manual or look at the cover on the pressure switch and somewhere it will tell you what screw to turn and which way to turn it to increase or decrease pressure.

But you don't want to raise the off contact up to or above the relief valve pressure.