Air Compressor Pressure Gauge

[Glenn F.]

Let me begin with an update on my Quincy air compressor pressure switch question I asked a couple weeks ago. I removed the cover and attempted gently opening the points with my finger tip and the “arm” broke off. I didn’t look any farther. Tomorrow I’m getting a new Square D brand switch in town.

Today’s question is, what do I look for when buying a new gauge? My compressors are in the second story of my shop so I have a gauge on both levels. The one upstairs has always read high. It’s time to replace it.

Thank you,
Glenn F.

 

[rustred]

I like the liquid filled gauges. A 200 lb guage is about right. U want the top psi to register in the 3/4 range of the guages for accuracy.

 

[caterpillar guy]

Depending on the size of the line leaving the compressor tank and the distance the gages are apart it could just be the line drop on the different readings. Switch the gages and see if it switches with the position. If the difference moves with the gage then the gage is the problem. if not then it is the line drop in pressure. Like on your field sprayer if the gage is not reading the boom, but is just in the line to it, the pressure will change from one place to the other.

 

[Destroked 450]

Depending on the size of the line leaving the compressor tank and the distance the gages are apart it could just be the line drop on the different readings. Switch the gages and see if it switches with the position. If the difference moves with the gage then the gage is the problem. if not then it is the line drop in pressure. Like on your field sprayer if the gage is not reading the boom, but is just in the line to it, the pressure will change from one place to the other.

That applies to flowing pressure but static pressure should equalize and be the same at every location

 

[wp6529]

For indoor use most any of the $15 stainless case liquid filled gauges should be just fine, including the ones Harbor Freight sells. You don't need a 6" dial lab grade gauge to monitor a shop compressor.

 

[stevieb49829]

Glenn, I'm sure you know this, but if not, plumb a condensation drop leg below your downstairs gauge, with a valve so you can blow off water, or install an automatic blow off. Gauges work more consistently if the air that goes to them is not liquid. steve