Direction of compressor pump sheave rotation…

I was criticized recently by a visitor to my about-air-compressors.com information site. An owner of a small DIY type air compressor asked me about the rotation of the pump sheave, and whether or not I thought that the direction of travel was important, and how would they find out the answer?

I responded to that visitor that as far as I was concerned, since a reciprocating compressor pump piston only goes up and down, whether the crank was rotating one way or the other would make no difference to that  compressor pump  operation.

My, another visitor strongly disagreed, pointing out that there were timing issues for valves, for this and for that, and direction of rotation very much made a difference.

I stand my ground.

Yes, where there are ancillary functions dependent on the rotation of the crank… water pumps, oil pumps, fuel pumps, ignition sequences etc, sure rotation matters.

A DIY $200 air compressor doesn’t have all of that stuff! It has intake and pressure valves made of spring steel, and when the piston cycles up or down (reciprocates) one or the other of the two valves opens and the other closes based on the air being pulled into the cylinder or being pushed out of the cylinder as the piston cycles.

There are no other components that rely on the rotation of the compressor pump crankshaft to operate, and the intake and pressure valves couldn’t care less what the direction of the crank is, as long as the piston moves up and down!

Having said that, another visitor says that sometimes, if you look closely at the pump pulley, you might see a small arrow on the side of the sheave to show direction of travel. Or, check with the compressor manufacturer to be absolutely sure, if you can find them!

This is my .02 cents worth. Other opinions are welcome.

Electric compressor motor problems….

When I began building my compressed air information website About-Air-Compressors.com, over six years ago, I had no idea that it would morph into a website that gets visited thousands of times each day. This is good.

However, many folks take me to be the ultimate source for information to do with their air compressors, and send in a broad range of questions to the ASK page, about almost every conceivable thing about air compressors, and many of those subjects, believe me, I am no authority on.

One of the areas that I get a lot of questions on is electric motors for air compressors. I am not an electrician. I do not rebuild motors. Though I understand how they work in general, the specifics elude me, as they would elude anyone not in the field.

So, and sorry to take so long to get to this, I’ve established a forum on the website specifically for compressor electric motor problems. I can’t answer all the questions. If you are into electric motors, and would like both to help, and perhaps find a customer for your motor repair shop, why not visit:  Compressor Motor Problems?

A question about “Load Genies”

Recently, a visitor to www.about-air-compressors.com asked about the use of a Load Genie to help reduce the startup load on their air compressor electric motor. Hmmm! That was a new one on me, so I did a bit of research, and went right to the source, the manufacturer.

The photo used is from the Milton Industries website.

I asked, “Recently I have had requests from visitors about using your Load Genie product. I have scoured your website and can find general info. My visitors would like in-depth information on this product, in particular, when to use it, does it replace existing pressure switches, unloader valves and checkvalves, how is the Load Genie is installed, and what can you remove from the compressor circuit if you install a Load Genie?  I would be very happy to post any information you might be able toprovide, and give attribution and a link back to your site, if you can provide me info.”

I heard back from Steven Goldish, the Director of Marketing for Milton Industries, the manufacturer of the Load Genie. He provided this information, ” A Load Genie replaces the tank check valve and unloader valve only.  It is for use when a pressure switch does not have an unloader valve.  All compressors should have an unloader valve on them.  This prolongs the life of the compressor.  The load Genie should be installed in place of the tank check valve.”

The catalog page says… “A load genie is a combination un-loader and check valve. Unloads discharge manifold in either vertical or horizontal position of any compressor when compressor cycles and flow stops. Effi cient, quiet, economical and eliminates tubing/fi ttings of conventional pressure switch un-loader.”

Steven’s response does suggest that you do not need a Load Genie if your pressure switch already operates an unloader valve, and, adding a Load Genie to a compressor that has a functioning unloader valve is a waste of time and money.

If you are puzzled about what a Load Genie is, here is the their website: www.miltonindustries.com . If you go to their catalog page, the Load Genie is on page 67.