Help Identifying Old Belt-Drive Compressor

[uberschall]

Howdy.

Ages ago, my dad bought a lot of equipment from his HS shop teacher, including (but not at all limited to) a table saw, drill press, pedestal grinder, and sander - and was given this old compressor as part of the deal.

It's never been running in the 3 decades I've been part of the picture, and I'm going to guess it's got another 20-30 years on top of that.

It's always been in a garage. I have a box full of bits - pressure switch, regulator, some hoses, etc. - but nothing with a manufacturer's logo or name. The motor isn't original - the bolt pattern on the base doesn't line up with the mount anyway.

The paint is definitely not original. I replaced the wheels, as the solid tires had serious flat spots.

I would really like to get it running before he retires, and hoped someone might be able to help ID it from photos. I can take more if needed.

Thanks in advance!

 

[Carla]

It looks like an old refrigeration compressor to me.

A bit of vague memory on the subject, from quite a few years ago, was that old-style refrigeration compressors would turn up in the scrap yards as small stores, etc., modernised their cold storage systems.

Tho they were often available for very cheaply, they were quite inefficient as air compressors. As a generality, these compressors were high quality, and very strongly built, and would compress air, but at a very low 'volume' in 'CFM' terms, owing to the small valving and ports.

In short, if you mean to keep it as a decorative widget, fine, but it won't produce a useful volume of air.

There were several makers (DeVilbiss, Quincy, Kellogg, Curtis, etc.) who produced high quality single-cylinder compressor pumps which were suitable for small portable compressor systems like that one.

There were some hardware store chains which sold them under 'house brands' as well.

These were meant as 'home hobby shop' units, which would supply a reasonable amount of 100psi air for tire inflation, spray-painting with a small-orifice paint gun, etc.

You should be able to find a suitable small pump by putting in a 'wanted' advert here, or on your local Craig's list. The pumps are surprisingly common, as the thin cheap tanks on which some were mounted would perish from rust, and the motors and pumps would be saved.

cheers

Carla

 

[uberschall]

Very well said, thanks for the input Carla!

A quick search revealed that the topic can be argued either way, but I'd tend to agree that it looks like a condensing unit pump due to the lack of provision for cooling (non-fan pulley, shallow fins, doesn't look like a vented case) and probably won't be useful.

I should mention that the tank is BIG - haven't done the math but looks to be around 45 gallons. Is there a general rule for sizing a pump for that volume?

If anyone can chime in with an ID for the refrigeration compressor, that would still be neat.

Cheers!

 

[Carla]

Very well said, thanks for the input Carla!

A quick search revealed that the topic can be argued either way, but I'd tend to agree that it looks like a condensing unit pump due to the lack of provision for cooling (non-fan pulley, shallow fins, doesn't look like a vented case) and probably won't be useful.

I should mention that the tank is BIG - haven't done the math but looks to be around 45 gallons. Is there a general rule for sizing a pump for that volume?

If anyone can chime in with an ID for the refrigeration compressor, that would still be neat.

Cheers!

The very first thing to do is to test that tank.......the little single cylinder, single stage compressors are meant for 100psi air service, which is quite adequate for hobby use.

Any older air tank is an 'unknown' until tested. It may be good, or it may have line-rusted on the inside, and be ready to 'blow'.

Arrange to borrow some space, and air, and bring your tank, in a safe (away from humans) location, to at least 135, preferably 150 lbs pressure, and hold it there for a while, preferably over-night. If it holds 150psi for some hours, it will be safe at 100psi. If it ruptures at 150, it was weakened, and would have eventually failed at 100.....and even a small tank at 100psi can badly injure any nearby humans should it 'blow' violently.

A violent tank rupture is uncommon, more often they will just have pin-hole leaks at the bottom, but one mustn't take any chances. You can read the stories of air tank 'explosions' on the internet, with a 'search'.....there have, albeit very rarely, been fatalities, with larger tanks, and serious injury with small ones.

If the tank checks out as 'good', then ask about a pump.

cheers

Carla

 

[G_P]

There might be some identifying marks under the paint. Those older pumps almost always had some cast in numbers or a name.

 

[uberschall]

Thanks again, Carla. A friend has a huge compressor in his shop that should be able to supply 150+ psi to test the tank, along with enough hose to set it up in the parking lot.

Here are pictures of the numbers cast into the tank and head, respectively:

It certainly looks like a twin cylinder based on the bolt pattern on the head.

I may hit the pump with some Aircraft to see if there's anything hidden under there.

Edit: sorry about the rogue finger in there, wasn't pointing at anything!

 

[91bronc300]

Here's a video I watched just the other day because I've got my own compressor I need to refurb. This guy machines a fitting to connect his pressure washer to this compressor tank and then fills the tank completely with water and uses the washer to pressurize it to double the rated pressure. He then turns the tank into a big rock tumbler by rigging it with a pipe threader machine to clean the inside and then sloshes a bunch of paint around the inside. The guy is long winded but it's a neat video.

 

[uberschall]

Cool video! My tank doesn't have conveniently placed bungs on both end caps, or I'd do something similar to clean it.

Hopefully my local radiator guy knows a place that can boil it out.