Old Air Compressors - Are They Better?

08 Jul.,2024

 

Old Air Compressors - Are They Better?

The new I-R T 30 compressors have been cheapened up considerably. The castings and some of the machine work on them are coming out of China. I have had the opportunity to compare I-R T-30 series compressors from 20 years ago against recent ones. The quality is definitely way down and things have been lightened up and cheapened up wherever possible. I have a friend with a compressor shop who does a lot of specialized heavy compressor work, so have heard some real warnings about what I-R recip compressors and even their rotary screw compressors have come down to. I-R is building 5-year throwaway compressors compared to qwhat they used to build. Word also is that on some of the smaller T-30 compressor units, I-R is not even building them with an unoader worked off the pressure switch. This is the simplest, cheapest way to make an unloader. Instead, I-R is simply counting on the motor having having enough snot to start the compressor loaded. Word also is they figured out how long the motor would tolerate loaded starts and got it figured well enough so the motors last thru the warranty period.

Quincy offers a few lines of recip compressors. Their original line is still there. These compressors use cast iron cylinders & crankcases, disc valves (as opposed to I-R with reed valves), and the crankcases use automotive type full-pressure lubrication. Quincy cheaped this line just a bit by going to some really crude looking cylinder cooling fins on the castings. Computer modelling showed their engineers that the older design with numerous finer fins was not needed and a few massive fins would carry off the heat.
Quincy uses head unloaders which work the intake valves. Their compressors are designed for heavy service, continuous running. We use them on powerplant governor air supply systems and I have used them on locomotive airbrake systems.

Be forewarned: Quincy's quality took a real nosedive in the past few years. We bought some new compressors from Quincy and found flywheels machined out of true so they had a face runout of almost 1/8", cylinder head air leaks due to sloppy machining, and problems with the oil pump relief valve machining so that a factory new compressor had no crankcase lube pressure. In all cases the local Quincy dealer made good, but it was a PITA to take compressors out of service for repairs. One compressor on a governor air system for our turbines had so many problems due to sloppy machining that Quincy simply shipped in a new compressor. Our powerplant ate the labor on that one. Once we got things straightened out, the newer Quincy compressors have been fine. They are kept live 24/7 only coming down for preventative maintainence & oil changes.

The locomotive airbrake compressors are on a diesle locomotive use din tourist train service. In season, the compressors are run continuously for 12 hours a day, loading/unloading as required. They replaced the original Gardner-Denver compressors. The Gardner-Denvers were iron block, single stage, splash lubed machines. They were put on new with the locomotive in and lasted close to 60 years. Finally, one of them took out a crankshaft, and no parts were available, so I made the move to Quincy. Other than oil and filter changes, the Quincys have run fine for about five seasons.

Quincy makes two other lines of recip compressors, so do not be fooled by the Quincy name into thinking all Quncy compressors are created equal. They make one line which is cast iron construction/splash lubed, and then a line with die cast crankcases and cylinders (iron lners) and reed valves.

Champion is a division of Gardner-Denver. I believe Gardner-Denver is out of the business of building smaller recip compressors. We bought a specialized medical grade breathable air compressor package for the powerplant made by Champion. It was built in Princeton, Illinois. Overall, it seems like a well built unit for the times we liv ein. Meaning: it is lightened and cheapened up any way possible over older compressors. We have had problems with the unloaders on this unit (Control Devices, pilot valve to operated the unloader valve). Otherwise, it seems well built. I have not seen any Champion compressors of conventional (oil filled crankcase) design, so can;t comment further.

Kellog American has been merged and absrobed a few times over. We had older Kellog-American compressors in the fleet garage here at the powerplant. They were an OK compressor, iron construction, splash lubed. They used a centrifugal governor to work a pilot valve for the head unloaders. Problems we had were mainly that the valves were a little light and would give out from time to time. Parts got harder to come by. We replaced the two older Kellogg-American compressors with one big Quincy recip, running nice and slow, about 15 years ago. The last Kellogg-American went for scrap within this past year.

My own 'druthers: If I were buying a large air compressor for a shop, I would hunt down a used Quincy. I would make sure it had the following features: Later model oil pump (Quincy switched from a vane type oil pump to a gear type pump some years back. No parts available for the older vane pumps); Spin on oil filter (again, this is the later style oil pump/crankcase); Head unloaders- can be piped up for continuous run mode (using a pilot valve) or intermittent operation (using lube oil pressure to work head unloaders). Parts for the disc valves are a bit pricey, but overall, it is a much more rugged compressor. I would make sure it was turning fairly slowly for the cfm needed. Quincy, like any other air compressor manufacturer has a variety of cfm ratings based on crankshaft rpm. Salesmen will tend to take a lighter model and gin it to make the cfm. For a compressor in continuous service, it shortens the life. Go for a bigger compressor, turning a bit slower. It will be quieter, last longer and IMHO, more energy efficient than running a smaller pump at higher speed at the edge of its envelope.

Joe Michaels

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Question - Air Compressors


Jun-Aire 12 gallon twin cylinder compressor. Expensive, amazingly quiet, worth fixing, but again, expensive.
Hitacchi portable work site compressor that is uber high speed, oil cooled, and can stop your heart when it turns on. I got this in trade, and I don't think I would go out and buy one just because of the noise level. It is also relatively small and can really only run a single tool without being constantly on.
Best balance between the 2 is the California Air 4.6 gallon compressor that I have on the Wizard. I don't recall the exact price, but they were rebranded and on sale at Costco for around $200.00. I've been using it for 15 years or so. It has only had one problem, though almost fatal, in one of the high pressure lines blew in the middle of the night (I forgot to turn it off) and by the time I got in the next morning you could smell the heat.
I replaced the rinky-diny tube with an industrial one and it's been fine ever since.
If I were to be on the market, depending on the volume of air needed, I would look at the California air machines first.
Edit: This is the newer version of the one I have.

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Edit: Check the archives for these compressors. There were a number purchased at that time because of the deal, but not everyone was as happy with the product as I was/am.

I have three that have all lasted quite a long time.Jun-Aire 12 gallon twin cylinder compressor. Expensive, amazingly quiet, worth fixing, but again, expensive.Hitacchi portable work site compressor that is uber high speed, oil cooled, and can stop your heart when it turns on. I got this in trade, and I don't think I would go out and buy one just because of the noise level. It is also relatively small and can really only run a single tool without being constantly on.Best balance between the 2 is the California Air 4.6 gallon compressor that I have on the Wizard. I don't recall the exact price, but they were rebranded and on sale at Costco for around $200.00. I've been using it for 15 years or so. It has only had one problem, though almost fatal, in one of the high pressure lines blew in the middle of the night (I forgot to turn it off) and by the time I got in the next morning you could smell the heat.I replaced the rinky-diny tube with an industrial one and it's been fine ever since.If I were to be on the market, depending on the volume of air needed, I would look at the California air machines first.Edit: This is the newer version of the one I have.The cabinet shop I was part owner in at one time had an Ingersol-Rand 200 gallon (twin 100 gallon) tank, 7.5 HP 220 3-phase compressor, and a huge air drier. I miss having that much capability, but not having to wear hearing protection all the time.Edit: Check the archives for these compressors. There were a number purchased at that time because of the deal, but not everyone was as happy with the product as I was/am.

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