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BeeTX 02-05-2007 11:06 PM

Air regulator capacity/location?
I'm getting ready to put in copper air lines, and already had a Jet regulator/filter that I was going to put at the end, but realized it says the max incoming capacity is 160 psi. My compressor goes up to 175 psi, so I thought about putting another regulator (no filter) at the compressor. But for a few more dollars, I could just get a better regulator/filter like the Sharpe 880A some of you have mentioned here. Haven't found a max pressure for it though, when I called Sharpe, I got a guy who sounded like he probably does electronic warranties too. First he said the max it could handle was 165 psi, then when I said I needed at least 175, he said it was 175(???). I'm talking about incoming pressure, not the max gauge or output pressure.

So does anybody know what the Sharpe's max is? I don't get why you'd have a regulator that needs another regulator (like the one I have seems to be), lot of 2 stage compressors out there. Or is there a another setup, or regulator/filter you'd recommend?

Richard H. 02-06-2007 07:58 AM

First off you can adjust the EP switch down to 160 psi , and second I would not use copper for supply. If you insist on it then use hard copper and fittings with sil-flos. I do have the 880 and it is nice.

joe_padavano 02-06-2007 08:53 AM


Originally Posted by BeeTX
I'm getting ready to put in copper air lines,

Isn't copper a little dicey for 175 psi? Iron pipe is the usual piping material for air lines both for the pressure and for the thermal mass that will cause the residual moisture in the air to condense out.

oldred 02-06-2007 10:04 AM

Copper is better than iron for heat dissipation but either will work just fine and although I am not saying it is ok (it is not ok!) I have seen that 880 Sharpe connected to supply lines running well in excess of 175 PSI. It is common practice around the mining areas I serviced to overpressure compressors to maximize tool performance even though this is dangerous and detrimental to tool life it is still done. Don't mess with the regulator setting on that compressor even to lower it because it is the design setting for that motor/pump/tank combo and will be the most efficient setting. The Sharpe 880A is an EXCELLENT choice and 175 PSI will be just fine for that unit.

Richard H. 02-06-2007 11:22 AM


Originally Posted by oldred
. Don't mess with the regulator setting on that compressor even to lower it because it is the design setting for that motor/pump/tank combo and will be the most efficient setting. The Sharpe 880A is an EXCELLENT choice and 175 PSI will be just fine for that unit.

I don't agree , sorry, he is not talking continuous shop duty here and he does want to use his Jet regulator if he can ( which would probably be fine at 175 psi) especially since it is already out of warranty. I keep my 7.5 / 60 gal. at 135 normally and if I am going to spray paint or blast i crank it up. It really all depends on the amount of volume of air he has available.

oldred 02-06-2007 01:51 PM

Richard, There is nothing to be gained from dropping the pressure it only makes your compressor less efficient. Depending on pump design and driven speed the design shut off setting is optimized for that tank size and HP rating and to change this setting only wastes power. Sorry but I have sold and serviced compressors and air systems for both shop and mobile maintenance rigs for about thirty years and it has been my experience that tinkering with that pressure switch usually leads to trouble and rarely if ever provides any benefit. As far as the regulator I would never tell anyone to exceed the max inlet pressure but I have seen many such regulators run for years on settings higher than 175 PSI with no problems, some as high as 250 PSI :pain: I have no personal experience with that Jet but 15 PSI over pressure is not very likely to hurt anything and that Sharpe would in all likelihood stand a great deal more than that, I can safely say there are thousands of them at this minute hooked up to 175 PSI and higher.

As an added note since I have mentioned these higher pressures, I am not saying it is ok to run higher than 175 PSI and in fact I have for years warned against this but it is a fact that a lot of people do. It is a bad idea because it is not only dangerous but there simply is no logical reason to do it. That shut off pressure was chosen by the engineers who designed that compressor and not by the shop janitor so if there was any major benefit to any other setting then that is the way it would have been supplied. My advice based on over thirty years experience with these things is to leave that pressure switch alone.

boatbob2 02-06-2007 05:28 PM

air lines
hi,as other guys here have said,only run steel pipe for your air lines. BUT put a large U bend in the pipe(using 90 % elbows(4 of them) make the bend at least 2 feet long,and put a garden hose bib in the center of the bend (at bottom) that way the water will collect there (condensation) and you can drain it using the hose bib. im boatbob2

oldred 02-06-2007 09:50 PM

Why only use iron pipe? Copper is a better choice in about every respect except for price (the price is staggering compared to iron) copper will cool better, will not rust inside and is easy to work with. Type "L" 3/4" pipe is pressure rated at nearly 600 PSI which is more than strong enough for air lines and is commonly used for shop air systems.

BeeTX 02-06-2007 10:54 PM

Here's a link to tables for type M pipe. 3/4 " at 150 deg F. holds 346 psi working pressure. Actual burst tables show 4700 psi (wow). And the price has come down some lately, $15 for 10 ft. of type M. :) Solder I'll use is 95-5 tin-antimony. I agree with oldred for his listed reasons, my decision on copper was partly from his posts here. I think you guys will find his experience is very valuable if you read his many detailed posts on air related topics. Thanks for the clarification on why not to lower pressure cutoff oldred, the machine/paint shop here did that on theirs and recommended it to me (not that I was going to). Your explanation makes sense.

I have a pretty good idea on the airlines, I've done a couple before with downward slope, leg coming off the top and drains at low points. Just wanted to know if the Sharpe's showed a max on them. Sounds like it'll work. Maybe the Jet would too, although I noticed tonight it says 150 psi max on the unit, could be outlet though as that's what the max gauge reading is. The globe on it is glass, if there's any chance of it blowing not worth it as I have 2 little boys who come to the garage often. I just don't want to buy another that can't handle the pressure (sounds like me in a job I had once :D ).

11echo 02-08-2007 03:49 PM

Left field suggestion ...Use schedule 40 PVC plastic pipe! I have an air system in my garage where I used a 2" sch.40 PVC main header in the rafters and ran 3/4" down to each air station, and then changed to 3/4" galv. pipe and threaded fitting on the walls. This is held in place with uni-strut. The PVC is cheap and easy to work with. It'll (sch.40) easily hold 175 psi air, and I used 2" main header to "help" as a reservoir. That was 2 yr.s ago, still no problems at this time, and I don't have to worry about rust in those sections of the system. My $0.02 anyway, Good Luck! ...Mark

oldred 02-08-2007 05:35 PM

Echo, This subject about PVC has been discussed to death here. PVC is about the worst choice you can make for air pipe because in addition to the fact it is VERY dangerous (especially that 2" section :pain: ) it is by far the worst thing you could use for moisture control except for maybe rubber hose. It has been banned by both OSHA and IMSHA to transport compressed gas including air due to injuries that have occurred when that stuff ruptured and threw razor sharp shards of plastic, IT DOES HAPPEN! The pressure rating on PVC does not in any way make it safe because that rating changes drastically with age and relatively minor temperature changes and even if it is operating within the proper temp range a blow from a hard object, blunt or sharp, can cause it to rupture. If you have PVC for your set-up you would be well advised to scrap that junk before hurting your self or someone else. Some people will scoff at this and point to systems that have worked ok for years but the fact that some gotten away with it still does not make it safe because some have not! Make no mistake it is dangerous and it can hurt you :nono:

11echo 02-09-2007 08:52 AM

OLDRED ...What you have stated is true! AND if I had a shop open to the public I would not have used PVC. But I did use PVC and that is why I put it up in the rafters, it is not subject to "hard object, blunt or sharp objects" and is located in an area where "IF" it did rupture the "shrapnel" would only upset my insulation and my wife's old curtains (no big lost there) All the exposed air system is sch.40 galv. steel pipe. Now I know that OSHA has a "thing" about public safety, and some of the people you meet need all the help they can get, but this is my shop, only I work in it and I take responsibility for that! If I mess up I'm the guy that has to pay the bill. And I'm not going to run out and try to sue somebody because I hurt myself on or with their equipment. Dangerous? ...Yes, but so is the table saw I use to cut wood with. You pay your money and you take your chances! ...My $0.02!

oldred 02-09-2007 09:14 AM

Echo, If you are so aware of the known dangers then why in gods name would recommend it for someone else? :rolleyes: The moisture problem alone is enough not to use it and before you come back with the "my air is dry" argument let me point out that I have replaced several PVC piping systems because of water problems which is usually the case. For someone to take a chance like that with their own safety is irresponsible but to suggest to someone to do it who may not be aware of the the hazards is just plain inexcusable!

Irelands child 02-09-2007 10:22 AM

PVC = bad news for air lines. I did a very temporary setup with PVC. Then it was going on longer then temporary so I took it down and put up copper (still not the best). Each joint where I had used PVC cement fractured as I was disassembling it. Not just broke, but shattered in several small and very sharp pieces. This was brand new Charlotte Pipe PVC, manufactured in 2006 and installed by me in July 2006. Learn my lesson - sure did. There are several other threads here in the last year or so as well decrying the use of PVC and defining what are the best piping systems - and by real experts. Don't - it is beyond inexcuseable and is irresponsible if you have prior knowledge and possible illegal. If your air system injures someone and you are sued, this thread is public can be used as evidence.


11echo 02-09-2007 10:42 AM

Oldred ...I only put it out as a option, the final choice is up to the end user! As far as the "water problem" all you need is low point drain and/or a separator/filter elimainates that issue.
You may have unlimited funds, but most of my life I've had to deal with used or broken equipment I've found in the junk yard or flee markets, and I think that is the case for afew here. But there are options to everything and having to deal with them is apart of this hobby. You think my idea is bad, then don't do it! ...But Please don't try to dicate to me what I can or should do.

P.S. ...I don't have a belt guard on my air compressor, should I go shut it down and not fill up my flat tire?

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