compressor

[Paul M. Kaplowitz]

I'm thinking about getting a new compressor for my shop. A vertical unit, say 60 gallons that puts out 5+ CFM @ 90PSI or there abouts. It can be 120 or 240V. The unit will be located outside the shop, so I would like a suggestion for type of piping to use. I would be greatful for recommendations. Thanks, pmkappy

 

[Odie]

I'm thinking about getting a new compressor for my shop. A vertical unit, say 60 gallons that puts out 5+ CFM @ 90PSI or there abouts. It can be 120 or 240V. The unit will be located outside the shop, so I would like a suggestion for type of piping to use. I would be greatful for recommendations. Thanks, pmkappy

It seems to be the general consensus that plastic pipe should be avoided.

I'm far from being someone of knowledge about piping, but if you ask Vaughn on this forum.....he seems to know a thing or two about setting up compressors........

ooc

 

[George Clark]

I agree you should avoid hard plastic pipe. Most agree it is dangerous due to the posibility of it bursting from impact and sending pressurized shards flying. Personally, I prefer black pipe and have used it in five different shops over 35 years with no problems.

TP Tools and Equipment is a source for compressors and information on plumbing air lines. I have no affiliation other than being a satisfied user of their information and products.

http://www.tptools.com/

http://www.tptools.com/p/2035,114_Modular-Metal-Piping-Kits.html

George

 

[Vaughn]

I agree with George...black iron pipe is probably the most economical these days, and should last about forever. There is some debate among people who use lots of compressed air (like car painters) about the potential for rust in the lines coming loose and clogging air tools, but I've yet to see anyone who actually had that problem...seems to be more of a theory than a fact.

Galvanized iron pipe is probably the next-cheapest route. (That's what I ended up using, simply because I liked the color better and it wasn't a lot more money.) I've seen debates similar to the black iron arguments...some folks worry that the galvanization will eventually peel and flake off inside the pipe, leading to clogged tools. Again, I've not seen or heard of cases where this happened, just the debate about the possibility of it happening.

Copper pipe is considered by a lot of folks to be better than either black or galvanized pipe, since it's less likely to corrode. It's also easier for a lot of folks to solder joints than it is to cut threads on the pipe and screw it together. (My local hardware store cut and tapped -- at no charge -- all the pipe I bought from them.) These days copper is pretty pricey, but it's another material that should outlast you. It i somewhat more susceptible to denting from getting bumped, though.

I've not had any hands-on experience with the piping kits sold by TP Tools, but I've seen good reviews for the materials. (A bit pricey, though.) The TP Tools site also has a lot of good info and suggestions regarding the piping layout.

And yes, I'd strongly recommend staying away from rigid plastic pipe like PVC. Too many documented horror stories out there to disregard them. Yes, a lot of folks have used it for years with no problems, but the cost savings aren't worth the risk to me.

 

[n7bsn]

Most people posting on the pipes are mostly correct.

Conventional "plastic" pipe, that is ABS or PVC is a really bad idea.

There is a "plastic" pipe that is rated and sound for this application, it's HDPE.

It's rated for this application and is safe and accepted

TTFN
Ralph

 

[Paul M. Kaplowitz]

Thanks for the info on piping. Any recommendations on brands of compressors? pmkappy

 

[Bill Boehme]

Five CFM is pretty low for a large tank vertical compressor. While that is adequate for most things, if you plan to use a HVLP sprayer, I would get one that is able to provide much greater flow rate. For instance, my DeVilbiss gun requires 16 CFM at 30 PSI to the sprayer's regulator. I believe that this necessitates using a two stage compressor since I don't know of a single stage compressor that can provide sufficient flow. I also have a couple Exair vortex cabinet coolers for electrical equipment that require a high flow volume, but their operation is intermittent.

In any case, I recommend that you do NOT get an oil-less type compressor. They are very noisy (much improved over earlier models, but still noisy) and the MTBF of the compressor components seems to be just a few years under relatively light duty use before the flapper valve breaks or some other component such as the piston or sleeve fails. Rebuild kits are available and they are easy to rebuild, but the cost of a kit is absurd considering what you get. My recommendation is to get an oil type compressor with either cast iron cylinders or, if aluminum, then make sure that it has steel sleeves. Nitrided aluminum cylinders just do not hold up well in air compressors. If you have deep pockets, then Ingersol-Rand is a very good brand, but otherwise, I think that they are all about equal.

 

[allen jay]

piping

anything metal other than copper naturally can rust due to moisture. copper is the best option. but pricey. and more time consuming to install unless you use the non solder fittings available but they are really pricey.
not sure what would take more time to install copper with solder fittings or iron or galvanized and having to cut and thread each corner. have used plastic without any problem. one more option is pex pipe.
in regards to the compressor unless youare going to use sanders or air files a two stage from the local big box will work fine. dont get oiless and dont get direct drive.
hvlp guns dont need a huge compressor as they only really need 10 lbs. at the gun. have used mine to spray latex paint with out any problem regarding any loss of pressure.

 

[Vaughn]

Thanks for the info on piping. Any recommendations on brands of compressors? pmkappy

A lot depends on how much you want to spend and how much you plan to use it. Ingersoll Rand and Quincy are two well-regarded brands among the guys who use compressors for a living, but it's real easy to spend over $1000 on one. Campbell Hausfeld makes most of the compressors you see at the big box stores (regardless of the label on the compressor). They do well for a lot of folks, although they are generally not as robust or long-lived as an IR or Quincy. I ended up buying a 60 gallon/5 (true) horsepower single stage rig from Eaton Compressors. It puts out about 19 cfm at 100 psi. Eaton assembles imported parts here in the US and puts together beefy over-engineered systems. So far I've been real happy with my compressor, although there has been some controversy about how Eaton has tried to control what gets posted about them in several forums.

 

[Dick Sowa]

Everyone is saying that PVC is not appropriate or a good idea, but...

Sched 40 pvc is rated for several hundred psi, and I don't think folks shop compressors will be putting out much more than 100-125 psi...I have mine set to max at 110. So except for the physical abuse issue, where metal pipe would be better, why not use pvc?

 

[Steve Worcester]

...hvlp guns dont need a huge compressor as they only really need 10 lbs. at the gun. have used mine to spray latex paint with out any problem regarding any loss of pressure.

For the record, it is usually 10PSI at the cap, not at the gun. My SATA mini-jet is 29 psi at the gun but 5 cfm. Bigger guns go up to about 15 cfm at the same PSI.

Pneumatic sanders are the huge air-hogs in the 10+ CFM at about 90+ PSI.

 

[Steve Worcester]

Everyone is saying that PVC is not appropriate or a good idea, but...

Sched 40 pvc is rated for several hundred psi, and I don't think folks shop compressors will be putting out much more than 100-125 psi...I have mine set to max at 110. So except for the physical abuse issue, where metal pipe would be better, why not use pvc?

It is reputed that PVC breaks down and weakens over time, both from ozone and external environmental factors and the air, particles and minute droplets that run through the inside. The bigger factor, like anything pressurized, is that the brittle exterior (compared to metal) shrapnels if it is hit. In my opinion, not worth the risk.

I am looking at plumbing for a spring air compressor install as well and looking at the options.

 

[Vaughn]

...Sched 40 pvc is rated for several hundred psi, and I don't think folks shop compressors will be putting out much more than 100-125 psi...I have mine set to max at 110. So except for the physical abuse issue, where metal pipe would be better, why not use pvc?

Shattered PVC lines and the shrapnel they produce is a well-documented hazard. (See OSHA) It's not the result of putting too much pressure in the line...it's due to the failure of the pipe at the less-than-rated pressure. When a metal (or flexible plastic) line ruptures, it splits. When a rigid plastic line ruptures, it shoots sharp pointy things all over the place.

Also consider that gasses (like air) compress, whereas liquids don't. A line holding 100 psi of air has a lot more "gallons" of air in it than the gallons of water in an equally-sized line with water at 100 psi. Thus, when the air line does fail, there is a lot more volume flowing out the hole, potentially causing a much more explosive scenario.

Bottom line is that PVC lines do work, but there is a risk factor involved. If the lines are built into walls or otherwise contained, the risk is greatly reduced. If the lines are exposed, the risk is obviously increased. A lot of folks have gotten by for years with exposed PVC lines and had no problems. A lot of folks have also driven cars for years without wearing seat belts. Both groups are taking risks that only they can decide are worth taking. 😉

 

[Bill Boehme]

.... hvlp guns dont need a huge compressor as they only really need 10 lbs. at the gun. have used mine to spray latex paint with out any problem regarding any loss of pressure.

As Steve said, it is 10 PSI at the cap, and in my case, a flow rate of 15 CFM. My DeVilbiss gravity feed HVLP gun nominally requires 30 PSI at the gun which is not the same thing as the regulated output pressure from the tank regulator. The output pressure from the tank needs to be much higher in order to provide the high volumetric air flow rate. My gun uses a special handle mounted regulator which is capable of providing the necessary air flow since the typical air regulator is not capable of providing the necessary flow rate at that output pressure. Additionally, the hose from the tank to the gun has to be at least 1/2" inside diameter -- otherwise, the airflow would be throttled down too much. In order to push the needed volume of air down the hose, the output side of the tank regulator is much higher -- somewhere in the vicinity of 120 PSI which means that the upstream side ought to be around 140 PSI minimum and 175 PSI when fully charged. The tank needs to have adequate volume to keeps the pressure fairly constant and to prevent fast on-off cycling of the compressor. This generally means a two-stage compressor.

The latex spray rigs that I have seen do not require a very high air volume, so we can't really generalize what a latex spray rig uses to a true HVLP system that is shooting polyurethane or lacquer.

There are some little lightweight portable HVLP sprayers around, but I suspect that they are actually pressurizing the finish rather than pumping a large air volume. I have not seen how well they perform, but then they are not air compressors either so not what Paul is looking for.

BTW, I am also looking to upgrade my compressor -- my current one was marginal anyway. Some good advice is to always shut off the compressor when not in the shop -- I forgot a couple years ago and a hose ruptured and caused the compressor to run non-stop for at least 24 hours. When I came into the shop, it was filled with white smoke from the oil cooking and the compressor was so hot that I could feel the heat from several feet away. I could tell by the sound that the piston rings were probably somewhere past the break-in period. 😀

 

[Steve Worcester]

BTW, I am also looking to upgrade my compressor -- my current one was marginal anyway. ....

Me too, this year for sure. Looking at this puppy, need something fairly quiet since it will be in my 2 car garage

http://www.belairecompressors.com/p_qp-quiet-performance.html

At that price though (~$2600), I go into the realm or Hydrovane and rotary screw compressors

 

[Vaughn]

Steve, one of the reasons I went with the Eaton compressor was the advertised noise level of 73 db. It's a lot quieter than the Auto Zone buzz-bomb it replaced. You definitely hear it, but you can have a normal conversation in the shop when it's running. The Belaire you linked to would be even quieter. A lot quieter.

 

[Rick M]

I'm still picking the price/performance point where I'll pull the trigger to add compressed air to my space-challenged setup, but am leaning strongly toward an IR GarageMate until I can step up to something bigger. Although I like what I've found about IR's bigger units, one other brand that should probably on anyone's research list is Rolair Systems.

 

[n7bsn]

Steve, one of the reasons I went with the Eaton compressor was the advertised noise level of 73 db. It's a lot quieter than the Auto Zone buzz-bomb it replaced. You definitely hear it, but you can have a normal conversation in the shop when it's running. The Belaire you linked to would be even quieter. A lot quieter.

It depends on how you define "lot"

Their quietist unit is 7 dB quieter then the one you have. A decrease of 6 dB is 1/4 of the energy. But is it not 1/4 as "loud" since the ear is neither "log" (like dB) nor "linear" (like energy). a decrease of 7dB is not even half as loud.

Half as loud is usually a decrease of 9 or 10 dB (10 dB is one tenth the energy)

A decrease of 7dB is good, any decrease is good.

 

[Wipedout]

I'm thinking about getting a new compressor for my shop. A vertical unit, say 60 gallons that puts out 5+ CFM @ 90PSI or there abouts. It can be 120 or 240V. The unit will be located outside the shop, so I would like a suggestion for type of piping to use. I would be greatful for recommendations. Thanks, pmkappy

Have you looked at the RapidAir piping?

It looks very interesting http://www.rapidairproducts.com/index.asp

 

[Vaughn]

It depends on how you define "lot"

Their quietist unit is 7 dB quieter then the one you have. A decrease of 6 dB is 1/4 of the energy. But is it not 1/4 as "loud" since the ear is neither "log" (like dB) nor "linear" (like energy). a decrease of 7dB is not even half as loud.

Half as loud is usually a decrease of 9 or 10 dB (10 dB is one tenth the energy)

A decrease of 7dB is good, any decrease is good.

Yep, you're right. The emphasis probably should have been on the first "lot"... the difference between my old one and the new one. The additional noise 7dB reduction from the Belaire would indeed be good though.

Rick, I know someone with the GarageMate and he really likes it. I seriously considered it too, but decided I wanted a bigger tank.