kennyd
Advertiser
John47 said:
Copper pipe is perfectly acceptable in compressed air systems. But I do agree on the PVC though...
plumbing 4 air ?
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Copper pipe is perfectly acceptable in compressed air systems. But I do agree on the PVC though...
Bedlam
Veteran Member
- Joined
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- 1,878
As for the compressor outside what about condensation?
frank_f15
Super Member, Rest in Peace
John47 said:
I AGREE 100% for me it was always black pipe. I ran miles of it over the years in the factory from 4" to 1/4" .Imho pvc can rat to easy and even it the shards don't get , did you ever hear a large 100psi air break, the sound will like to blow your ears out.
IXLR8
Veteran Member
I forgot about PVC's long term degredation.... no PVC for me. Thanks for the reminder.kennyd said:
Are you talking L or M rated copper pipe... or is it all good? I was under the impression one of them was thin wall and was not even rated for 60psi domestic water. It was to be used in low pressure, 15psi, hot water heating systems.
patrick_g
Elite Member
Bedlam said:
Not sure if you refer to the condensation inside the storage tank or on the compressor and motor and controls. The compressor really should be protected from precipitation.
You will virtually always get condensation inside the tank. Running with the tank in a colder environment will cause more condensation in the tank but I look at that as a good thing as that means dryer air coming out. I have seen air lines coming out of the tank going through a heat exchanger to help cool the air which causes more precip to form. The line coming out of the exchanger has a "U" in it with a drain at the bottom.
PVC can work for years in compressed air applications or it might blow up the day you install it. A slight accident like banging the pipe wrong could be a very bad thing.
I am getting ready to install a big upright compressor and plumb my garage and both floors of the shop to it. I will definitely be using the recommended metal pipe, NOT PVC.
I was at a friends place a half mile away recently and noticed he had a new compressor and shop air plumbing, all PVC after the first couple feet so the plastic wasn't in contact with any hot metal. I asked if that didn't make hom nervous and he said, "well its rated for the pressure and it is a lot cheaper!" My comment was, "what are your eyes and other body parts worth to you and is it worth the risk?"
I had to let it go as his mind was made up and there was no way anyone was going to confuse him with facts.
You can walk across the street without looking either way and get away with it several times perhaps but does that make it a smart idea? I drive a Prius and you will never hear me coming!
Pat
Kays Supply
Veteran Member
I worked at a factory that had 2" sch 80 PVC air lines. I came to work one day and there was a large hole in the back of the building. A 2" PVC 90 had blew off and went out the back of the metal building. Every house I have plumbed in the last 25yrs has had M copper water lines. My shop is over 20yrs old and the air lines are all M copper. My father's shop was black iron. He was constantly fighting rust in his water separator and pressure regulators.
A BIG problem with PVC airlines is there is often just a smidgen of oil in the air from the air compressor, and oil and plastic don't mix longterm. It doesn't cause problems for years, but eventually things let go. IMO, I never use PVC in anything under continuous pressure greater than about 60 PSI max, and then only cold water, nothing else. I've seen too many problems longterm.
RPK
Silver Member
Type M copper is used for hydronic heat piping. It is designed for lower pressure and has red labeling on it. Type L is used for domestic water piping and is thicker. It will withstand a higher pressure and has blue labeling on it.
I have only seen black iron pipe for air lines. Either threaded or welded.
RPK
I have only seen black iron pipe for air lines. Either threaded or welded.
RPK
kennyd
Advertiser
IXLR8 said:
Sorry, I should have clarified that...
Type L or K is good for compressed air, NOT type M.
IXLR8
Veteran Member
I found a web site, copper.org, that has charts showing the rated internal working pressures of K, L, M, DWV copper tubing. Diameter of tubing mattered, larger diameter had lower working pressure. The 1" M tubing was rated at 337psi and the 1" L tubing was rated at 494 psi. Sounds like either would work, unless I am mis-understanding the charts. Although what you use to join the tubing matters. According to the charts there, if one used 50-50 solder the working pressure is only 200 psi for 1", or less, tubing. If 95-5 solder is used, the pressure rating for that fitting is 1090 psi. All these numbers are based on a working temperature of 100dF or less. Ratings drop off as the temperature goes up. I know I won't be using the 50-50 solder to make the joints for compressed air lines that might be running 175lbs.
