Black pipe or galvanized for shop air lines?

[dragoneggs]

My business is my livelyhood and believe me I don't need any down time. In 1984 when I put up the building, the air lines installed were PVC, and they have serviced me well for 30 years, with 0 failures. They have carried about 165 psi 6 days a week for 30 years.

Schedule 40 or 80?

 

[ultrarunner]

Could be Schedule 120 with working pressures of over 1000 psi for 1/2 inch and 720 psi for 1"?

Here is a safety data link for PVC and CPVC

Cautions Areas

 

[boggen]

My business is my livelyhood and believe me I don't need any down time. In 1984 when I put up the building, the air lines installed were PVC, and they have serviced me well for 30 years, with 0 failures. They have carried about 165 psi 6 days a week for 30 years.

i would say ya living on great luck! vs me were murphy law normally shows it's ugly rear.

pressure testing plumbing for water, and having test plugs shoot out, to cutting pvc pipe, to dealing with frozen water lines. having joints fail, seeing difference between PVC outside in the sun for a few days, vs not in the sun and watching the one in the sun shatter in my hand, to many things add up quickly of uglyness when pvc + compressed air are combined.

 

[Buckgnarly]

My business is my livelyhood and believe me I don't need any down time. In 1984 when I put up the building, the air lines installed were PVC, and they have serviced me well for 30 years, with 0 failures. They have carried about 165 psi 6 days a week for 30 years.

Show me anywhere that says PVC is rated for air. There are far more dangerous blowouts with PVC than the proper methods like Cu or iron. I'm quite surprised that a business owner would be proud of doing something dangerous and the improper way....:2cents:

I am the last person to tout gov regulation, but when it means the lives of people....
https://www.osha.gov/dts/hib/hib_data/hib19880520.html

 

[JRP]

A few more thougths. PVC can shatter and make a large air leak. One coworker came to work and said his compressor burned up after the PVC shattered. Piston compressors are designed to run at or less than 50% duty ( on-off time) and when you exceed 50% eventually the compressor burns up.

I turn off my compressor breaker as I turn off the lights. Also have considered adding a timer that shuts down automatic operation if the compressor is running for more than 30 minutes, in case of air leaks.

Use large diameter pipe or PEX. 3/4" or 1" If you can. It reduces pressure drop and adds system capacity.

 

[Dave M7040]

I'm about to do my shop with air lines, but I would not use rubber hoses because I've had so many of them fail during the construction of the house. They eventually crack and begin to leak. Plus you have to mount it and create drops that allow quick disconnects without flexing very much. PEX is not good enough for me because it is so close to it's design limit of about 100 PSI at 180 degrees or 180 PSI at 70 degrees. This means a regulator and reduced pressure to the air supply lines if you have a 2 stage compressor.

For me copper makes the most sense, but black or galvy look very good too. These offer a permanent, safe and easy to connect to manifold.


One problem is getting from the compressor to the wall mounted regulator on my setup. That flexible hose keeps failing. It sits at full pressure and eventually cracks.

For the hose that keeps failing, have your local hydraulic supplier make you up a line. Their hoses are good in cold, rated for 2-3,000 psi. Will never fail in your application.
Dave M7040

 

[ray66v]

My business is my livelyhood and believe me I don't need any down time. In 1984 when I put up the building, the air lines installed were PVC, and they have serviced me well for 30 years, with 0 failures. They have carried about 165 psi 6 days a week for 30 years.

Are you are suggesting that since you have been lucky, and not had an accident, that there is not an issue here?

The dangers of using PVC for compressed air have been well documented, and known since 1972. Numerous people have been injured by PVC airlines, myself included. If you spend a few minutes searching for the information about this hazard, it's all available to you.

PVC air lines do not meet building codes, or OSHA requirements, because they are not safe in this application.

You are risking losing your livelihood, while you ignore the documented reality on this issue.

 

[Raspy]

For the hose that keeps failing, have your local hydraulic supplier make you up a line. Their hoses are good in cold, rated for 2-3,000 psi. Will never fail in your application.
Dave M7040

Thanks Dave, I never thought of using hydraulic hose.

 

[ray66v]

Thanks Dave, I never thought of using hydraulic hose.

They also work well for a vibration isolator in air lines.

 

[rswyan]

A few more thougths. PVC can shatter and make a large air leak. One coworker came to work and said his compressor burned up after the PVC shattered. Piston compressors are designed to run at or less than 50% duty ( on-off time) and when you exceed 50% eventually the compressor burns up.

I turn off my compressor breaker as I turn off the lights. ...

A very good idea ...

I had two recent instances where I had flipped the on/off switch - which appears to be spring-loaded - on my large compressor to "off" ... and it flipped back on of it's own accord.

Bad idea: leaving air hoses connected to a compressor ... especially one that is left on.

Good idea: installing a on/off valve directly on the compressor outlet itself ... and getting in the habit of always closing it when leaving the shop.

 

[ultrarunner]

At work the compressor contact switch fused and the compressor ran all weekend until it got so hot the thermal circuit breaker tripped... the room became extremely warm.

Problem is air is needed 24/7 for process equipment...

Since then I change out the contacts every 3 years.

To my amazement... the motor was ok once it cooled... this was 6 years ago...

The old compressor dating from the 50's had a mercury switch contactor just like our old Steam Boilers... in my 23 years the mercury switches performed flawlessly... whomever said they don't make them like they use to was right.

 

[czechsonofagun]

I had copper tubing left over from HVAC project, used that to run the air in my shop since I did not need much.

 

[musselmark]

I know many of you will have a lot of negative things to say about this but I plumbed my shop and 300`under ground line to my house with half inch black poly pipe, I run my air at 125psi and it has been 7 years so far with zero problems and I am in eastern canada with extreme cold winters and pretty hot summers.

 

[boggen]

I know many of you will have a lot of negative things to say about this but I plumbed my shop and 300`under ground line to my house with half inch black poly pipe, I run my air at 125psi and it has been 7 years so far with zero problems and I am in eastern canada with extreme cold winters and pretty hot summers.

black poly pipe is different than the hard plastic pipe that ya pickup at menards, lowes, homedepot, that is used for water lines, and sewage lines. that hard plastic can send out sharpenal like a pipe bomb.

black poly hose is softer material that will more likely stretch and give and burst, without sending out deadly flying objects. granted hard plastic fittings for black poly may not be rated for air is a different story.

 

[ultrarunner]

I worked in a shop with black poly pipe...

We had to shut off the compressor at the end of every work day or else it would leak down and run... this was 30 years ago.

Finally doubled up on the hose clamps and bought better ones... as far as I know it is still in service.

 

[ray66v]

The problem with black ploy pipe in this application is, it substantially loses strength if it's heated.

If you compressor runs hot, you could have air coming out of it, that is hot enough to weaken the pipe. Using steel, or copper for the first section would allow some heat to disperse.

Pex would be a better choice.

 

[541S]

When I did my garage I used Compressed Air System for Shop | Compressed Air Piping for Garage | Home Owner Air Tool Systems specifically made for use with compressed air. It works fine. You may want to check it out.

 

[COL F]

Compressed Air Piping | Compressed Air Systems | Do It Yourself Compressed Air Systems Interesting that rigid aluminum tubing does not appear to have been mentioned....

 

[grizzly802]

I agree with 541S. I worked maintenance in a factory that uses black pipe for drops and we have to change filters in the frl's all the time. I know that's what they're their for but we had to change them too often. I like the Rapid Air products and that's what I'm going to use when I do my shop.

 

[ray66v]

I agree with 541S. I worked maintenance in a factory that uses black pipe for drops and we have to change filters in the frl's all the time. I know that's what they're their for but we had to change them too often. I like the Rapid Air products and that's what I'm going to use when I do my shop.

If you don't have clean, dry air, it doesn't matter what you use for pipe, you will still have problems with your tools.

If you have clean, dry air, black pipe will out last the building, and your tools will be happy.