Compressed air piping

[McRabbet]

I am a proponent of metal versus plastic and have the RapidAir 3/4" system that is easy to install and reliable. Here is a good starting Kit from Northern Tool. While it is not cheap, it is much easier than soldering thick wall copper or running black pipe.

 

[mkepke]

I’ve used one Sharkbite to solve a problematic connection in my Rapid Air system. No complaints after a couple years.

Using Sharkbites + copper everywhere sounds like the most expensive option possible.

-Mark

 

[tvrgeek]

Soldering is Soooo easy. Hard to see why some are afraid of it. Far easier than paying for a SharkBite! I know many a system that has been use for longer than I have been alive ( and that is a LONG time) without any magic creep.

Black pipe is harder to deal with without a big heavy threading machine, but it is not hard. It does rust though.

 

[wolfsburged]

3/4" copper main trunk lines. No issues with pressure drop or leaks, no worries about plastic getting brittle, no worries about iron pipe rusting.

I have an 80 gallon 5 HP compressor located in my basement. Vertical tank - I removed the pump and motor and put those separately on a wooden mount to reduce the height of the compressor to fit in a smaller space.

Biggest improvement for me was installing an aftercooler between the compressor pump and the tank. I have it fitted with an old microwave/hood blower fan which is tied to run anytime I have the compressor switched on. Then a drip leg out of the cooler with a tee fitting off to the tank. Bottom of the drip leg I have a timer/automatic solenoid drain valve. No water gets into the tank to have to drain, and no water or moisture ever in the lines. I have a sandblaster cabinet and I can blast all day with nice dry air.

 

[tvrgeek]

On an old compressor, I had a condenser by running 25 feet of copper tube in a coil between the head and tank. Still filled the tank with water, but the air was drier. Big shops actually have refrigerated condensers.

Larger lines work as additional tank.

 

[kelLOGg]

I used soldered copper.

 

[Hmerkle]

I personally not a fan, I have had them leak on plumbing more than once. Biggest problem is usually the connection was not cleaned correctly or the push-click function was not fully engaged or it just failed. On projects I manage these are usualy what comes with a insta-hot faucet heater, a water cooler or water filter in those package kits.

Agreed - but I see a difference between "brand" Sharkbite and the knock-offs.
A few years ago now - a plumber installed the hot water heater and used it, but my BIL (Plumbing distributor) said he down-sized the fittings, so we replaced them and saw increased water flow! no leaks for at least two years!
My real curiosity is if it would work with air... Logically it should... and Pex is SO easy!

 

[tvrgeek]

PEX pressure rating is a LOT less. Maybe if you ran after a regulator at less than 120 you woudl be OK. Test is only 160 PSI @ 74 degrees. You water lines should never exceed 80 PSI. 60 is more the target for domestic.

 

[Oka]

Most Pipe will have on it WOG 300-480psi or a specific number rating. "WOG means"- water or gas. The fittings specs you have to look up on line in the pdf that is called spec data.

 

[Hmerkle]

PEX pressure rating is a LOT less. Maybe if you ran after a regulator at less than 120 you woudl be OK. Test is only 160 PSI @ 74 degrees. You water lines should never exceed 80 PSI. 60 is more the target for domestic.

I just found this - What Do You Need to Know About PEX? | Plumber Magazine

"PEX-a pipe can withstand a burst pressure of around 800 psi"

 

[RoyWarren]

I have used 1/2" Sch 40 PVC pipe for 25 years in my shop, with no problems. It is rated at 600 psi. My compressor is set for around 100 psi, which is what most of my air tools require. It's stronger that the rubber (plastic) hose that you attach to it. BTW my shop is not climate controlled. So 90s in the Summer and teens in the Winter.

Roy - Waxhaw NC

 

[Oka]

Pex pipe depending on the type is strong. There are different types beside the orange and blue at the big box stores. THE issue with Pex is the fittings they are not as robust not do they resist the higher impact effect (pipe hammer) of rapid pressure changes.
Lots of common sense rules on this. a good rule of thumb is psi rating x .65 is max working pressure. This allows for a good safety factor. Also, all p[lastic to metal connections should always be a plastic male adapter into a female metal fitting. That way if the plastic does expand it has the metal to resist at the transition connection.

 

[Dee2]

Thanks for the thoughts.
FWIW, I have sky lights and fluorescent bulbs. Lots of UV. As I understand, PEX and UV don't mix. Of course the AL pipe systems all seem to be coated with PEX. Hhhmmm.

 

[Jeremy Scuteri]

I have RapidAir in my shop. It was easy to install.

 

[Barry W]

RapidAir 3/4" here. I like the pretty blue color of the tubing.

 

[tvrgeek]

Pex pipe depending on the type is strong. There are different types beside the orange and blue at the big box stores. THE issue with Pex is the fittings they are not as robust not do they resist the higher impact effect (pipe hammer) of rapid pressure changes.
Lots of common sense rules on this. a good rule of thumb is psi rating x .65 is max working pressure. This allows for a good safety factor. Also, all p[lastic to metal connections should always be a plastic male adapter into a female metal fitting. That way if the plastic does expand it has the metal to resist at the transition connection.

Virtually all PEX connectors are male. Even SharkBite internally. I do not know where you got your idea of expanding or weak connectors.

Three types. PEX A, B, and pretty rare C. The Borg carries B. Red, Blue and white. Never seen orange.

PEX A, B or C - Understanding the Differences :: Apollo Valves. It is basically HDPE and very tough.

" In accordance with ASTM F876, the minimum hydrostatic burst pressure for PEX pipe is 480 pounds per square inch (for 1/2-inch pipe) and 475 psi (for 3/4-inch pipe and larger) at 73.4 degrees F."

If I had my choice, I would use A. Even for the Milwaukee expansion tool ( $400) it looks like the better system as it can have fewer connectors and their ID is the same as the pipe. Manual tools are more like $100, similar to type B crimper's. But A is a bit more expensive as it is only a couple of brands.

PVC and CPCV are also very tough, but really fall off with heat. @ 140 F it is only 20% as strong as at 72 degrees. Basically working pressure of under 80 for schedule 40. Now one's DHW should not be that high and neither is our air lines. Very easy to work with and no special tools. It is not recommended for DHW even though the Borg sells it as such. ( usually against code)

PEX and PVC both break down with UV light so should never be left exposed. Another win for plain old copper! It would be hard for me to understand someone with minimal workshop skills such as a woodworker to not be able to sweat copper.

There are contradictory numbers given for lifespan. From a low of 25 years ( sounds like plumbers looking for work) to a more reasonable 80 to 100 years.

 

[RoyWarren]

I believe some are judging PVC and PEX on numbers associated with using it as water pipes. Yes, PVC will freeze up and since water expands it can burst the pipes.
I don't believe this is the case with air pressure. PEX or copper seems like an overkill to me.

Roy - Waxhaw, NC

 

[tvrgeek]

I believe some are judging PVC and PEX on numbers associated with using it as water pipes. Yes, PVC will freeze up and since water expands it can burst the pipes.
I don't believe this is the case with air pressure. PEX or copper seems like an overkill to me.

Roy - Waxhaw, NC

Burst pressure is burst pressure. PEX is cheap if you have the crimper or expander. Sharkbites are expensive. Don't forget to add up the various adapters to connect to your separator and regulator, and what you want as a rigid mount for the female ends.