Running 250psi- what piping system?

[tarbellb]

I will be installing machinery that needs 15.5bar / 215 psi constant pressure.

Going over my notes and research this is the upper end or beyond most typical piping systems

What are the industry standard systems for this kind of pressure, what should I be considering?

System scope:
Looking to pipe machine at high pressure then pipe remaining system down to 175psi

215psi @ 10+ cfm (machine only) 15ft run
Shop is less 150ft total pipe
needs to be extremely clean+dry air
would like to run 175psi @ 20cfm on the lower pressure side

I'm thinking 1" Copper L or K and solder joints from the compressor to machine (on board regulator) and mainline regulator

Then neck down to 3/4" pex al pex system post regulator to 1/2" drops

 

[toplessHO]

I would use black Iron

 

[theoldwizard1]

Type K copper. Good for over 400 psi. Braze instead of solder.

 

[larry4406]

I worked at a power station many years ago. They were running copper air lines. I recall it being either silver soldered or brazed.

I have the attached Copper Tube Handbook saved on my computer. Maybe it is helpful.

 

[whateg01]

No PVC?

Does there need to be some flexure at the machine end?

 

[MacMcMacmac]

Black iron lasts a long time with dry air.

250psi is nothing for it.

 

[willf650]

Black iron lasts a long time with dry air.

215psi is nothing for it.

Standard sch 40 screw fittings are only rated for 150#. You would have to step up to Sch80 fittings I believe but don't quote me on that as I would have to look up the specs but think it would meet them,

I would use copper and braze the joints. If you don't want to deal with purging technically 95/5 soft solder would be rated for the pressures you are working at but the generic 50/50 equivalent probably wouldn't be. They do make some soft solder for refrigeration lines that would be suitable as well.

 

[LopezBart]

Sil-Phos is a very useful self-fluxing brazing alloy for copper; it's widely used for refrigeration, and is much cheaper and easier to use for pure copper than high silver alloys.

If you go with black iron pipe, steel hydraulic fittings are less expensive than class 300 fittings.

 

[matt_i]

JW Harris Sta-Brite #8 solder for the win. You will think you're using leaded solder but it's approved for potable water systems. Approx 10ksi in tight shear like in a typical copper joint. Use Sta Clean flux from same mfg.

Hydraulic tubing with JIC flares would also be nice looking and plenty of safety factor. Plated steel fittings are not crazy expensive.

 

[1Bad55Chevy]

Standard sch 40 screw fittings are only rated for 150#. You would have to step up to Sch80 fittings I believe but don't quote me on that as I would have to look up the specs but think it would meet them,

I would use copper and braze the joints. If you don't want to deal with purging technically 95/5 soft solder would be rated for the pressures you are working at but the generic 50/50 equivalent probably wouldn't be. They do make some soft solder for refrigeration lines that would be suitable as well.

I know nothing about this but 150psi seems on the light side of schedule 40. I think the PEX tubing in my shop is rated that high. I found this chart online comparing 40 to 80 but idk if its true or not.

SCH 40 vs SCH 80 Steel Pipe Pressure Rating - Knowledge - Gnee Steel

SCH 40 vs SCH 80 Steel Pipe Pressure Rating

m.baosteelpipes.com

Again idk anything about this, just comparing my PEX to steel.

 

[micromind]

I think you should use 6" PVC. That way when it blows, it'll be spectacular!

Yes, schedule 40 (standard) galv and black iron are technically rated at 150 PSI but I've seen both used at much higher pressure.

Not sure but I believe the pipe is rated higher and the fittings are 150.

 

[Wfallison]

Standard sch 40 screw fittings are only rated for 150#. You would have to step up to Sch80 fittings I believe but don't quote me on that as I would have to look up the specs but think it would meet them,

I would use copper and braze the joints. If you don't want to deal with purging technically 95/5 soft solder would be rated for the pressures you are working at but the generic 50/50 equivalent probably wouldn't be. They do make some soft solder for refrigeration lines that would

Per ASME/ANSI B16.5, Class 150 malleable iron fittings have a maximum allowable pressure (MAWP) of 300 psi at 150 degrees F. 1" Schedule 40 pipe has a MAWP of >4000 psi at 200F.

 

[scooby074]

"Extremely clean" and high pressure immediately brings "Whats your definition of extreme clean, whats your budget" to mind. Id say Swagelok products, but that will make the baby Jesus cry.

 

[MacMcMacmac]

We are running 300psi through sch40 8" pipes at work. The burst pressure is over 4000psi.

Check out the 200psi copper pressure test caps. They are almost paper thin.

 

[Beerhippie]

This is for a workplace? Check with your local inspector and insurance inspector--they're the ones who will be signing off on it.

We used to run 300psi CO2 in soft-soldered Type L copper. Never had a problem with it--aside from constantly dripping condensation on the outside of the lines. Finally got a new boss who listened to reason and dropped the pressure to 125 psi, allowing me to use PEX. Pre-existing copper is still going strong about 30 years on.

 

[finn]

Welded stainless steel.

 

[Snapped-off]

We used inconel piping for our 4,500psi high pressure air systems on submarines. That should do the trick just fine. All joints were welded.

 

[tarbellb]

For the flex line I'll just use a rated hose whip, most are rated for 300psi.

Id rather not do iron pipe, corrosion is a concern, even if I'm running all dry, clean air...

will any of the copper ProPress tools from the cordless mfg do 300psi rated fit up?

I'm leaning towards brazed copper L/k pipe but sure wouldn't mind adding a propress tool for future plumbing jobs ????

 

[tarbellb]

This is for a home shop, so I don't need it inspected or signed off
Cost is always a concern, but doing it right and once is my typical move

Stainless feels like its going to cost to much, at least compared to copper. Prove me wrong I guess?

Any pex/al/pex mfg making 250psi + systems?

 

[The Cobbler]

Check out the 200psi copper pressure test caps. They are almost paper thin.

they are not made for permanent install. just for testing

 

[The Cobbler]

I agree the black pipe is probably the most economical way to get that pressure rating .silver soldered type L copper would be up there too but more costly for materials

 

[Shiftless]

215psi @ 10+ cfm (machine only) 15ft run

This is for a home shop, so I don't need it inspected or signed off

Very impressive. Sounds like quite serious work for a “home” shop. If something catastrophic happened would your home insurance cover it? Mine would not. Are you self insured?

 

[strength_and_power]

Strictly curiosity, what machine needs that kind of pressure?

 

[tarbellb]

Very impressive. Sounds like quite serious work for a “home” shop. If something catastrophic happened would your home insurance cover it? Mine would not. Are you self insured?

Appreciate the concern, will try to keep catastrophies to a minimum.

Strictly curiosity, what machine needs that kind of pressure?

Fiber laser machine

 

[john.k]

If its a budget job, black truck air brake pipe is suitable for small airflow ,up to around 25cfm ......biggest size is 1/2'' bore ,but the smooth interior flows a lot more than youd expect ....push in fittting simplifies installation...........Ive used this tube for many budget industrial jobs where cost was a major consideration ...........you can double the flow with two pipes if you like

 

[Mr onetwo]

Type L copper brazed with Harris Stay-Silv 5% and flux. Run nitrogen thru it when brazing....easy peazy

 

[welder4956]

We used inconel piping for our 4,500psi high pressure air systems on submarines. That should do the trick just fine. All joints were welded.

All the ones I welded for TDU or ejection air were 304 stainless. But that was hull numbers older than 672. Although I can see where using Inconel would allow for thinner piping with less weight.

 

[welder4956]

I agree with those recommending Type K or L copper pipe with silver solder. The downside of schedule 40 carbon steel is that threaded joints cut pretty deep and I have seen them fail at the threads in industrial cooling water systems at 150-250 psi. All of our power plant service air piping was either brazed copper or 0.065" wall stainless tubing.

 

[mike93lx]

For the flex line I'll just use a rated hose whip, most are rated for 300psi.

Id rather not do iron pipe, corrosion is a concern, even if I'm running all dry, clean air...

will any of the copper ProPress tools from the cordless mfg do 300psi rated fit up?

I'm leaning towards brazed copper L/k pipe but sure wouldn't mind adding a propress tool for future plumbing jobs ????

Viega is rated to 200 for air, 300 for water. Nibco is also 200 for regular, but they do have a refrigeration line that is rated higher, although I can't find anywhere that they offer a spec for compressed air

Propress is pretty great and I love having a tool, but I don't know if i' d push it constantly past the rating

 

[mike93lx]

If its a budget job, black truck air brake pipe is suitable for small airflow ,up to around 25cfm ......biggest size is 1/2'' bore ,but the smooth interior flows a lot more than youd expect ....push in fittting simplifies installation...........Ive used this tube for many budget industrial jobs where cost was a major consideration ...........you can double the flow with two pipes if you like

That's rated for these pressures?

 

[Snapped-off]

All the ones I welded for TDU or ejection air were 304 stainless. But that was hull numbers older than 672. Although I can see where using Inconel would allow for thinner piping with less weight.

688's have no air piping for the TDU. There's just a vent to equalize the tube to sea pressure, before opening the muzzle ball valve.

 

[Snapped-off]

That's rated for these pressures?

Looks like working pressures are 150 - 500. Just depends on the brand.

 

[mike93lx]

Looks like working pressures are 150 - 500. Just depends on the brand.

I'm surprised it's that high. An on board compressor shouldn't be anywhere near 500, right?

 

[Snapped-off]

I'm surprised it's that high. An on board compressor shouldn't be anywhere near 500, right?

May be misadvertised burst pressure, I'm not sure. They were no-name brands.

Parker advertises 150 working.

 

[mike93lx]

May be misadvertised burst pressure, I'm not sure. They were no-name brands.

Parker advertises 150 working.

I'd trust Parker.

On propress, it's 200 working, 600 burst. I wouldn't run it for the OP's application