compressed air piping system design

[millimeters]

Hi,
I was wondering what is the design standard for the equipment an piping system if pressure is below 15 psi? This a pneumatic system for launching golf ball.
Thanks

 

[handleman]

Based on the golf ball info, it sounds like this line of inquiry should be taken to forum1528. I'd recommend red-flagging this post and re-posting it there.

Additionally, although I'm completely unqualified to comment, if I recall correctly the Canadian piping system requirements for inspection, design checking, etc. don't apply below 15psi, or for plain ol' compressed air below 3/4" pipe size. If it's not plain air, all bets are off.

If this really is a hobby post, just buy standard compressed air components (unless you're using special gases). They're pretty much all rated to at least 60psi.

 

[MFJewell]

I used schedule 80 PVC for a compressed air potato gun. The pipe, valve, and sealant where all rated to over 200 psi. I usually used 80-100 psi in it.

 

[millimeters]

What if pressure go up to 30 psi?

 

[TenPenny]

I believe that if the pressure is over 30 psi, you'll need to refer to your Province's boiler and pressure vessel act, or whatever it's called, if this is for anything other than a personal hobby item.

 

[EngineerTex]

Do not use PVC for compressible fluids. i.e., do not use PVC for potato guns, compressed air or pneumatic golf ball launchers.

(I used PVC successfully for potato guns when I was younger. When I use the term "successfully", I mean it in the sense of only by sheer luck did I not end up blowing up myself or bystanders in the same way that you can find many videos online of people exploding their PVC potato guns)

Engineering is not the science behind building. It is the science behind not building.

 

[LittleInch]

Design standards for low pressure (<15psi) or normally low volume (some small number) are just "general Industrial".

I echo Engineer Tex - Do not use PVC, that stuff explodes like a fragmentation grenade ( been there narrowly escaped).

why though in gods name do you want to fire golf balls?

It's not like tennis where you hit them back???

why can't you just buy one??

http://www.jvdgolf.com/hotshot/

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[pylfrm]

why can't you just buy one??

http://www.jvdgolf.com/hotshot/

Looks like PVC to me.


pylfrm

 

[LittleInch]

Hmmm, I just choose that one at random but the point was it had been designed properly by the looks of it not just glued together in someone's shed.

But if it was pvc I wouldn't touch it either even though you could sue the manufacturer if it blew up in your face.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MFJewell]

Do not use PVC for compressible fluids. i.e., do not use PVC for potato guns, compressed air or pneumatic golf ball launchers.

(I used PVC successfully for potato guns when I was younger. When I use the term "successfully", I mean it in the sense of only by sheer luck did I not end up blowing up myself or bystanders in the same way that you can find many videos online of people exploding their PVC potato guns)

Why not? If everything is assembled correctly and the pressure is controlled to less than 50% of MAWP, what is the issue. I could see not using PVC if it is the combustion type potato gun, since the cylinder pressures and temperatures are uncontrolled, but for compressed air that is fed slowly into the cylinder before each launch, that isn't an issue.

 

[LittleInch]

Because PVC ages, weakens and when it decides it's had enough it fragments.

Most of the joints end up with a large sudden change in cross section which results in high stress concentrations and fatigue at the joints.

https://www.lni.wa.gov/safety/hazardalerts/902.asp

https://www.reddit.com/r/AskEngineers/comments/52kk9a/typ_pvc_pipe_over_pressure_failure/

https://www.osha.gov/dts/hib/hib_data/hib19880520.html

https://plasticpipe.org/pdf/recommendation-b_transport_compressed_gas.pdf

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MFJewell]

All those references are for in service compressed air systems, and I agree that I would not use PVC for a system that is in service all day/every day. But for a hobby launcher that is used occasionally, keep the pressures low and inspect it before use.

That said, I do plan to make another metallic version, so I can run higher pressure and see how far I can get a potato bullet to go.