Pressure tube
Does anyone know how much pressure 2.00″x .120″ wall chromolly can hold? I want to make something and I want to be able to run up to 4500 psi in it.
It will be 3.5″ long and threaded on both ends so probably .100″ thick where the threads are.
Thanks
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Viewing 14 replies - 1 through 14 (of 14 total)
Thanks.
What threads are on most tube tank guns.
I found some 2″x.188″ titanium tubing. Going to bore it and put 1.75″-28 threads in both ends. Making end caps out of 1144. One end will except a valve and the other will have 5/8-18 male threads offset and at a 5 degree angle for a 4500 psi bottle.
I get different numbers from those pressure calculators. Using 60,000 yield strength and 2x safety I get 3800 psi from one and 4300 for the other. I think 60,000 is low for titanium.
I’m making basically a large chamber for a valve to sit in and will not be effected by the small neck of a 4500 psi bottle. Going to try the .308 on higher psi up to maybe 4000 psi. This will be the standard setup for the .451.
Could you use a cut down 400cc bottle ?
Iether just cut off and thread the flat end. Or use just the middle. Yud get a few tubes for yer money then. Or use one as a sacrificial one to pressure test.
Later, Sean.
FR…
GOD, i love that avatar.
😯 😯
here’s another calc.
I just used this online calculator
http://www.rathgibson.com/technical_info/pressure_data/burst_pressure.aspx
Using yield strength gives the pressure at which the tube will permanently deformed and tensile strength gives burst pressure.
What kind of calculations are made to determine pressure ratings?
Thanks. So to get 4500 I would need to go to titanium? How thick of titanium?
A piece of 4130, 2″ diameter and a .120 wall thickness, has permanent deformation at 8400psi, so a safety factor of 2 should let you fill to 4200psi.
Just got to account for the wall thickness at the bottom of the threads.
Dave
What are the big bore guys using for there tubes? They fill to 4600 psi.
it’s safe pressure may be 2500psi . regular steel is only 1800-2000 .
it would be safe at 3000psi id think but depends on the ends . i think 4500 would be over the safe working presure .
more coffee. damn!
Hey LH,
You gotta quit gettin up so early. 😀 😀
try posting in the mods section. you’ll probably get a faster answer there. good luck w/ your project.
Viewing 14 replies - 1 through 14 (of 14 total)
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Hi,
As a rhough estimate you can use the kettle formula. Multiply the smallest inside diameter by the pressure (make shure units are compatible) and divide by 2x the wall thickness. This will give you the stress in the wall. It should not exceed 1/4yield.
Cheers,
marc