SpudFiles

I have I gun made completely from Sch40 steel and I want to know how high up there I can take it safely.In other words how much psi can sch40 steel hold?

i don't think you really have to worry about that. the valve will give out long before the steel. what valve are you using ?

youre gun is only as strong as its weakest part

Well, 1/4" SCH 40 steel pipe can hold over 5kpsi and is rated for at least 2k. 6" SCH 40 steel, on the other hand, has a burst pressure below 2kpsi, and is rated for about 500 psi. Most hardware store variety fittings are malleable iron, rated for 150 psi (although they can be used upwards of 500).

We need a bit more information to give you a good answer here.

I now it is not malleable iron it is Sch40 steel And I am using a ball valve
that is rated to 600 psi I think

then 600psi is the max you can go.

So the steel is rated higher than that

Probably, depending on the diameter of the pipe.

What nominal diameter is the steel?

It is 2in diameter

if it is standard wrought steel pipe sch 40 it has a working burst pressure of 5,185 psi and and a working pressure of 650 psi, you shouldn't exceed the working pressure of the lowest rated parts, in this case that would be your valve. you can get more information here.
http://www.engineeringtoolbox.com/wroug ... _1123.html

great as soon as I find a way Ill start pumping it to 500-550psi which should give it devestating power

bigbob12345 wrote:great as soon as I find a way Ill start pumping it to 500-550psi which should give it devestating power

Heh, not really, since ball valves open so slowly.

I now they do but the valve is very large (1.5in) the chamber is like a foot of 2in and the barrel is 1in. I got a big one because I now ball valves open slowly but if I only open it lets say .25 of the way it will get similar flow to a 1in sprinkler valve and it probably takes a similar time for me to open it .25 of the way as the sprinkler valve would take to open fully so it will get similar opening speed and another thing is there isnt that much air to dump because of the not very big chamber. so I think it will get devestating power

bigbob12345 wrote:I now they do but the valve is very large (1.5in) the chamber is like a foot of 2in and the barrel is 1in. I got a big one because I now ball valves open slowly but if I only open it lets say .25 of the way it will get similar flow to a 1in sprinkler valve and it probably takes a similar time for me to open it .25 of the way as the sprinkler valve would take to open fully so it will get similar opening speed and another thing is there isnt that much air to dump because of the not very big chamber. so I think it will get devestating power

Sprinkler valve would still open faster, just go piston valve, 500psi with a ball valve is probably about the same power as 250psi with a piston valve.

Ive never made a metal piston valve but Ill try it

there is really no telling you first have to find out what guage the metal is then do the math i forgo the formula for psi. length x width x guage=...
then sivided by air consumtion something liek that.