Pipe Pressure

reference:

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American Welding Society www.aws.org/w/a/

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You can find here

http://www.tube-mac.com/pdf/tubemac_section_a.pdf

and similar sites.

Success to you!

HI. Well, normally it's not the way the design goes, you normally choose a required ID and oper. pressure and then choose an OD from a material that's cheap and easy to manufacture. It seems that you're gonna build an hydraulic actuator, am I right? I'm gonna tell you the formula anyway.;

In any book you're gonna find the furmulae for pipe dimensioning. The simpler is:

Sadm = P x r / t for pipes (tangencial stress), and

Sadm = P x r /2t for pipe end covers (longitudinal stress). In this case, a vector combination is required to obtain the total stress.

where, in si:

Sadm = acceptable tension in material [Pa]

P = internal pressure [Pa]

r = outter radius (the more loaded point of the tube). It's because this simple formula is intended to give you values for thin wall tubes, what is not your case. Anyway, use it as an initial approximation. You will be forced to enter a good safety margin anyway...

t = tube thickness.

Using consistent units in this formula, you'll be able to obtain the stress required for your application geometry. DOn't forget to dimension to twice the operational pressure, for safety, stiffness, and because that's the way it should be if you refer to any standard.

For the numbers you posted, the stress will be

6000 psi approx 41,37 MPa

2 in = ,0508 m

1 in = ,0254 m

Sadm = 82.74 MPa

If you consider the double, You'll have approx. 165 MPa min yeld stress in your material. For these numbers, a low carbon steel in a cold drawn condition (Sy=approx. 200 - 250 MPa) will sufice. Note that low carbon steel normalized (Sy=125 MPa approx.) will not be enough if you consider the safety margin. You have a lot of material in that 1" wall X 1" ID

Also: If it's an actuator, don't forget to add the mechanical stresses in work with the internal pressure values.

Thanks a Lot. I got a use full Information from Cr4 people.

a Pipe with a 2" OD, and 1" ID only has a 1/2" wall

Very well observed. I think I missed it thinking about 1" wall.

So, you're gonna need 160 MPA admissible, 320 MPa max stress in material.

Did you consider the remaining mechanical loads in it?

You still may need a cold drawn steel around 300 MPa yeld strengh, or, if the remaining mecahnical loads are to be considered, go for a low alloy steel. I think an SAE 1045 would do well.