# Vacuum chamber thickness design

1. Feb 15, 2014

### satish19183

Vacuum pressure for design of pipe

Dear experts,
I have a line pipe wich internal design pressure is 98 bar,dia is 36: thickness is 13 mm,length is 12 mtr. I want to know that how much vacuum pressure sustain by this line pipe?

Regards,
Satish patel,

2. Feb 15, 2014

### satish19183

I want to design 36" OD,12 mtr long vacuum chamber with 1 mbar vacuum pressure.
Request to gove sample calculation for find out thickness of the same.

3. Feb 15, 2014

### Baluncore

A vacuum in the atmosphere on the surface of the Earth cannot be greater than one bar, so maybe your question is …
If the pipe is rated for an internal pressure of 98 bar, then when it has a vacuum inside, how much external pressure can it withstand before it collapses?

4. Feb 15, 2014

### Baluncore

Does the chamber contain anything that contacts the wall ?
What temperature range must it withstand ?

The wall only needs to withstand one atmosphere = 14.5 psi.

Can you support a very thin wall with an external structure that will maintain the surface curvature and therefore prevent collapse of the surface.

Consider also avoiding metal by using a plywood inner surface with a plastic film shrunk on to the outside.
Surface stability requires thickness, it could be laminated with a foam core.

5. Feb 15, 2014

### Staff: Mentor

Last edited: Feb 15, 2014
6. Feb 15, 2014

### Staff: Mentor

Welcome to the PF.

(I've merged your two threads on what looks to be the same type of question)

It is a bit worrisome that you are asking questions like this here on an Internet forum. What experience do you have with pressure vessels? What are you working on? What is your educational background?

We have rules here at the PF concerning dangerous activities. We are able to help professionals with questions about pressure vessels. But we would be reluctant to help an amateur experiment with high pressure vessels (or vacuum chambers) where a failure of the vessel could cause people to get hurt.

7. Feb 15, 2014

### Baluncore

So the diameter is not 36mm but 36”. Is that right?

Before we can help you with this question we need to know;
What is the purpose of the chamber?
What temperature range must it withstand ?
Does the chamber contain anything that contacts the wall ?

8. Feb 15, 2014

### Chronos

The wall thickness is questionable. It appears it will probably deform, but, not fail.