Thermal contraction / vacuum rating 1

[ewcrabtree]

I have a section of small diameter (3/8") tubing that will be isolated between two closed valves, capturing hot water between the valves. When the water drops to ambient temperature, density changes will create a vacuum of an estimated 1 to 1.5 psia between the valves (Reverse of thermal expansion problem).

Any guidance on determining the wall thickness required for obtaining a given vacuum rating would be appreciated.

 

[jte]

ewcrabtree-

Internal pressure will govern your design. A quick check of a Section VIII-1 design approach with carbon steel indicates a required thickness of 0.004" for full vacuum - 10 times your requirement. I'll just bet that your tube is thicker than 0.004".

jt

 

[DSB123]

ewcrabtree,
jte's got the answer. With such a small diameter it will be able to "eat" full vacuum.

 

[ewcrabtree]

Thanks y'all. I appreciate the help!

The wall thickness is, indeed, greateer than 0.004" -- 0.065" for 16 BWG SS tubing.