vaccum adequacy check inpipelines

[parthanml]

To check whether the pipe can withstand external pressure due to the loads like earth load, A test called vaccum adequacy check is being done. Somebody please explain this check.

 

[BigInch]

When the external pressure on an object is greater than the internal pressure, there may be danger of collapse. Google "USS Thresher".

With normal Diameter to Wall_thickness ratios of most commercial steel pipe sizes that can be used for high pressure applications, this is not a problem for onshore pipeline installations and seldom becomes a problem offshore, until water depths get to be around 100 m or more.

With the number of deep water installations these days, you see the calculation much more than before and all the onshore pipeline client guys (with no experience) think they're on to something and it is a BIG PROBLEM for them too. They want to make it a big problem for everybody else too. Not so. Usually a BIG waste of time, unless you're burying your pipeline VERY deep or laying rice noodles.

What would you be doing, if you knew that you could not fail?

 

[parthanml]

Can you explain me this check ?

 

[BigInch]

http://www.roscoemoss.com/waterwell-calculations.html

What would you be doing, if you knew that you could not fail?

 

[parthanml]

Thanks BigInch
At the end we will be getting a collapse pressure value .
How to check whether our design is safe with that collapse pressure value ?

 

[btrueblood]

"How to check whether our design is safe with that collapse pressure value ? "

Make sure the external pressure on your pipe is everywhere less than that value, preferrably by a comfortable "margin of safety". You might need a soils/geotechnical engineer to help you.