UG-19 (a)

[c8829]

Hello Everyone.

I want to know what is Dependent pressure chamber and Independent pressure chamber?

If anybody can explain or can give any reference..thanks in advance.

 

[abuanaselmasry]

UG-19 is for combination of units. i.e. means when you multi-chamber vessel. i.e. vessel with different sections that is subjected to different operating conditions. If the operating conditions of one vessel is affected by the operating conditions of the other vessel. Then this is dependent chamber. If the vessels are totally isolated from each other, then it is independent chambers.

Examples for dependent:
If you have pressure equalizer connecting the two chambers, then the pressure and temperatures of the 2 vessels are dependent.
One case, I designed Jet-A vessel with outer vessel. However, the outer vessel is only for leak detection and has a leak detector, alarms and controls that will automatically shutdown the vessels. This means the outer vessel will never be pressurized unless otherwise the inside vessel is also pressurized, hence you don't need to design the inside vessel for the external pressure equals to the internal pressure. This is also example of dependent chambers.

Example for independent:
The most common examples are the S/T Heat Exchangers, the heating coils inside a vessel, jackets,.......etc.

Hopefully, I have replied to your question.

Regards,
M.Salaheldin
Static Equipment Mechanical Design Engineer