Pressure vessel software compress internal pressure value?

The 0.4kg/cm2 pressure means above atmospheric pressure .Since most gage always read above atmospheric pressure it is enough to design for 0.4kg/cm2 both for internal and external pressure

Nelson

we are given with 0.4 kg/cm2 absolute pressure.while absolute value of atm pressure is 0 kg/cm2 (14.7 psi).Please confirm that while designing we will put internal value as .4 kg/cm2 and external value as 0 kg/cm2. Actually I am cofusing with absolute and gauge pressure values...If 0.4 kg/cm2 is gauge pressure then what will be the atm pressure and if 0.4 kg/cm2 is absolute pressure then what will be atmp pressure.please explain.

Please join some Engineering school instead of expecting CR4 forum to teach you.

0 kg/cm2 in not 14.7 psi. It is 0 psi.

You are totally confused and need school to teach you.

Absolute pressure = Gauge pressure + 14.69

or you can add 1.0 kg to the gauge Kg/Cm2 pressure to equal Absolute pressure in Kg/ Cm squared.

I hope it helps.

Regards;

Nadeem Butt

06132008

Absolute pressure=gage pressure+atmospheric pressure If atmospheric pressure equal to 0.4 then gage pressure equals -0.6kg/cm2 ie negative pressure -vaccuam- so when u design external vessel design it for 1.6kg/cm2 If its internal 0.6kf/cm2 to be on the safe side take it as 1kg/cm2 Nelson

Greetings!

Please keep in mind when executing your calculations that the second variable in the equation for solving absolute pressure varies and is dependent upon the altitude wherein the device is located. The relationship is inverse ie: the higher the altitude, the lower the value. This may not be critical in your instance, but it could be and if so, the resultant oucome might not be acceptable nor safe.

Not knowing the details of your application makes it somewhat difficult to render a competent answer. However that being said; usually enclosed (inside) pressure measurements are based upon guage due to the fact the fluid pressure is being controlled by a design process that is independent of atmospheric pressure conditions. Keep in mind that ambient fluid density (required knowledge for safe design application) is dependent upon humidity (moisture content), suspended contaminents (dust,oil,etc), altitude, and temperature all of which affect external pressure design calculations. All of these can be and should be measured before attempting design or you must adopt "worst-case" conditions.

Hope this helps you out. I would suggest that you find a competent, experienced person/company with mechanical engineering background to consult with and you should consider developing a working relationship with such person/firm so that they can mentor you and answer your questions.

Good luck!