Design Vacuum Pressure

About 12in/300mm of water column below atmospheric, or the difference between a bright summer's day and a late autumn squall.

Dear Mr.bhalachandra,

30 mbar = 0.0295 Kg/cm^2 which has a saturation temp. of 24.10 Deg.C Pl. refer the Steam Table. This is equal to 760 - 21.7 = 739 MM Vaccuum or 29.09 Inches Vac.

Full Vac. possible is 760 MM or 29.92 Inches of Hg. Column, at MEAN SEA LEVEL.

Conversion Factor between bar and Kg/cm^2 is 1 bar = 1000 mbar = 0.9838 Kg/cm^2. and 1 Atmosphere = 1.03 Kg/cm^2 = 760 MM Hg. Column = 14.696 psi. = 29.92 Inches of Hg.Column i.e Mercury Column = 34 Feet of Water column, at Mean Sea Level.

DHAYANANDHAN.S

...except that the original poster's minus sign in front of the 30mBar suggests that the figure is already gauge pressure.

If the vessel is to be designed for full vacuum, then the specification sheet needs to be explicit about it.

I agree with the Slacker....

The vessel design datasheet for the vessel should require a "full vacuum" design.......even though the process will never see it.

The reason for this choice is that according the vessel design codes ( ASME etc) it is much simpler to design and reinforce (if necessary) for full vacuum than to play complex design games with partial vacuum.

-0.435113213 pounds per square inch

-30mbar means 0.03 bar means 22.5mmHg that already is the gauge pressure. Absolute pressure (can never be negative) calculate via 760 - 22.5 = 737.5mmHg (within your vessel)