Design Pressure
Design Pressure
(OP)
How do I decide pressure size when design pressure on data sheet is described as Full Water only.
Do I have to decide pressure one by one according to the elevation of component for getting pressure head?
Is it usual method?
Do I have to decide pressure one by one according to the elevation of component for getting pressure head?
Is it usual method?





RE: Design Pressure
RE: Design Pressure
Regards
RE: Design Pressure
Even I got more knowledge about vacuum condition.
RE: Design Pressure
If the item in question is not just enormous, fittings subject to hydrostatic pressure only would normally be sized for some nominal pressure class- say, 150#- regardless of the actual pressure, which might be much lower.
RE: Design Pressure
I sometime found "design pressure" is stated as "Full Water" and "Atmospheric".
But I treated both different, when "Full Water", I do it like my question above. When "Atmosheric", I put design presure as zero.
Is it correct? Or both are actually the same.
RE: Design Pressure
Full of water means that the height of water column is acting like internal pressure on the wall and bottom junction, (P= rho x g x H = Water density kg/m3 x 9.81 m/s2 x H meters of water height). In addition, the vessel or tank may have some vapour or other gas pressure above the liquid, in which case is called "vapour space pressure" and has to be added to the "Full of Water" pressure, to establish the wall thickness calculation pressure / design pressure. If there is no additional "vapour pressure", that means the vessel or tank is vented to the atmosphere and then you call it "Atmospheric". However, the design pressure is still not zero, but water column only, without additional vapour pressure.
Cheers,
RE: Design Pressure
Be careful with the descriptive atmospheric.
Atmospheric means that you design the "T" joint, bottom of tank, based on the level when full of the product stored in the tank at atmospheric pressure based on the density of same.
All our storage tanks use the minimum value for density of 1 with others designed using the density of the product being stored. We have numerous tanks that store material with a density of 1.35 and several H2SO4 tanks using a density of 1.85