HELP WITH HOW TO CALCULATE THE THEORITICAL VALUES FOR PLOTTING THE PRESURE VOLUME PLOT FOR HYDROTEST
HELP WITH HOW TO CALCULATE THE THEORITICAL VALUES FOR PLOTTING THE PRESURE VOLUME PLOT FOR HYDROTEST
(OP)
Gents,
Am preparing for a hydrotesting job.
I need a formular to determine values for pressure and volume i.e for plotting theoritical DV/DP, which will then be used to compare with the field values to determine volume of entrained air in the pipeline during the hydrotest.
Having a bit of a challenge in the application this formular
DV/DP = V*[ (D/(E*t)(1-V2) +C]
Where V = Volume (gallons)
D = OD inches
t= wall thickness inches
V poisson ratio of steel pipe = 0.3
C =Compressibility of test media (inch3/inch3/psi)
Dont know what THE VALUE OF COMPRESSIBILITY OF WATER in Inch3/inch3/psi
Will appreciate any advise or alternative way around this .
many thanks
Am preparing for a hydrotesting job.
I need a formular to determine values for pressure and volume i.e for plotting theoritical DV/DP, which will then be used to compare with the field values to determine volume of entrained air in the pipeline during the hydrotest.
Having a bit of a challenge in the application this formular
DV/DP = V*[ (D/(E*t)(1-V2) +C]
Where V = Volume (gallons)
D = OD inches
t= wall thickness inches
V poisson ratio of steel pipe = 0.3
C =Compressibility of test media (inch3/inch3/psi)
Dont know what THE VALUE OF COMPRESSIBILITY OF WATER in Inch3/inch3/psi
Will appreciate any advise or alternative way around this .
many thanks





RE: HELP WITH HOW TO CALCULATE THE THEORITICAL VALUES FOR PLOTTING THE PRESURE VOLUME PLOT FOR HYDROTEST
See FAQ378-1339: Pressure increase due to thermal expansion of a trapped liquid , where you can take αfΔT=ΔV/V and αvΔT=0. There you'll find also the compressibility of water.
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RE: HELP WITH HOW TO CALCULATE THE THEORITICAL VALUES FOR PLOTTING THE PRESURE VOLUME PLOT FOR HYDROTEST
RE: HELP WITH HOW TO CALCULATE THE THEORITICAL VALUES FOR PLOTTING THE PRESURE VOLUME PLOT FOR HYDROTEST
There are two V s in this formular. First one is Volume (big V) second one is supposed to be small v squared for poisson ratio. i wrote that as V2.
Also there is a clossing parenthesis missing. The correct representation is as shown below. Sorry for the mix up.
DV/DP = V * [ (D/(E*t)(1 - v squared)) +C]
Where V = Volume (gallons)
D = OD inches
t= wall thickness in inches
v= poisson ratio of steel pipe = 0.3
C =Compressibility of test media (inch3/inch3/psi) (inch3 = cubic inch)