On Jul 26, 2007, at 12:35 AM, Alok Dubey wrote:
> Test Pressure (Hydrostatic Pressure)
> recent edition of ASME Boiler and pressure vessel code derated
> hydrotest pressure from 1.5 to 1.3, more inline with european code.
This is in association with the increase in allowable stresses made a
few years ago. The reduction in proof test pressures is intended to
maintain stress levels and deformation imposed during the hydrotest
at the same level relative to the material ultimate or yield stress,
even though the allowable stress increased. With the new allowables
the maximum service stress increases by a factor of 4/3.5 = 1.14
while the stress during hydrotest decreases by a factor of 1.3/1.5 =
1/1.15.
Christopher Wright P.E. |"They couldn't hit an elephant at chrisw@skypoint.com | this distance" (last words of Gen.
.......................................| John Sedgwick, Spotsylvania1864)
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