Test Pressure Assessment 1

[FIF99]

Hi,

Anybody familiar with assessment of hydrostatic test pressures of Piping Systems?
Design code is EN 13480 - 3, so test pressure to be assessed as per EN 13480 - 5. Considering equotion 9.3.2-2 we need to know whether the cold design pressure, or the reduced hot design pressure applies in this formula.

Thanks in advance.

Regards,
FKE

 

[Raaden]

The formulas 9.3.2-2 & 9.3.2-3 are directly derived from the following quote from the PED 97/23/EC:

"For pressure vessels, the hydrostatic test pressure referred to in 3.2.2 must be no less than:

that corresponding to the maximum loading to which the pressure equipment may be subject in service taking into account its maximum allowable pressure and its maximum allowable temperature, multiplied by the coefficient 1,25, or

the maximum allowable pressure multiplied by the coefficient 1,43, whichever is the greater."

So to answer our question; The design pressure specified is the hot design pressure. If you multiply this with your your max allowed stress at test temp (room temp.) and divide it with your max allowed stress at the design temp. then you will probably end up with your cold design pressure.
You can find a similar formula in ASME section VIII, Div.1 - UG-99 (b), but they use 1.3 as a multiplier instead of 1.25

 

[FIF99]

Raaden,

Thanks a lot and I fully agree with your notes.