1 reply to this topic

[Nagarajan K]

Dear All,

 

I had a query related to Hydro test Pressure.

 

For Example,

 

Suppose my Pump Discharge pipeline has,

 

Operating Pressure = 5 barg,Operating Temperature = 40 Deg C

 

Max. Operating Pressure = 6 barg.

 

Shut-off Pressure say = 8.5 barg,

 

I considered Shut-Off Pressure as my Design Pressure or more then that say 9 barg.

 

So my Design Pressure is 9 barg.

 

Hydrotest Pressure is 1.5 times Design Pressure,i.e, 13.5 barg.

 

Based on this i found that rating selected by me of 150 # is ok.

 

Hydrotest is carried out i found that there is no leaking at any point.

 

But, what if case when i carry out a surge analysis of pipeline with MOV at outlet.

I found that surge pressure is more than hydrotest pressure.

which means there may be leakage or bursting of pipeline or any point of surge line.

 

So is that i shall limit the surge pressure in pipeline below hydrotest pressure or the hydrotest pressure shall be carried out on mechanical design pressure condition of 150 # as per ASME.B31.3 Process Piping

 

What shall i do in that case.Pls guide.

 

 

Regards,

 

Nagarajan K

 

 

 

 

 

[fallah]

Hi,

 

If the surge pressure would be higher than piping design pressure and the number of the surge occurrence and durations fall into the relevant ranges in ASME B31.3; 302.2.4 (f), then the hydrostatic test pressure of such piping system can be considered 1.5 times the design pressure otherwise the surge pressure should be considered as piping design pressure based on which the hydrostatic test pressure should be calculated...