2 replies to this topic

Hi to everyone,

My question is whether NPSH is required for Positive diaplcement pump if so how to calculate the value to find out the result...

what about NPSH ZERO pump which pump comes under this category..it is been quite confusing me to interpret about NPSH details,pl any one intervene in this regards to clarrify my doubts...


Regards,
R.Ramesh

[ankur2061]

Dear Ramesh,

Suggest you go through Section 5.3.2, pages 16 to 19 of ISO 13703:2000 to get a fair idea on the NPSHa calculations for PD (reciprocating) pumps. The particualr example given in ISO 13703:2000 is for reciprocating pumps. Briefly, the factor called acceleration head plays an important role in the determination of NPSHa for reciprocating pumps.

Regards,
Ankur.

[JoeWong]

Dear Ramesh,

Suggest you go through Section 5.3.2, pages 16 to 19 of ISO 13703:2000 to get a fair idea on the NPSHa calculations for PD (reciprocating) pumps. The particualr example given in ISO 13703:2000 is for reciprocating pumps. Briefly, the factor called acceleration head plays an important role in the determination of NPSHa for reciprocating pumps.

Regards,
Ankur.

Latest revision probably is BS EN ISO 13703 "Petroleum and Natural Gas Industries - Design and Installation of Piping Systems on Offshore Production Platforms" CORR 14034: August 13, 2002;
Document Last updated per publisher : 2006-07-27
Reaffirmed/Reapproved date 2006-08-01

May refer to GPSA for acceleration head calculation for Positive Displacement (PD) Pump.

You may noticed that the Acceleration head is very much pump type dependent and it involve a lot of "guess" work (unless you are specialist in PD pump) ...thus in real world application, we specify the NPSHa without acceleration head and pump vendor to select the correct PD pump to suit the application.

NPSH zero pump, probably refer to thus vertical submerge pump or barrel pump (theoretically zero suction pressure drop) which always maintain positive static head and "zero suction pressure drop".

Good luck.