4 replies to this topic

[Sherif Morsi]

Hi,

 

I am looking for a reference to determine the maximum nozzle loads for a small diaphragm pump. API 675 doesn't provide any guidance for that. Any help regarding this? Whether industry standard or text books?

 

Regards,

Sherif

[Art Montemayor]

I may be wrong, but I don't think you are allowed any nozzle loads on a pump.  This should be confirmed or identified by calling or writing the diaphragm pump manufacturer and requesting this information.

 

I never allow for any nozzle loads on centrifugal pump flanges and I consider a diaphragm pump more sensitive to external loads than a centrifugal pump.

[fallah]

Sherif,

 

Art is completely right; the only one who is authorized to submit the allowable nozzle loads for a pump, either centrifugal or diaphragm type, is relevant vendor...

[Kriss]

Dear Art, Dear Fallah,

 

You explanation is correct. I will explain how we deal this issue as a Rotating equipment engineer.

 

It is the vendor who provides the allowable nozzle load. Many times allowable nozzle loads  are too less considered by vendor. upstream piping need more support. So normally we ask vendor during bidding stage that the allowable nozzle load required is at least 2 times API 610loads in case of centrifugal pumps.

 

For Reciprocating pumps, we don't ask vendor to provide sufficient nozzle loads because there is a suction pulsation dampner provided at suction, which is sized in such a way that it can withstand to the upstream pulsations.

 

krishna

[Sherif Morsi]

All,

 

Thank you for the valuable feedback. Of course, nozzle loads should be provided by the vendor; for centrifugal pumps, we have some guidelines to follow which is not the case for PD pumps. 

 

It should be noted that there is no suction dampener and the mechanical team here asked the vendor to submit the nozzle loads and it will be covered from our side (piping and support design). I am not quite happy with it but it seems that's our only option so far. I would be glad if you have any other suggestions and/or guide me to some literature that would help.