Nozzle Load table in API 610 1

[hyunbum11128]

Hello,

Can anyone tell me how values in Nozzle Load values are calculated in API 610?

Thank You

James

 

[1gibson]

No, but see annex F for guidance (only applicable to certain pump types!)

 

[hyunbum11128]

Hi,

I know Annex F, but i would like to figure out how Fx, Fy, Fz, Mx, My, Mz are calculated.

Thank You

 

[GPRnD]

You mean how the API 610 committee decided on what values to put in the table ?

If so that might take a bit of digging, but I know several people on the committee so I'm sure one of them has the answer.

 

[hyunbum11128]

Hi GPRnd,

Do you think there is a way for you to see how they might have decided those values?

Thank You

 

[GPRnD]

I'll ask and see what response I get. If I get something printable and coherent I'll post it

 

[hyunbum11128]

Thank you for the help!

 

[hyunbum11128]

any update?

 

[Pushkar4Mechanical]

criteria used for nozzle load is based on movement( basically .0050 to .0100 depending on the size of the pump.) over the coupling end of shaft due to forces Fx, Fy, Fz, Fr .
These forces are taken into consideration for checking movement of the entire assembly when load is put on,Movement of the feet of the casing relative to the baseplate due to the friction force between the two,movement of the bearing housing relative to the base plate,Internal movements causing rubbing of the impeller against the casing,movement of the base plate surface relative to the driver shaft.

 

[hyunbum11128]

Yes, I already know that. I was just wondering how those values are calculated.

 

[Pushkar4Mechanical]

Applicable for API pumps. Qualifying nozzle loads and movements for imposed piping loads using CAESAR.The maximum size covered is up to 16',selecting allowable based on nozzle size and rating for150# are accessible,see table-5 of API-610,And choose for the orientation of nozzle inline with your pump. As the rating increases you have to get the data from vendor beyond specified class in table-5 and annex-F, for qualifying in caesar.

 

[1gibson]

You are assuming that the values are calculated. In reality, the values are established based on field experience, and risk tolerance, of pump vendors.

If the deflection due to nozzle loads puts the motor, seal, or other rotating element out of alignment, there will be problems. Pump vendor will be on the hook to warranty the problems. Pump vendor tries to understand and/or reduce this risk, by limiting allowable nozzle loads to known safe values.

Especially for large nozzles, stress can be quite low but still lead to big deflections (often causing piping designers to ask if the pump is made out of tin foil.) Linear extrapolation of the API table should not be expected (this argument usually follows the tin foil comment.)