Pump Inlet/Outlet Nozzle Erosional Effect
Pump Inlet/Outlet Nozzle Erosional Effect
(OP)
I need to select an ANSI pump for a water treatment plant, with the following problem:
According to the Process data we have calculated, the pump differential and flow rate, we have to select a 1x1.5 pump (outlet x inlet nozzle diameters).
However, due to the nature of the fluid we are handling (water + suspended solids) and requirements of our client, our suction line is 3".
Then, in order to interconnect the pump with this pipe, a 3x1.5 reducer is required and the velocity in the reducer and inlet nozzle is too high (22 ft/s).
According to API14E, the velocity should not exceed an erosional limit (in this case 20.25 ft/s).
Also, this reducer introduces a high pressure drop (due to the kinetic and frictional terms).
We have tried to find a pump with bigger inlet and outlet nozzles, without success.
Is there any harm in the pump and/or these fittings if we maintain this or higher velocities?
Regards,
Alberto
According to the Process data we have calculated, the pump differential and flow rate, we have to select a 1x1.5 pump (outlet x inlet nozzle diameters).
However, due to the nature of the fluid we are handling (water + suspended solids) and requirements of our client, our suction line is 3".
Then, in order to interconnect the pump with this pipe, a 3x1.5 reducer is required and the velocity in the reducer and inlet nozzle is too high (22 ft/s).
According to API14E, the velocity should not exceed an erosional limit (in this case 20.25 ft/s).
Also, this reducer introduces a high pressure drop (due to the kinetic and frictional terms).
We have tried to find a pump with bigger inlet and outlet nozzles, without success.
Is there any harm in the pump and/or these fittings if we maintain this or higher velocities?
Regards,
Alberto





RE: Pump Inlet/Outlet Nozzle Erosional Effect
As far as the NPSHR, that would also be included when they do their testing and post the NPHSR figures so I have not included the effect of that reducer in my NPSHA calculations. It's a good question though. One other reason I don't include the reducer is that when I do these calculations, it's in the early stages of engineering and we have no idea what the pump suction nozzle is for a diameter.
RE: Pump Inlet/Outlet Nozzle Erosional Effect
BobPE