CHoff07
Mechanical
- Aug 14, 2012
- 15
Is it ok to have an eccentric reducer right at the inlet of a Sundyne Pump?
I have an existing installation of a Sundyne pump (LMV-311 3"x2") The suction pipe is 6" diameter schedule 80 from the vessel to about 4 feet from the pump, then a 6x3 reducer is used to get down to the pump's suction flange size.
We are increasing the flow to this pump service(and changing the pump from LMV-311 to LMV-341).
Rated flow is 369 gpm
SG:0.626
Viscosity: 0.17 cP
Temp: 305F
Based on a simple line loss calculator and using the 4' of 3" pipe I have ~.38 psi pressure drop which comes to ~1.4 feet of NPSH loss!
I need every foot I can get.
In order to reduce the suction line losses I want to remove this 4 foot section of pipe and replace it with 6" and the put the reducer as close to the pump suction flange as possible.
Is this ok to do on a Sundyne. The 6" suction pipe will have more than 10 pipe diameters of straight run before the reducer (actually 5.9' of straight run 6" pipe).
Side note: the new pump will utilize an inducer (we have a spillback to keep the flow through the pump constant) and we plan to raise the minimum liquid level on the vessel to improve NPSHa. Aside from that I have no other options to increase NPSHa (Customer will not run these pumps in parallel).
I have an existing installation of a Sundyne pump (LMV-311 3"x2") The suction pipe is 6" diameter schedule 80 from the vessel to about 4 feet from the pump, then a 6x3 reducer is used to get down to the pump's suction flange size.
We are increasing the flow to this pump service(and changing the pump from LMV-311 to LMV-341).
Rated flow is 369 gpm
SG:0.626
Viscosity: 0.17 cP
Temp: 305F
Based on a simple line loss calculator and using the 4' of 3" pipe I have ~.38 psi pressure drop which comes to ~1.4 feet of NPSH loss!
I need every foot I can get.
In order to reduce the suction line losses I want to remove this 4 foot section of pipe and replace it with 6" and the put the reducer as close to the pump suction flange as possible.
Is this ok to do on a Sundyne. The 6" suction pipe will have more than 10 pipe diameters of straight run before the reducer (actually 5.9' of straight run 6" pipe).
Side note: the new pump will utilize an inducer (we have a spillback to keep the flow through the pump constant) and we plan to raise the minimum liquid level on the vessel to improve NPSHa. Aside from that I have no other options to increase NPSHa (Customer will not run these pumps in parallel).
