Testing individual pump performance when pump is in parallel?
Testing individual pump performance when pump is in parallel?
(OP)
Hello,
I have been in heated discussion with a vendor who recently tested overhauled and tested a boiler feedpump for me. I attempted to explain that you can not measure the performance of an individual pump performance (head and flow) when the pump in parallel. Because if the discharge head of one pump is higher then the other, the stronger pump's discharge head will be what is actually measuring. Even if the dishcharge pressure is measured after before the the discharge lines combine to a common header. I certaint this to is true, however I cannot remember what physics law this falls under. Can any one help.
I have been in heated discussion with a vendor who recently tested overhauled and tested a boiler feedpump for me. I attempted to explain that you can not measure the performance of an individual pump performance (head and flow) when the pump in parallel. Because if the discharge head of one pump is higher then the other, the stronger pump's discharge head will be what is actually measuring. Even if the dishcharge pressure is measured after before the the discharge lines combine to a common header. I certaint this to is true, however I cannot remember what physics law this falls under. Can any one help.





RE: Testing individual pump performance when pump is in parallel?
RE: Testing individual pump performance when pump is in parallel?
Johnny Pellin
RE: Testing individual pump performance when pump is in parallel?
RE: Testing individual pump performance when pump is in parallel?
Johnny Pellin
RE: Testing individual pump performance when pump is in parallel?
And then re-built one of them and re-tested you could infer how much it changed.
But by nature your second test will not be at the same flow as the first. Combined with the fact that you don't really know the pump curve for either pump. No, you can't measure much.
= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Testing individual pump performance when pump is in parallel?
RE: Testing individual pump performance when pump is in parallel?
http:
From the hydraulics of flow and differential head of each pump, you know the output power of the pump; From the electrical power consumed, you know the power input.
Input_power - Output_power - frictional & conversion losses ==0
http://virtualpipeline.spaces.msn.com
RE: Testing individual pump performance when pump is in parallel?
RE: Testing individual pump performance when pump is in parallel?
Then I would disconnect it from the discharge header, simulate the same discharge pressure as that of parallel arrangement and then read the flow readings.
As this is a boiler feed pump, you should have approximate idea about the flowrates (by boiler capacity, by fuel consumption etc. etc). Now check whether the test pump capacity is nearer to 50% of the total flowrate and that is all.