Hight Temp & High Suction P - effect on performance? End suction centrifugal
Hight Temp & High Suction P - effect on performance? End suction centrifugal
(OP)
Just looking for thoughts based on experience.
We have an end suction ANSI pump, 2x3-8, if that matters. On the test bench, we get performance close to the factory curve, using cold water (15C), suction pressure 4psig.
In the field, the exact same pump with the exact same clearance (nothing was changed), running with 145psig suction pressure and 355F water, the performance is approx. 10% less (as in, let's say at 140 gpm flow rate, on the bench we get 320 ft head; in the field with hot water / high suction press, we get 293 ft).
Obviously, these numbers are adjusted for the SG of the hot water, but is there some other reason that, with the same speed, same impeller, same clearance, and same flow rate, we would get lower head? One would almost think you'd get better performance at the higher temp, as the clearance would tighten up when the pump heated up.
Scratching my head, wondering if it's time for a drink yet.
We have an end suction ANSI pump, 2x3-8, if that matters. On the test bench, we get performance close to the factory curve, using cold water (15C), suction pressure 4psig.
In the field, the exact same pump with the exact same clearance (nothing was changed), running with 145psig suction pressure and 355F water, the performance is approx. 10% less (as in, let's say at 140 gpm flow rate, on the bench we get 320 ft head; in the field with hot water / high suction press, we get 293 ft).
Obviously, these numbers are adjusted for the SG of the hot water, but is there some other reason that, with the same speed, same impeller, same clearance, and same flow rate, we would get lower head? One would almost think you'd get better performance at the higher temp, as the clearance would tighten up when the pump heated up.
Scratching my head, wondering if it's time for a drink yet.





RE: Hight Temp & High Suction P - effect on performance? End suction centrifugal
RE: Hight Temp & High Suction P - effect on performance? End suction centrifugal
Not really my area -- but,
Same motor?, if different motor did you check speed?
How about viscosity changes?
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Hight Temp & High Suction P - effect on performance? End suction centrifugal
Those are the items that occur to me.
Johnny Pellin
RE: Hight Temp & High Suction P - effect on performance? End suction centrifugal
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Hight Temp & High Suction P - effect on performance? End suction centrifugal
And the thrust issue is worth checking, it's a brand new pump, but still, will dig into it.
that's why I thought i'd throw it out here, to get the experts thoughts.
As to the motor, the speeds were verified with a strobe, and the test bench set at the speed measured in the field, so that's not the issue.
thanks for the ideas
RE: Hight Temp & High Suction P - effect on performance? End suction centrifugal
RE: Hight Temp & High Suction P - effect on performance? End suction centrifugal
Without any details on the system is it possible that flow metering and pressure measurement etc is inaccurate at 355F and the pump is actually going okay.
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"