Why you should never dead-head a circulator

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Why you should never dead-head a circulator

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Charlie from wmass

I very much enjoyed the article well written and informative as always. But every time I read the word pump I had to chuckle.

Nimrod66

This may be a stupid question, but in the formula for the 40 HP circulator, 20 BHP is used. How did 40 HP become 20 BHP? It looks like it has something to do with "(at shut off)". I don't know how to figure the difference.

DanHolohan

It’s Break Horse Power. We get that from the pump curve.

Hammer

I think your spell check corrected your 'brake' to 'break', Dan....lol. As I recall my mech eng classes, it was called 'brake' horsepower b/c they applied a Prony brake to the end of the crankshaft on an engine to load up the engine and measure the output torque and then convert it to net output hp at the end of the shaft.

Charlie from wmass

A pony brake.

Nimrod66

If I understand correctly, HP typically includes losses created before the point of use, for instance within a transmission or gearbox, whereas BHP is measured at the output shaft of the engine or motor.

Hammer

Nimrod66 said:

If I understand correctly, HP typically includes losses created before the point of use, for instance within a transmission or gearbox, whereas BHP is measured at the output shaft of the engine or motor.

That is exactly correct.

Hammer

Charlie from wmass said:

A pony brake.

Actually, no, I believe it is "Prony" as in, Gaspard de Prony.......the guy that came up w/ the idea to apply a load to measure ouput torque. I believe it was the precursor to the dynamometer. When James Watt was coming up w/ the concept of "horsepower" he compared the lifting power of both horses and ponies, so maybe that's what you were thinking.

Charlie from wmass

Since I am from Massachusetts I will use the excuse we don't have Rs up here. I can take the rest of the day off I have learned something new thank you.