Pump Curve
Pump Curve
(OP)
Hello,
Is dead head the same as shut off head?
Paula
Is dead head the same as shut off head?
Paula
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RE: Pump Curve
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RE: Pump Curve
I am talking about pumps!
Can you explain what dead head is?
I have to size a pump for 465 gpgm @ 200 psi. If I look at the pump curve I can choose the right pump model and size but always need to keep in mind dead head. Can you explain dead head?
Thanks,
Paula
RE: Pump Curve
Very briefly, pump dead head/shutoff head is where all power is delivered to no net flow out of the pump, so all power is being input only to the fluid contained within the pump itself. The high pressure fluid spills back past the impeller clearance into the intake area again. Look at the pump's efficiency at zero flow and you see it is very low, signifying that almost all the energy spent is being converted into heating up that little bit of trapped fluid. It will usually overheat quite rapidly, build up temperature and boil the fluid, dry seals and bearings.... and pretty soon you're smoked. Continued operation below 20% of BEP flow will usually start heating up the fluid, below 10% you will usually get some pretty fast temperature buildups to damaging levels. So startup flows should start at a minimum of 20% of pump BEP and build up as fast as possible to say around 40% and then continue up to 60% minimum as per the suggested operating range for API pumps you can see on thread, thread407-186675: Operating region for pumps according to API: Operating region for pumps according to API
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RE: Pump Curve
Try to select a pump curve that intersects the system curve close to the best efficiency point, aka BEP. This is the simple answer to your question.
RE: Pump Curve
RE: Pump Curve
"If you're talking about pumps, it is."
"Well I have known some other types."
Pity we don't have a humour forum - this would rate well.
RE: Pump Curve
Engineering isn't a very humorous subject, so I have to make the most of the few opportunities that do come along.
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RE: Pump Curve
Hey,thanks guys for all your replies. More humor the better!
Engineering can be at the very least dull at times.
Paula