Thread: Pump Head
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David Hansen David Hansen is offline
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Default Pump Head

On Mon, 11 Feb 2008 07:01:52 -0800 (PST) someone who may be Garry
wrote this:-

Im struggling with the pump term "Pump Head". when used in central
heating application.


It has nothing to do with the height of anything. That is the static
head. The pump head is a dynamic head which only exists when the
pump is running.

Imagine a heating system where all the pipes are horizontal, other
than those to the F&E tank. The heating pipes would then be under
the static head from the F&E tank. Assume that the pipes from the
F&E tank are connected to the right place, the suction side of the
pump. When the pump is turned on it will develop a dynamic head at
the outlet. The pressure in the pipe at this point will be the sum
of the static and dynamic heads.

As the water flows round the pipes some of the dynamic head will be
"used up" overcoming the resistances in the pipes and the various
fittings which form part of the pipes. By the inlet to the pump this
dynamic head will be reduced to zero and the pipes will just be
under the static head.

How much water the pump can push around a particular heating system
depends on the dynamic head it can create and the resistance the
pipes provide. Pipes are generally sized so that they are as small
as possible to carry the necessary amount of heat without the water
velocity rising so high that the system would be too noisy.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
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