On Mon, 06 Jun 2005 03:47:44 GMT, Brian Whatcott wrote:
In this case, because the start pulse seems to come back twice as high
- assume that the far end is terminated in a high impedence.
So the far end pipework narrows or the far end bladder is too stiff.
THERE's a new insight!

Only looks that way. Perhaps because you appear to have skipped much
of the thread... The far end pipe does narrow, but changing it may no
appreciable difference. The far end bladder is not too stiff, because
then the pressure would only increase, not be a spike.

The pressure spike it high, not because of a bounce back, but because
water is incompressible, water has mass hence inertia, and pipes have
friction. The pump starts, wants to move water, water does not start to
move instantly, so the pressure seen near to the pump has a high spike
that rapidly reduces as the water starts to move.

Not rocket science, well understood in well pump systems for many years.
That is why the proper installation puts the pressure switch near the
pressure tank. (My system, for example, has 150-200ft between pump and
tank, and less than 3ft between tank and pressure switch.)

sdb

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