Two stage pumps sort of shift gears, so to speak, in that when they
reach a predetermined pressure, due to load imparted on the log for
instance, they drop in GPM but go up in pressure, and remain at higher
pressure and lower flow until resistence drops, then pump cycles back
to a higher flow rate with lower pressures, sort of like a automatic
tranny downshifting.........its all done by the settings made
internally in the pump.

They allow a smaller HP motor to be used in a lot of cases to provide
the same rating, and saves a lot of wear and tear on hydraulics in
general.



On Thu, 17 Feb 2005 13:48:56 +0800, OldNick
wrote:

===On Tue, 15 Feb 2005 03:02:28 GMT, (Roy) vaguely
===proposed a theory
===......and in reply I say!:
===
=== remove ns from my header address to reply via email
===
===
===GPM is how much the time it takes to cycle due to flow in an unloaded
===operation. More load, GPM is going to drop, and pressure will
===increase..
===
===Is this something to do witht eh two-stage pumps? Hydro pumps should
===deliver constant flow, at any pressure


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diagnosis. but, can try email put "help sick fish" in subject. Get your fish at Dandy Orandas
Dandy Orandas Dandy Orandas........you guys got that DANDY ORANDAS