"Ignoramus2605" wrote in message
...
On Tue, 08 Mar 2005 20:01:39 -0500, Bob Engelhardt
wrote:
Ignoramus17028 wrote:
...

Bob, I am thoroughly confused as to just what the bypass valve is
supposed to be doing. What is its job?


Pressure washers are positive displacement pumps. This means that they
displace a fixed volume of water per stroke. If the pump were dead headed,
the pump/motor would stall or worse, break into pieces. When the spray
valve is open, the bypass valve is closed allowing all of the water that is
being pumped to go thru the nozzle. When the spray valve is closed, the
bypass valve opens recirculating the discharge side of the pump to the inlet
of the pump. Some setups may vary but this is the most common I've seen.
Basically, the bypass valve is a relief valve. It is important to not let
the machine run too long without spraying to avoid overheating the pump.
Nothing to get really paranoid about, just don't leave it running during a
smoke break.

Shawn