Water pump

[Pete Masterson]

Sounds like you have a pump that's a bit out-of-date.

Several folks replaced their house water pump(s) with a ShurFlow
variable speed pump, with up to 5.9 gallons per minute delivery. It
pressurizes the system to about 65 psi. This pump goes right into the
water line and does not require an expansion tank. The pump kicks in
on demand and pumps at a rate to keep up with the water flow up (by
sensing the pressure) to it's maximum capacity. The only drawback is
that it may make some Microphor toilets not act right*. (In my coach,
the Microphor toilet has a maximum 50 psi water pressure requirement.
I plan to install a pressure limiter on the water line to the toilet
when I get around to it.)

* The Microphor will not flush properly when the water pressure is
above spec. The work around is to flip open the sink faucet and
"Instantaneously" hit the flush lever. The pump always delays for a
microsecond, so the pressure drops sufficiently for the toilet to
flush before the pressure goes back up.

The more usual pump system pressurizes to about 45 psi with a pump
and expansion tank. When you open a faucet, the initial pressure is
provided by the expansion tank and once it starts to drop, the pump
cycles on to return the pressure to 45 psi. These pumps are usually
limited to 3 or 4 gpm. Originally, my coach had two pumps, plumbed in
parallel. You could run one, the other, or both. Pressure was still
set for 45 psi so it didn't actually make much difference -- we
rarely had demand that exceeded the gpm rating of one pump.

Aside from the Microphor toilet thing, the variable speed pumps only
other downside is that it pumps out the water faster than the old
pump -- so if you're spending a lot of time boondocking, you may not
want it. Showers, however, are _much_ more satisfying with the
variable speed pump.

I searched the Internet for the ShurFlo pump ... It's been discussed
on this list (or the other WL list), so check the archives.

Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
El Sobrante CA
aeonix1@...



On Aug 26, 2007, at 1:27 PM, Ryan Wright wrote:

> Where can I buy a replacement water pump and/or pump rebuild kit? I
> have the style of pump with the separate motor driving a pumping unit
> via a belt. I found a bunch of RV water pumps online, but none that
> match mine.
>
> I'd search for a part number but there isn't one on my pump! Not even
> a manufacturer label!
>
> Also, anyone know what sort of gpm and water pressure these pumps put
> out? I might like to upgrade to something a little more powerful if
> possible.



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