Low GPM water pump?

 My recirculating water pump is leaking again...

I've been using a closed loop water heating system in the basement of
my home.
I didn't design it but when I bought the house it was there, so why not
use it?

The water pump is driven by a 1/8hp AC electrical motor which doesn't
seem to be too efficient but the real problem are the seals on the
water pump end.  It uses some sort of ceramic seal.  Last year, I
replaced this seal because the old one had cracked.  This year, the
brand new part is leaking again.  This time, the seal is not cracked
but it has deep grooves in it and it is leaking.

What I am looking for, is a totally different system that cannot
possibly ever leak in a million years.
I've actually thought of designing my own system but if one is already
available then why re-invent the wheel, so to speak?  The idea is to
have a magnetic impeller inside of a non conducting tube.  Then, I
would install an AC coil over this tube.  Once AC power is applied to
the coil, the magnetic impeller inside of the tube should spin and move
the water.  I only need about a gallon per minute, to circulate the hot
water around the closed loop.  Anything more, would not prove to be of
any benefit.

If anyone has any constructive ideas or thoughts on how to achieve
this, I'm listening?

  wrote:

<http://shop.solardirect.com/product_info.php?El_Sid_Pump_Motor_Driver_Made_by_Ivan_Labs%2C_Inc_&products_idB2>

Available many places, fits over the same sealed mag-drive pump module
used by March and other companies. I've run several for years. Quieter
than motor-driven pumps, and very power efficient.

I've seen one that occasionally (maybe once a month) failed to start
when powered on, which can be bad if you run a solar or wood fired
system with no instant emergency shutoff! Another one has failed to
start only once in over five years. If you _absolutely_ need to have
flow whenever the controller calls for it, provide a conventional pump
for backup. I actually have a redundant controller for my backup pump
- ever see a large solar hot water array overheat?

Loren

 

Thanks for the link, Loren.  This is exactly what I was looking for.
Thanks again...

-------------------------------
Loren Amelang wrote:

<http://shop.solardirect.com/product_info.php?El_Sid_Pump_Motor_Driver_Made_by_Ivan_Labs%2C_Inc_&products_idB2>

 


It seems like there are quite a few of these magnetic water pumps in
use and they can handle reasonably hot water.  They are being used in
washing machines and dish washers for draining the water when the cycle
has finished.  I might try experimenting with one of these units just
for fun.  I'll start by trying to adapt a better motor to the system
for continuous operation.  Thanks for the help everyone, it is much
appreciated.

 

Buy_Sell wrote:

Magnetically coupled pumps are extremely common in the chemical handling
world. All the film auto processors have several small ones to circulate
the developer, fix and rinse baths. Last time I looked
http://www.surpluscenter.com  had some mag pumps in stock.

Pete C.