Mikey
Aspiring Old Fart, EE, computer & networking geek
I've installed a Watts circulating pump under a bathroom sink at the far end of the plumbing lines to replace an older "Chili Pepper" appliance whose pump motor crapped out. I still use the control circuitry from the Chili Pepper, allowing on-demand operation of the Watts. Everything works great, and the dead-quiet Watts is a welcome change from the very loud Chili Pepper.
However... the Watts pump is a centrifugal pump, whereas the Chili Pepper pump was a geared pump. The geared (aka "positive displacement") pump also served as a valve, isolating the hot line from the cold line when the pump was off. The Watts pump, however, allows water to transfer between the two sides when the pump is off, leading to a couple of problems:
1) Water circulates constantly, due to convection in the loop; and
2) When you use water in the shower you always get an indeterminate mixture, regardless of the mixing valve setting.
The easiest way to solve this seems to be to place a valve in-line with the pump, which would open when the pump was on. A simple check valve comes to mind, but I'm not sure the Watts will generate enough pressure to open a check valve strong enough to resist unwanted flow. Since I'm operating on a limited budget, I first thought of a simple irrigation valve, or a washing-machine valve, which can be had for about $10, with a few bucks more for a 24VAC transformer for the irrigation valve. But it turns out that most of these are solenoid-operated diaphragm valves, which only work in one direction, whereas I have to stop flow both ways.
So... any suggestions? I've found some from industrial suppliers for big bucks, but I'd rather use something more commonplace (and cheaper) that some of the experts on this forum might have come across. Thanks for any help.
I see that somebody else was trying to solve a similar problem in March, but got no responses.
However... the Watts pump is a centrifugal pump, whereas the Chili Pepper pump was a geared pump. The geared (aka "positive displacement") pump also served as a valve, isolating the hot line from the cold line when the pump was off. The Watts pump, however, allows water to transfer between the two sides when the pump is off, leading to a couple of problems:
1) Water circulates constantly, due to convection in the loop; and
2) When you use water in the shower you always get an indeterminate mixture, regardless of the mixing valve setting.
The easiest way to solve this seems to be to place a valve in-line with the pump, which would open when the pump was on. A simple check valve comes to mind, but I'm not sure the Watts will generate enough pressure to open a check valve strong enough to resist unwanted flow. Since I'm operating on a limited budget, I first thought of a simple irrigation valve, or a washing-machine valve, which can be had for about $10, with a few bucks more for a 24VAC transformer for the irrigation valve. But it turns out that most of these are solenoid-operated diaphragm valves, which only work in one direction, whereas I have to stop flow both ways.
So... any suggestions? I've found some from industrial suppliers for big bucks, but I'd rather use something more commonplace (and cheaper) that some of the experts on this forum might have come across. Thanks for any help.
I see that somebody else was trying to solve a similar problem in March, but got no responses.
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