I'm trying to figure out which zone valve and flow regulating valve to use on an open loop system.  It seems that the Taco Geothermal Zone Valves are the preferred choice for this application.  However, my local plumbing supply shops only stock Honeywell zone valves (model V8043), which they tell me will work just fine for this application. Similarly, the Hays Measurflo seems to be the best choice (quieter and self cleaning) for a flow regulating valve, but the local shops only carry Dole flow regulating valves.

I can order the Taco and Hays products online easily enough, and the cost really isn't all that different either way. But somehow, I'm guessing that if I need to replace a broken part in mid-Winter, it'll be much handier to have something where I know the replacement part will be in stock locally.

Anyone have thoughts about this?

Flow controls may plug but not likely to break. Either is fine.
Don't know the model # on the Honeywell valve off the top of my head but I'll guess it's a hot water zonevalve not rated for the pressure of your well. Would it work in a pinch.....yep. Would i have you order the Taco's.....Yeah. I also recommend a flow rate gauge, it's worth teeing in to help with diagnostics.
Good luck,
joe

Thanks Joe - good advice.

You are right on the money about the Honeywell - it is a hot water zone valve rated for 125 psi max static pressure, but only 20 psi max close-off pressure The well pump pressure switch is set to 50psi on, 30 psi off, so close-off pressure across the valve could easily exceed 20 psi. In comparison, the taco geothermal are rated for 125 psi max static and 65 psi close-off.

The one local plumbing supply shop that has plenty of the Honeywell valves on the shelf says that these have been used everywhere in town for radiators, boilers, in-floor radiant, and heat-pumps, and that there's no need to go with anything more exotic. I'm still thinking I'm going to get the Tacos.

My installer has put p/t ports on the brass fittings going into and out of the heat pump - presumably these can be used for measuring pressure, temp, and flow.

Yeah p/t ports are for measuring flow and temp. I still suggest the gauge. Sometimes flow is measured by ga at less than a psi difference. That gets awfully subtle for a mechanical ga. Site glass lets you cross check.
Taco valves are the right ones for the job.
IMHO
j

How are P/T ports used to directly measure flow, or, are you referring to indirectly being able to measure flow?

I'm familiar with the technique of taking pressure measurements via the P/T ports, computing the pressure differential across the heat exchanger, and by using manufacturer supplied charts, looking up the equivalent flow.

But, are you saying, that beyond temperature and pressure measurements via a P/T port, that there are instruments you can insert to a P/T port and directly measure flow?

Best regards,

Bill

If you are asking me, no I know of know instrument that "directly" measures flow. I always install the float gauges as I'd been burned by a piece of floating debriss before. differences are subtle with the press diff calc you mentioned and wells vary in pressure (up and down so it is easy to be deceived).
j

Joe, thanks!

Best regards,

Bill

As a new GSHP owner, a flow meter is appreciated. By turning 2 ball valves, I can check the flow rate. As well, my 2 $10 thermometers, give me an indication, (not super accurate I know), of the temp of the water going in and exiting my hp.

I'm installing mine soon, but here is what I'm going with.

For the valves I was looking at Taco but got a recommendation for irrigation valves for an open loop system where the valve doesn't see hot water. Taco valves work through heating a wax element that expands, they are slow closing and opening, so an end switch turns on the compressor once fully open. These will certainly work well and reliably.

I have Hunter HPV irrigation valves ready for my system. These are popular well supported commercial use globe style irrigation valves with plenty of pressure rating. The are many companies that make something similar. They are instant opening, but are slow closing purposely designed to prevent water hammer. They also have a built in flow controller (an option to get with the valve when buying). They are also made to handle sediment in the water (although it should be filtered anyway if thats a problem), they are super easy to service, and best of all they are inexpensive (saved many hundreds over Taco cost and so cheap I got a couple extra to have as emergency spares).

I am then installing a true water meter (total gallons and GPM) near the outlet pipe but before bleed pipe to measure flow rate. I will have two geothermal units both 2-stage, so with one valve controlling the water flow on each stage I have 4 valves. I can use the valves flow controller to quickly and easily dial in the flow through each valve using the flow meter. I will also install fixed pressure gauges on each side of the geothermal units for comparison, but I decided not to rely on these and the chart to determine flow and install the true water meter.

I also obtained new industrial bi-metal water temperature gauges which will be installed on tees in the system piping to have constant readouts of temperature coming in from well, out from each unit, and mixed flow back out to well. All the data needed to setup the system and watch/control/maintain its operation will be instantly visible at all times without connecting to P/T plugs.

This is just how I'm going to do it, not how it needs to be done. I'd love to say its completed and have results to report but I don't yet.

 I piped my own Tranquilty 27, 3 ton, 2 stage, open loop system 2 years ago.  I ended up using a flow meter ("thermoflo" spring style) and for start/stop water flow I used 2 newer style TACO valve that is capacitor driven w/ end switch built in.  It takes much less VA than TACO valves recommended in the Climatemaster Installation Guide and has high shut off pressure rating (which I needed as my variable speed well controller is set at 68 psi and fluctuates above that at times), these valves were also quite a bit cheaper for me.  With these valves I still have plenty of power left for any other devices I might like to power off the units transformer in the future.  For flow regulation I just used (2) ball valves mounted directly upstream of the motorized shutoffs.  I used ball valves as I had heard some have had problems with the fixed oriface style regulators AND more importantly I wanted to be able to increase and decrease flow to see how it affected unit performance and more importantly (for me) pump energy.   This setup has worked well so far, although it can frustrate my wife when I have to explain from work how to adjust the stage ball valves and isolation ball valves in combination to ensure enough flow when running in 1st or 2nd stage, but also prevent water noise.    If one wanted to be cheap they wouldn't need the flow meter just a few tests with a known size bucket... run the discharge in and time what it takes to fill it.  Calculate your flowrate and adjust accordingly.  I prefer the flow meter as I can quickly see what the flow is at any time without test equipment. 

I hope to make some changes soon to accomodate a future water-to-water unit someday (maybe when I can get a tax credit for it !)... and then I plan to try brass stop and waste valves (in place of the ball valves) that should allow more gradual flow control adjustment.  With the ball valves you pretty much have no effect on flow until it is 80% closed :)  

I also installed dial temperature gages before and after the unit to be able to get a quick idea of how the unit is running.    

I Love the picture of the piping in the post above it looks GREAT compared to mine.  The following quote is very applicable to my piping.  An EXTREMELY heavyset plumber was trying to lighten the mood on a particularly difficult job site and told me ...  " I may not be fast, but when I get done it sure looks like !!"