Zone Valve Question

[Clarkbug]

So in searching, it seems like lots of people here like the Taco EBV as a zone valve.

Well it turns out they are discontinuing these, and instead they are going to get replaced with the "Zone Sentry" valve.

http://taco-hvac.com/en/products/Zone Sentry^® Zone Valve/products.html?current_category=396

I dont know much about them (my existing system is zoned with circs), but is there any major difference between the zone sentry and the EBV? It looks like they are very similar to me.

Im thinking about using one for my setup when the oil backup is firing, but I see they only come in sizes up to 1". I would guess thats OK, since the rest of the piping would be 1 1/4", so its a small restriction. The only thing that makes me a little nervous is that the literature states that its the equivalent of 47.4 feet of pipe, but Im pretty sure Im thinking about that the wrong way.

But any thoughts on these valves?

 

[ewdudley]

The only thing that makes me a little nervous is that the literature states that its the equivalent of 47.4 feet of pipe, but Im pretty sure Im thinking about that the wrong way.

But any thoughts on these valves?

They're very appealing valves until you look at the Cv's. If I remember right it seemed like the 1/2", 3/4", and 1" all had the same 1/2" guts, so the larger valves only have a larger form-factor.

Your system appears to be based on the Tarm PT1C concept diagram. There's a PT1ZV concept drawing that differs from the PT1C only in that it uses a weighted check instead of ZV-1. The check valve version might do what you need. (The drawing with the zone valve is PT1C and the one with the check valve is PT1ZV, go figure.)

--ewd

 

[Clarkbug]

Once again I thank you Eliot.

I am intending to use the PT1 diagram almost exactly, with just a few tweaks to fit the Varmebaronen tappings and my existing system. I had looked at the PT1C and PT1ZV, and I thought the difference was that they showed one system zoned with zone valves, and the other zoned with circulators. I didnt even notice that one was missing a zone valve entirely.

Ill wait until my brain recharges a little in the morning to trace out the flow. I guess I would wonder why would anyone use the zone valve instead of the check?

 

[mikefrommaine]

I need a normally open zone valve for a no power dump zone. Looks like the sentry valves are sold as a normally closed actuator and valve body package only?

I would then need to buy a different normally open actuator.

http://www.pexsupply.com/pex/control/search?SEARCH_STRING=Sentry+valve

Would the ebv valve be too much of a flow restriction?

 

[ewdudley]

I had looked at the PT1C and PT1ZV, and I thought the difference was that they showed one system zoned with zone valves, and the other zoned with circulators. I didnt even notice that one was missing a zone valve entirely.

Ill wait until my brain recharges a little in the morning to trace out the flow. I guess I would wonder why would anyone use the zone valve instead of the check?

Good catch, I missed the zoning with circs vs. zoning with zone valves. It looks like when zoning with circs you need ZV-1 to prevent multiple zone circs from overwhelming the weighted check valve in the PT1ZV drawing.

But the 1" Zone Sentry has a Cv of 8.9, which could well be plenty for you situation. When I made discouraging comments about the Cv earlier I may have been thinking about the 5000 series mixing valves that have some pretty miserable Cvs.

On a side note, I believe Tarm normally specs a 172 degF minimum return diverter, which seems pretty hot even for baseboard system. You may want something lower.

 

[nate379]

Those make cheap zone valves. I used the std gold power head Taco valves, they were ~$150 each. I have 5 of them on my system. 3 zones in the house and 2 seperate zones in the garage.

 

[peakbagger]

For what its worth, I just purchased two 1" Taco EBV zone valves. I took a new valve out of the box and attempted to manually open it using the manual actuator. The valve didnt open and the shaft connecting the manual actuator disk to the valve broke. I then tried the same thing with the other valve, it would not open and I expect that if I kept cranking it also would have broke. I then removed the good actuator and manually turned the actual valve shaft, after some initial resistance, it turned freely. I then slipped on the actuator and the manual actuator worked. I have alerted customer service at Taco and have asked how to go about getting a replacement actuator.

Looking at the shaft to the manual actuator, it is a very small diameter nylon(?) shaft which I suspect is undersized. I havent yet tested to see if the valve works when voltage is applied to it. Obviously, the ball valve was slightly bound up when shipped and that caused a higher then designed torque on the shaft during the initial operation. I wonder what happens after the valve has sat in one position for long period of time in an operating system?

These are sweat in valves and there is an installation tag attached to the actuator head indicating that the valve needs to be operated manually a couple of times after soldering. I expect someone would be very unhappy if they followed the directions and broke the actuators.

I bought the valves because of the new technology and the low operating load, it looks like I may be stuck with some marginally designed valve actuators. I normally use Honeywell automated valves and this was a first try for Taco valves, its too bad as in the past Taco was reasonably robust.

I will let folks know about my experiences with Taco and the outcome.

 

[Clarkbug]

Thanks peakbagger and Nate.

I wonder if the problems with the EBV is why they are getting phased out and replaced with the Sentry. I wish I could find the link I had that mentioned that...

Hmmm, I was thinking this would be ideal for me since they are low power and relatively fast acting, and thats what I really need it for (My house is zoned with circulators, not zone valves).

Maybe I need to look at some of the B&G valves or something.

Which as a side note, I saw the new Bell & Gossett Ecocircs today, and was impressed.

http://completewatersystems.com/?product=ecocirc®-auto-and-vario

No direct connection between motor and the cartridge, its a magnetic coupling, all stainless steel, one lock ring and a seal and you can replace everything. They have an automatic version and one that you can manually set the speed. Running wattage at full load is 63w I think, but its only rated to 203 deg F. Looks very cool, but I dont think it will help me in my system.

 

[peakbagger]

After looking at the catalog, the failed valve referred to in my prior post was a zone sentry valve. Taco has responded to my request to replace the actuator. They did not admit to a problem and indicated that I attempted to turn the valve manually without pressing in the actuator button which leads to a failure. Considering that I had another valve for reference with the same issue of a initially frozen ball, I dont agree, but they will send me a new actuator once they recieve the old one. I will be very tender with the manual actuator in the future and probably remove the actuator head and turn it manually rather than taking a chance of breaking it.

 

[Clarkbug]

Thanks for the insight peakbagger.

I still need to go pick up a zone valve, so Im trying to decide if this is going to be the right choice or not for me. I dont plan on ever having to manually actuate it, but I know how plans go...

 

[Fred61]

I picked up a White Rodgers one inch high flow zone valve recently. I assumed they came only in normally closed (NC) which is what I needed. In reading the installation instructions I see they also refer to a normally open (NO) valve. I like the way the valve operates. Perhaps you could search to for an (NO) in this configuration.

 

[Clarkbug]

I picked up a White Rodgers one inch high flow zone valve recently. I assumed they came only in normally closed (NC) which is what I needed. In reading the installation instructions I see they also refer to a normally open (NO) valve. I like the way the valve operates. Perhaps you could search to for an (NO) in this configuration.

I like where you are going with that Fred, but I think MikefromMaine needs something with a little quicker actuation. It looks like the cycle time on the W-R valve is 45 seconds, which I would think is a long time to wait for your dump zone to activate.

Maybe Im just thinking about it wrong, but I would think you want something that works quicker than that. Thoughts?