Zone Valve question

[tazcrash69]

OK, After taking a look at this post: http://www.plantedtank.net/forums/di...-solenoid.html about a possible solenoid, I thought to myself, that looks a whole lot like the zone valve on my boiler.
http://pexsupply.com/Categories.asp?cID=281&brandid=

Now I know that was was kind of pricey, and it has copper, and slow to open, but can anyone tell me why something like this would not be a good option on the drain side of a built in water changer with a good check valve between it and the tank?
So it's slow to open, and close, is it a big deal on the drain side? I wouldn't think so.
Granted they are designed to be used on a closed loop system so any leaking in home heating is not an issue, but on a tank drain it could be.

anyone have any experience using these for a water changer?

[PDX-PLT]

See my post in this thread: http://www.plantedtank.net/forums/di...noids-how.html

BTW, that Honeywell valve's spec sheet says not to use it with oxygen-containing water for some reason.

I think these look good: http://pexsupply.com/categories.asp?cID=349&brandid=

[AndrewH]

How much water are you looking to drain at a time?

I'm using a 1/4" solenoid valve at $30 each. It does take a while to fill a tank, but it gets there eventually (my best guess is 20-30 minutes to fill 20%-25% of my 90 gallon).

[original kuhli]

The trick is when you're filling its at 60 to 80psi head loss across the solenoid, on drain you'll be lucky to see 10psi from what I can gather. Much larger orfices(or pressure) are required to achieve reasonable drain rates...

I'm trying to get a conventional diaphram type 3/4 drain solenoid to provide a reasonable rate and its been pretty disappointing thus far. 1/4 inch line/solenoid will be fine for the fill.

I'm going to try a booster pump and see how my rate goes then, the backup plan is a 3 way valve and a booster pump...

[LS6 Tommy]

The Honeywell & Taco zone valves can't be used as a drain. They'll leak like a sive. All zone valves are meant to do is control H2O flow in hydronic heating systems. They're not solenoid valves. They have a motor that opens a rubber "plug" that seats inside the valve body, which stops the flow of water through the pipes in that zone.

Tommy

[tazcrash69]

Thanks Tommy, this is really what I was wondering. I've had t9o replace a motor on one, but never installed to check out the insides.

OK, back to finding a RedHat.

[PDX-PLT]

Originally Posted by LS6 Tommy

The Honeywell & Taco zone valves can't be used as a drain. They'll leak like a sive. All zone valves are meant to do is control H2O flow in hydronic heating systems. They're not solenoid valves. They have a motor that opens a rubber "plug" that seats inside the valve body, which stops the flow of water through the pipes in that zone.

That's why, I think, those particular ones have such a low rated maximum cutoff pressure; typically 15 psi or so. Use them in normal tap pressure, and they leak. But for a drain they might not. They're cheap enough on eBay sometimes they're worth a try.

The Taco EBV's are actual ball valves, and have a cutoff pressure of 150 psi. Those ight work better with higher pressures.