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Master Valve for system
What's the opinion for a master valve prior to the 1st manifold?
Good Idea? Not? I have the room to install one but don't know if it's necessary.
If so, what type is best, what size Master Valve for a 1" main line?
Thanks
paterjb
What is your reasoning for wanting a Master Valve? (I assume you are talking about a Master Control Value as opposed to a manual cutoff valve).
The down sides that I can think of is that you will have yet another mechanical device that could go wrong and you will lose water pressure going through another valve.
The up side that I can think of is that you will have more flexability in the pipe that is after the feeder valve (because the uniform plumbing code, as I understand it, says that you need to have any Main Line Pipes (pipes that are under constant pressure) be either metal or buried at least 18" deep).
As for what size, I recently read somewhere that it was suggested that your valve size be one size smaller than your pipe (any others have input on that statement?). Otherwise, you have to consider not only the size of your pipe but also your water pressure, your gpm flow rate, and the performance specs for the vavles you are considering to get the "right" answer.
What is the reason for a master valve?
I only install master valves on self-draining systems.
Let us know your reason!
Reason is economics/safety. Maybe it's overkill.
I am installing 9, 1" Irritrol 2400T zone valves with auto-drains on each zone. Thought that if any of the zone valves leaked, the master valve would be a good Idea. Any thoughts?
If after hearing advice from the forum I go ahead with the master control valve, what type should I buy for least pressure loss and what size? Thanks
Paterjob, Master valve is not to prevent leaks. If your valves are leaking while activated you would need to fix that. Your master valve could leak just as well. If your looking for something to prevent water flow if a valve or a head blows, look into Flow Click by Hunter. I've been selling these as options into a systems. As soon as you tell a homeowner what their purpose is, they buy in.
And if you end up using a master valve remember to use and ASV instead of a PVB. PVB's are meant to stay under constant pressure.
Aquamatic or others: If one of my 9 zone valves has a small leak in the closed position and I have drain valves that need > 8 psi to close, won't I be leaking water out the drain valves and not know it? Just asking.
Also, RVLI or others. What is the difference in a ASV vs PVB. Won't my 9 zone valves be under constant pressure when in the off position?Thanks
Paterjb
. Do you mean drain valves at the end of your line?? If they are leaking- thats fine- Thats what they should be doing as long as you have fully closed valves. You might also have some sand or object stuck in the valve that causes a void in the seal. Open up and check each one. One way to check for any leaks if you have city water. Is to make sure that all water is shutoff through out house. Then go to your meter and check to see if your flow meter is spinning. Now this of course can also mean you have a small leak somewhere else in the house ( faucet). If you have a shut off after your T'ed off for the sprinklers, SHut this off, Now you should only have pressure on the sprinkler line.
Aquamatic: I haven't installed my system yet. Still fishing for the best advice. I'm saying that if my automatic drain valves have already drained, and I have a leak in one of my zone valves allowing water to leak by, then the master valve would be one more stop gap to ensure I'm not wasting water.
Do you have freezing winters in your area. If so are you trying to avoid compressed air in the winter? Around my area no one uses drain valves.
As for the master- You got a point, if you want to spend the extra money go for it. Be sure its a heavy duty master that will not leak as easily