Piping practice?

[kuribo]

Is it standard practice to put shut off/isolation valves on each side of every component in a hydronic system? Seems safe but with two storage tanks and 4 zones, 10 manifolds, that is a lot of valves...

Thanks.

 

[peakbagger]

You should never put an isolation valve between a boiler and a safety relief valve but other than that how much is your time worth and how critical is it that you can isolate a system quickly and repair it? Most folks put valves on components that wear and will require replacement, that would be pumps, automated valves, expansion tanks and air vents. I try to isolate major piping runs. Having dealt with large industrial systems without adequate drains and valves, I planned on a small leak can take several orders of magnitude of time for a system that will not drain than one that does. If you cut down on Isolation valves, make darn sure that you install low point drains as odds are you will need to drain larger volumes of water due to lack of isolation.

I have a conventional oil burner in my system, I have manual valves set up so that if they are closed and the power turned off to the wood boiler controls, that the oil boiler runs as though the wood boiler was never there. That way if I am not there and the heating system acts up, there is no finger pointing by the service tech about the wood boiler screwing up the oil boiler.

 

[maple1]

I have too many valves to easily count. Every component is (or can be) isolated. Has paid dividends several times over the years.

10 manifolds?

 

[mikefrommaine]

The more unions and valves the better. Ordering online is usually cheaper. Unless your running 100k a year through a supply house.

I like pexsupply but there are others.

 

[ewdudley]

Depending on your layout if you put some thought into it you can eliminate a lot of valves. You need to be able to replace components without draining much, and you have to be able to force air out of each of your circuits one at a time.

Mine I ended up with one valve on the supply side where supply feeds the mixing valve, one valve on the return side, one valve on the return end of each circuit, and one valve on the supply end of each circuit on the downstream side of each zone valve, plus one valve on each end open to the outside for feeding and expelling purge water.

To replace mixing valve, circ pump, or a zone valve I turn off each end of each circuit and the supply and return valve and don't lose more than a cup and a half opening up. To purge just hook up purge supply and purge individual circuits as needed.

 

[kuribo]

Thanks for all the replies...very helpful!

 

[tmudd]

E.W You are right. A good system isolates areas that can be drained and easily purged. I think laying out beforehand with thought toward tweaking the system and sevicablilty are of prime importance in mechanical work. The isolation can help you also determine where the problems originate and locate efficient areas. I put in several zones conisting of radiant pex underfloor along with a heat exchanger in existing central ductwork . I used Bob Rhor's excellent primary seconary piping idea. It gives me isolation possibilities with a high temp portion and low temp by way of a mixing valve. It sure makes you appreciate the values of low temp radiant. It gives me floor heat down to about 100 degrees which keep the mass of the building heated. All you posters with experience have brought this forum to be one of the best resources in my world.

Here's to the best system.
TLM