Installing a boiler feed valve question


Old 01-09-14, 03:06 PM
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Installing a boiler feed valve question

Thinking of adding a boiler feed valve on my system. My piping has a shutoff valve followed by a backflow preventer and then another shutoff valve.

I know I need to install it after the backflow preventer but should I install it before or after the last shutoff valve.
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Old 01-09-14, 03:39 PM
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I know I need to install it after the backflow preventer but should I install it before or after the last shutoff valve.
BEFORE. That will allow you to service the valve easily.

Before installing any new valves on the water feed line, FLUSH THE LINE UNDER FULL FLOW by rigging up a hose connection to the line and turning it on FULL BLAST to loosen the 'crud' that builds up in little used piping from domestic to boiler.

I like to add a 'flush valve' ahead of the valves for this purpose:

Drain/flush valve on the right. I hook hose to it periodically and flush a few gallons out. I'm on a private well and not chlorinated, so I have more than one reason to flush that 10' line between the boiler and the main line... don't want no creepy crawlies breeding in a plumbing 'dead end'.

The next item to the left of the drain is a 'WYE strainer' which now has a small valve on it for periodic flushing of the screen inside of it.

So, in order from the domestic to the boiler:

domestic->ball valve->drain/flush->wye strainer->backflow prev->reducing valve->ball valve->boiler

You don't really see the last ball valve in the picture because it's incorporated in the Watts RBFF expansion tank fitting (which is a real neat deal which AFAIK I invented and Watts owes me royalty checks for!) Since you don't have the RBFF, substitute a ball valve.

One other use for that drain ahead of the feed chain ... notice that the RBFF also has a drain on it, just behind the gauge. If my feed valve ever gets plugged or I want a FAST flush, I can connect a wash machine hose between the two and bypass the feed chain.

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