One of the things I've noticed over my time in the Boiler Room is that mixed in with all the various questions and discussion that apply to the particular issue are occasional "nuggets" of really useful information, such as products that do a really exceptional job, or have other features that make them different from just the generic versions that other companies make, tips and techniques that we can all benefit from, and so forth... These are great, but with all the volume of traffic we have, they tend to get buried in all the other messages and either not seen, or just hard to find later - "I know I saw something about .... that was really good, now where was it?"
I am starting this thread in an effort to save these useful tidbits for future reference, hopefully you will find it useful. In order to keep it visible and high quality, I'm making it a sticky, and closing it to all but Mods - What I'm hoping to do is paste in bits of interesting threads, with a link back to the original if anyone wants the context. Hopefully the Mod Squad will catch stuff that belongs here and add it as we go along, you can help by pointing stuff out that you'd like to propose for addition either by PM'ing us, or suggesting it in the threads themselves...
I also want this to be for those "extra-special" items - not stuff where there are lots of vendors, and the choice is largely one of opinion - so I WON'T be putting boilers in for example. OTOH, we have several pros that know about products that the rest of us might not find out about unless we spent way to much of our time buried in the product catalogs and such...
So to start off....
In this thread the subject came up about low head resistance flow check valves, and NoFossil was mentioning a desire for gasketted union style fittings -"in hot water" had some answers. See posts 42 & 43 especially.
In this thread, around post #20 I was grumbling about the way zone valves want power to hold them in their actuated (open or closed depending on the valve) position -
I am starting this thread in an effort to save these useful tidbits for future reference, hopefully you will find it useful. In order to keep it visible and high quality, I'm making it a sticky, and closing it to all but Mods - What I'm hoping to do is paste in bits of interesting threads, with a link back to the original if anyone wants the context. Hopefully the Mod Squad will catch stuff that belongs here and add it as we go along, you can help by pointing stuff out that you'd like to propose for addition either by PM'ing us, or suggesting it in the threads themselves...
I also want this to be for those "extra-special" items - not stuff where there are lots of vendors, and the choice is largely one of opinion - so I WON'T be putting boilers in for example. OTOH, we have several pros that know about products that the rest of us might not find out about unless we spent way to much of our time buried in the product catalogs and such...
So to start off....
In this thread the subject came up about low head resistance flow check valves, and NoFossil was mentioning a desire for gasketted union style fittings -"in hot water" had some answers. See posts 42 & 43 especially.
Watts and Combraco still offer inline, low pressure drop spring check valves.
Anytime you run piping vertically from a boiler or piping loop you really need a check on both supply and return side. Hot water can actually go up a return pipe and overheat a zone.
Same with an indirect water heater, without check protection on both supply and return they tend to over-heat just from hot to cold convection movement. Some old timers still use a pump AND a zone valve when piping indirects to assure a 100% shut off of flow.i
B&G;offers iso flange valves with that same check built in. It does move the check an inch or so away from the discharge.
Really discharge side is not a bad place for a check, you never want ANY flow restricting device on the inlet side of a circ, too much potential for flow restriction to start cavitation.
hr
Image Attachments (a couple of spec sheets)
Flanged gasketed fittings are very common in Europe and we are seeing more of it over here, especially in the solar industry.
The company I work for, Caleffi, manufacturers thousands of brass flanged fittings. If you need something special let me know.
But the real key to the excellent seal on those flanged fittings is that green gasket. Once some fluid hits them they swell and glue to the surfaces. When you disassemble one you end up scrapping the gasket from the fitting faces. Often times hand tight is enough with those gaskets.
<snip>
hr
In this thread, around post #20 I was grumbling about the way zone valves want power to hold them in their actuated (open or closed depending on the valve) position -
Gooserider - 27 August 2009 03:04 PM
What I’m kind of surprised is that nobody seems to have a zone valve design that only draws power when changing state… i.e. motor to open, then turns off with the valve staying open until it gets a signal to close, at which points it motors to close, and turns off until it gets a signal to open, etc. It doesn’t seem to me that it would be any harder / more expensive to build than the current style which seems to require constant power to maintain it’s active state, and does a spring loaded reversal if it looses power…
Gooserider
NoFossil responded:
The (broken link removed to http://www.taco-hvac.com/en/products/Electronic+Ball+Valve+EBV+Zone+Valve/products.html?current_category=69) does exactly what you suggest. The problem with zone valves is that the signal to close is the removal of power. With no power, how do you close the valve? Hence the spring. The Taco EBV stores enough power to close the valve after power is removed. It consumes essentially NO power, open or closed. I love them.