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Inside Heat-timer Varivalve Radiator Vents
Ever wonder what's inside a Varivalve vent? Or what makes them spit water or why they fail?
I looked inside. I really wanted to love these. Beautifully machined American made brass gems that emit a bodacious amount of air - faster than many main vents. An adjustable slide varies the output. Good if you have a clean, dry steam system and bad if you have anything else.
Advantages are a self cleaning valve seat, an o-ring valve that seals against the seat and a bronze sylphon, just like a little steam trap. Disadvantages are no float to keep squiring water off your floors, and the fatal one to most of these vents - a plunger that falls out from the sylphon bellows sealing its seat permanently.
In the cut-away below, you'll see the brass "plunger" that the bellows presses against the seat when the valve closes. Unfortunately this plunger is retained in the bellows with a press-fit. After the bellows expand and contract over and over again, the bellows swell and distort, finally ejecting the plunger out of the bellows and onto the seat. Gravity then keeps it there - plugging the seat forever.
And that's the end of the valve. About a third of the ones we've installed have failed this way in the first two years.
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Below is the original 1950's "temperature adjustable" Heat-timer adjustable vent. "The radiator vent with a built-in thermostat" also spat water but was constructed differently and didn't fail closed like the present design. The "factory calibrated thermostat" knob on top simply raised or lowered the sylphon bellows lifting the plunger from the seat:
Re: Help with boiler
you're confusing 2 different tanks, heating, and domestic,
heating system wants to be set at 12 psi air, then take your heating system water pressure back up to the 12 psi fill, it shouldn't take much water unless you have air in the system also,
you asked how adding 6 water doesn't add to your 12 air, well 12 air is stronger than 6 water, so it stands its ground, when your cold fill 12 water heats up it expands, and THEN it will push on the 12 air, and sinse the air is compressable, the air psi increases(and water will some too),
set you air to 12, add water to 12, and let it fly,
that tank in your picture is a domestic hot tank, so it's air pressure needs to match or slightly exceed your well or street pressure coming into the house, then when the domestic water heats up and needs a place to expand to, that tank takes that expansion,
I think the pictured tank is on your heating system, and that's ok, set the air to 12, and add heating water pressure back up to 12, let it fly,
neilc
Re: Piping for New Steam Boiler
@delcrossv thank you for that explanation. And your 100% right, it never heated much and in fact the steam would not make it past the first rib. Now I know why! I will connect with the other dry return into the wet as we previously discussed. I will draw a plan based on our discussion to make sure I did not miss anything important…but I believe without your pointers and insight I would be guessing with some of the connections…so thank you very much!!!
Noah_1
Re: “That’s an easy job”
Haha. I learned the hard way not to say that when I walked out the door to fix a problem.
Just like I don't say "I'll be back in an hour"
Took half a lifetime to learn that.
“That’s an easy job”
I posted this on our town’s FB page and it seems to be resonating:
Neighbors, when hiring a trades person, don't say "it's an easy job"
After 36 years of small business, and thousands of interactions with home/property owners, may I offer an opinion: This will not help you. Just describe the job and stop talking😀
Small story then I will go away. My new-ish and expensive plow stopped working a couple of days ago. The local plow shop (where I bought the equipment) says, "Come down tomorrow after lunch, we will fit you in". I get there and there's a couple people sitting in the waiting room. I'm told "it's going to be a while, have a seat".
The place is busy, phones ringing and people walking in. I'm a fly on the wall, absorbing the mood of all the staff and walk-ins.
One guy walks in and says, "The lights aren't coming on, it's probably something simple, yet I'm not a wiring guy". I cringe----uh oh. He broke the golden rule.
The owner pipes up: "it's never easy, we will need to take a look, but I've got people ahead of you". The guy literally repeats himself. I cringe again. The owner politely tells him to fly.
He takes off. The office lady and I have a small chuckle. "If it's so easy, he should do it himself"
Plow got fixed, my life went back to normal. You don't need these trades people 'until you need them'!
GW
Re: “That’s an easy job”
As we age..our days are numbered..won't suffer fools, gladly..Mad Dog
Re: 2 problems on a 1 pipe system
That's cute. What on earth do you suppose it was meant to do?
Re: Radiant Floor Heat- Circulator Runs too much?
In an ideal floor radiant system, the circulator will run constantly. An outdoor reset will be used to vary the circulating water temperature as needed, with a room temperature sensor to trim the water temperature. How that is accomplished varies with the system — but in any case the floor circuits are running all the time.
Re: Long-term project to update old hydronic -- let's start with the Mercoid switch!
Nice! I found this post
in which Dan himself points us to this document from B&G:
This has some nice tables estimating water volume for radiators and other components.
I measured all the piping, added up all the radiators, assumed 48 gallons for the furnace (from that B&G document and in agreement with Matt), and come up with a system volume of 211 gallons. (As a bonus, I finally determined the EDR's of all my radiators!)
The B&G document then has tables for recommended tank size under different conditions, and for me it recommends a 25 gallon tank. With the same input, the Amtrol sizing tool comes up with a 20 gallon tank. I am currently rocking a 6.7 gallon tank. So, I suppose that after finishing out some of the remaining tests, like the ones Matt suggested, I will probably invest in a larger tank. As my wife pointed out, even after we replace the old furnace, we will still have a large charge of water that needs a big tank.
