replacing steam vents

borner

Hello, I was thinking about replacing my old adjustable vent rite vents with some Gorton fixed valves.

The main reasons are 1) I believe my main vent is too small (Ventrite 35)
2) I want to place some little valves on some of the vents to turn off radiators in un-occupied parts of the house
2A) The vents are 1/8" NPT... right? This is an acceptable way to turn the radiators off?
3) The vents are old.. should probably be replaced right?
4) gives me an excuse to order the Steamaster tablets (shipping isn't as bad.... this is a poor excuse)

I was Hoping I could ask your help to see if the vent sizing made sense,

I was thinking:
Dining room (thermostat location) #4
Living room #5
both bedrooms #6
Bathroom already has #D
Upstairs #6 or #C
The replace the main vent with #1 or #2?

Thanks again for your help!

Additional information, radiator dims:
Dining Room: 36"x9"x19" 3 column 15 section
Living Room: 42"x9"x19" 3 column 17 section
Bedroom 1: 16"x9"x34" 3 column 6 section
Bathroom: 12"x9"x24" 3 column 5 section
Bedroom2: 14"x9"x34" 3 column 6 section

dennis53

It sounds like you already have the ideal radiator vents with the adjustable Vent-Rites. I would recommend replacing the undersized main vent with at least one Gorton #2 if space allows, then fine tune each radiator.
Dennis

Abracadabra

Don't use D or C vents. Tends to throw your balancing out of whack. I will usually use a 4 or 5. Vent the mains fast and radiators slow to be able to balance out your system.

KC_Jones

You should also get your main venting corrected before you try and balance the radiators at all, no matter what you end up doing with them. The rule of thumb is 1 Gorton #2 for every 20' of 2" pipe. Also you only show 1 main vent in your diagram, but what appears to be 3 mains? All the mains in the basement should have a vent.

jbmoff

Quick question.... What if the mains are 2" and 24 feet? Still only 1 Gorton #2?

Local1Plumber

I agree with KC_Jones that all of your mains should have end of main air vents. I had a similar issue at my house where there is more than one supply main- in addition, one side of the house is parallel flow and the other counter. The parallel flow had a main vent, the counterflow didn't. Cutting in a Tee was not an option for me as all the piping was covered with asbestos insulation. I instead, at the furthest radiator on that run, removed the angle style radiator valve and installed a 1"x3/4"x1" tee with a straight style radiator valve piped into the bowl and a 6" x 3/4" nipple and coupling on the vertical run with an end of main Gorton #1 on the outlet of the coupling. I had to shimmy my radiator over a bit to make this happen but it definitely did the trick.

ChrisJ

Just to make things more confusing,
I'm using two Gorton C vents and I believe one Gorton 6 vent in my system and on fairly small radiators.

If I stuck to only 4's and 5's my system could never work at the low pressures it does, some runouts are just too long and there's too much pressure drop.

Personally, if I was going to balance my system for the first time I'd probably start with mostly 5's and 6's depending on the location and radiator size and then work from there. You will be ordering more vents for fine tuning without a doubt. If some rooms overheat, go to a size smaller, if some are too cool, go a size bigger etc.

ChrisJ

This shows the vents I'm using.

The number in the middle of each radiator is it's EDR rating. The single digit in the vent location is the number Gorton. The system is incredibly balanced all year from 50F to -8F ambient.

ChrisJ

Hatterasguy said:

ChrisJ said:

Just to make things more confusing,
I'm using two Gorton C vents and I believe one Gorton 6 vent in my system and on fairly small radiators.

When you need a Magnehelic to see any pressure, you're in a world all by yourself.........................

In more ways than one.....
But that's another story.

It's still true, I'm betting many systems can use 6s and Cs as long as the piping can handle it and the steam doesn't take a short cut across the bottom of the radiator and shut the vent (large tube / small tube radiators like mine). If you vent a large or small tube radiator and suddenly the steam cuts across the bottom barely heating the tubes you need to slow it down. I've had this happen a few times. My downstairs bathroom does it with a G6 as indicated on my drawing. The top of the stairs one also does it with a G6 even though it's almost the same size radiator as the two I have GCs on. It's because of the lower pressure drop to it so steam goes in with more force.

I feel radiators should be vented as fast as possible without throwing the balance out. This takes time, patience and buying a few extra vents.

gennady

I would not balance system with radiator vents. I would install master vents and make sure that steam comes to each end of the mains at the same time, and to the top of the risers at the same time without back pressure of the air.