My Story - Saving another steam system

mikeg2015

gfrbrookline said:

All of my main vents are on antlers off of a 3/4 fitting, worked wonders.
I would suggest either ventrite #1 or Hoffman 1A vents for the rads. They can easily be adjusted so you can fine tune all of the rads. I tried the Gorton and Mom but wasn't thrilled.

I have 1x Gorton 2, a big mouth and 2 Gorton 1's to maximize the 3/4" tapping. Plus 2 more varivents on the main, and 1 varivent about 5' down above the first elbow on longest runout to the master bedroom.

I have 1A's on 3 radiators, 1 ventrite, and mix of Gortons and Maid-o-Mist, 2 Hoffman 40's and 2 varivents at the very end.

The challenge is a 1A only have a range between approx. a #5 - #6. Ventrite, between a #4 - #5. A Hoffman 40 it right between a 4 & 5 and I have a bunch of those I pulled off.

In my "inventory", I also have:

1) A TON of Gorton C's and D's.
2) couple 70A Airports which are obsolete, but just slightly larger than a 40.
3) A old Riselt #2? I think it says. It's a 2 piece assembly, solid brass. No idea what it's venting rate is. It still works. It was mounted to a radiator that was laying by a shed out back. Probably was used as a replacement at some point in the 40's I'd guess. Probably a non vacuum vent and replaced a failing #2.
4) 1 working Hoffman #2 vacuum vent that ironically was on the largest radiator. BUT, wondering if a vacuum vent almost works better on a larger radiator like that. I might install it on a very small entry way radiator in my entry way.

Just have to keep fiddling with it to get it all balanced.

mikeg2015

Quick Update:

Replace 1/2 the vents with Ventrites and Gorton/MoM 4's plus a really old cute little vent I found on a radiator that was laying out back behind the shed. I think it's from the 30's. Heavy, solid brass, 2 piece threaded together I assume has an alcohol filled float like a Hoffman 40. Slowed everything down and it's working well.

Added more main venting by tapping a couple more 1/4" holes and using some extra Varivents I had. I removed all the insulation on the dry return header after the last run out. Wanted a little more heat in the basement there anyway. Warms the kitchen, foyer and dining room floors a little, which is nice. Discovered a galvanized elbow and the 2-1/2" union is galvanized. So i can see where the boiler replacement started.

I have things pretty well balanced, heating up at the same time. Minimal noise on vents.

Still have some whistling on shutdown after a longer run as steam collapses to vacuum. Adding more main venting helped a little but didn't fix it. Almost tempted to add a small vacuum breaker on it to to quiet it. Fortunately it doesn't do it on the upstairs radiators. Of course, the system originall have Hoffman #2's (still have 1 I took off one radiator) and probably a 76 or 11 on the main. With a slightly smaller boiler, it would work really well I think.

Still having issues with the autofill on both LWCO, it overfilled the boiler yesterday, but the vaporstat prevents it from firing when flooded.

Operating numbers:

Main venting phase: <0.5-0.9oz (5 minutes from a warm (but not hot) start. Haven't timed a hot start but i suspect it's under 2 minutes.

Heating phase: 1-1.5oz. Vaprostat set at 4oz. pressure doensn't build until all radiators are filled.

Boiler size: 375k input (300k nameplate output)
EDR: 710

I think a 275k would be about right a 250 might work well too if I slow the venting down even more.


Question, will the big mouth vent, if still hot, open under vacuum?

EBEBRATT-Ed

why not just install a 1/2 or 3/4 inch check valve as a vacuum breaker if the noise is a problem

mikeg2015

I think i might. Good idea. Could just add it to the end of the main vent tree. Will obviously need to make sure its rated for at least 240F max.