SPEWING STEAM VALVE

klal

I've got a single pipe steam system with copper convectors in a two story (not counting the basement, where the boiler is located) frame house, properly installed header, Hartford loop, pressure control set between 1.5 and 2 I believe. When I purchased the home, I relocated a single radiator with a run of pipe I piped myself (it is pitched properly, but I did split a single riser—I know not kosher, but the other on the line it splits from heats fine). That relocated run has always had issues getting heat unless the system was on for a good amount of time (if I overrided to a much higher temperature for instance), and when it finally did get heat, it would water hammer and gurgle/spew brown water. The current valves on the relocated radiator and the other radiator on the same run are variable slide vents from the local box store so I know they're junk. I recently replaced an old 84 year old Ideal Red Flash #1 Boiler with a new Weil McLain EG-50 unit and now the relocated radiator gets heat with the other radiators, but it still spews, but now only clean water. From what I've been reading on your wall, one of the recommended fixes could be a valve replacement. I currently have two Gorton #1 on my mains, and it the house is a combination of Gorton #5 and I think Hoffman (bullet style), regardless of the floor. What would be a good Gorton to try on this suspect radiator and its shared line mate, and does it make sense to replace the Gorton #5's on the first level (one story above the boiler) with Gorton #4's leaving only Gorton #5's on the second level (two stories above the boiler)?

Steamhead

Sounds like a pitch problem where the water is collecting in the pipe. The pipes connecting the convectors to the mains must slope back toward the mains at a minimum of 1 inch in 10 feet, and more if possible.

Another possibility is the pipe was not big enough to support the added radiation.

Post some pics and let's have a look.

Fred

Does that problem vent close when steam hits it? Does steam ever get that far down the rad to close that vent? From what you describe, it sounds like that radiator may not be pitched back towards the supply pipe, but it could also be that those two radiators are creating more condensate than the steam supply pipe can handle, when pushing steam into those rads. What size is the supply pipe to those rads? What is the total (combined) EDR of those two rads? Post a picture of the set up.
It could also be cheap Big Box store vents.

klal

The radiator is definitely pitching back to the supply lines, perhaps overly so, and the companion is too—a quarter bubble off the level, but I can raise that some more if you think it may help. As for the slope to the main, I can't verify completely, as the area they run through is closed up now, but I seem to remember pitching at 1/4 per foot, and they are 1 inch black pipe coming off the mains and up to the radiators. As for the EDR, I'm not absolutely certain how to calculate, but the radiator enclosure that is spewing is 31.5 wide by 20 tall by 5.5 deep, the companion on that run is 17 wide by 20 tall by 5.5 deep, they both are steel enclosures and the copper and cast iron ended convectors themselves are about 6 inches tall and 5.5 deep. As for the valve, I don't know if the vent is closing or not, as I mentioned, the radiator gets hot, spews, and radiates afterwards, but I'm not sure the valve is open or closed during that process. Right now I only have access to the main and the "split" I put in place, the run of pipe feeding the problem radiator disappears into the subfloor of the room it is feeding for approximately 8 feet. I don't mind opening up the space the pipes are running through to check the pitch, but I'd likely do that in warm weather.

Jamie Hall

That vent should close when steam hits it. If it doesn't, it will let steam and water out, as you describe. First thing I'd do is check -- or change -- that vent.

Fred

You don't need to pitch them anymore than what you already have. Copper Convectors are either 4.25" or 6.25" or 8.25 deep. Recheck your measurement. In any case, if those two convectors are 4.25" deep, EDR totals about 24.5 sq. ft. If they are 6.25", the total EDR is about 35 sq. ft. A 1" supply pipe should work with 24 sq. ft., might be on the edge for 35 sq. ft. especially with condensate flowing back from two directions. That may have an impact on steam capacity. As has been said, change out that vent with a quality vent, Vent-rite adjustable, Maid-o-mist adjustable (with changeable orifices) or Hoffman 1A adjustable vent and see if that solves the problem.

nicholas bonham-carter

Max out the main vents, and put slow Hoffman vents on the rads. This will keep the steam velocity down in the takeoffs to the radiators, and that may help, if the pressure is in the ounces range,--NBC