STEAM

John Barba_6

Hi:

I read the Lost Art & "Balancing Steam Systems Using a Venting Capacity Chart" and went to work...

I measured, calculated the air volume of the mains/runouts/rads, and replaced the vents on the two mains (Gorton #1s on each) and the radiator vents (Gorton #s 6/C/D). I did all the calcs based on a desired 3 minute venting of the mains and then a 3 minute venting of the rads but am still having issues with a few radiators. Three of my column rads are not getting hot past the first few sections when all of the tube ones are screaming hot and I'm beating my head against the wall!!!!

First off, it is taking longer to vent the mains than it should so I am going to move the vents up onto nipples and add a second Gorton #1 to each main. Unfortunately, they are currently located at a 90 degree elbow where the dry return drips to the wet return (but I have no water hammer and they seem to be functioning).

My tube rads get screaming hot but I still have three column ones that are struggling. They all barely heat half way thru with the new vents (same with the old ones) even after the boiler has been firing for an hour and fifteen minutes and the boiler has shut off because the thermostat is satisfied.

I used an IR thermometer and have plenty of heat @ the gate valves and the sections that are heating are getting to 190+ degrees but the next one is about 60...? I even tried them ventless and did not notice a difference. I'm going to do a detailed time/temp analysis this weekend on each rad to see how long it takes them to get hot...

Right now I've got steam 7-10 minutes after the burner fires up and my mains are vented and hot about another 7-10 minutes later. The tube rads are hot within a few minutes and the rest of the column ones take a while longer but the three rebel rads still refuse to heat up. They are on two different mains, with different runout lengths, and one even has another radiator farther down on the same run that get hot all the way across...

Any advice on what I am doing wrong would be greatly appreciated. I can email a diagram of the layout and my calcs if anyone is willing to take a look. Any experts in the SE CT area?

Thanks.

Jeff

Terry in NJ

post the graphic of your system here

Also a photo of your boiler piping.

I'd suggest you try some heattimer varivalves on the column
radiators, they are supposed vent quicker when the other vents, see the pdf on their website. They helped for a while on our system(I am a homeowner too) which ended up needing lots of work thanks to the help received from this site.

Also you can try the "king vent" trick of adding a vent to the valve side of a radiator to vent the line leading to the radiator, the regular vent controls the temp of the radiator.

John Barba_6

Graphics & Calculations Uploaded

Terry:

I posted the diagram of the system and my Calcs... I will work on the piping shot but it appears good based on my read/pix in "Lost Art".

The Gorton's I've put on the rads are about the same as the varivents according to the flow tests in "Balancing Steam Systems" but I'll swap it out and see if there is a difference but doubt it. I did the no vent test and did not notice a significant difference.

About the King Vent... I'm getting plenty of steam (heat to 190 degrees plus) to the supply valve and relatively quickly but it isn't getting all the way thru the radiators.

Thanks.

Jeff

Terry in NJ

I've read that the radiators can be removed and flushed outside

there was a posting about getting muck out of them, maybe by snaking a small tubing in the vent hole and then adating to a garden hose.


Was the steam system not maintained?

John Barba_6

More Info...

Terry:

From what I have been told/learned from reading I have a two loop single pipe system with a dry return (comes in about 6' high and drops right before the Hartford Loop). I sized the vents to handle the volume of the entire mains & the dry return (they're located at the end of it) so if there are any more (which I haven't noticed) I would think that they would just be a bonus.

Pressuretrol is a PA404A set with a 0.5psig cut-in and with a 1.5psig cut-out. No issues with it stopping the boiler. Same for water.

I don't have any noteworthy noise (water hammer, etc), spitting vents, high-pressure or low water cut-offs - the thermostat turns the system off. It just takes what seems to be a long time to get the heat to the rads (new vents helping) but still having problems with the 3 rebel column rads.

I flush the low water cut-off regularly but no maintenance to the radiators aside from changing vents on my watch...

nicholas bonham-carter

radiator flushing

i think it's too dangerous to move the rads just for flushing[ could cause the nipple to leak], plus they are heavy!

why not get pipe fittings which will go from hos connection to the 1/8 in NPT. this can be screwed into the vent hole and using very light water pressure the blockage will be forced into the returns and then can be drained out in the boiler-room--nbc