Steamhead..Help with my Main Vents Please

Steamhead (in transit)

let us know what you find.

Jeff_17

Steamhead...Please help me with my Main Vent sizing

Steamhead,

I have a main that I need PROPERLY vented to help heat radiators on my third floor...It is a one-pipe steam...and ONE main out of the two takes longer to heat and consequently the rads at the end of the line way up on the third floor. The Main is 19.5 feet of 2.5" main until it turns into a 1.5" dry return...the dry return's length is 20 feet, and the main vents I have now are on a "t" just as it heads down into the wet return: Two Dole #1's

The rad risers get hot up to the rad without too much of a problem...and then the rad is slow to heat...even the first few sections. One, column style, is pitched enough to drain the condensate. The one in the bathroom is a wall-mounted circa 1935 and has pretty much a level pitch...no water hammer. This one heats VERY SLOW...the riser gets super hot to the valve...and then the rad takes its good old time. I would appreciate your insight....

Steamhead (in transit)

Are those

the only two slow rads you have? If so, you may need to increase their vent sizes.

I'm not familiar with the Dole #1- Can you post a pic? How long does it take for the main to get hot to the vent location (measured from the time the boiler starts sending steam into the system)?

Jeff_17

Those are the only two....

that heat that way. I have a Maid o Mist (Similar to the Gorton) size D on the column type.

On the wall mounted, I have a Maid o Mist size C.
Could it be they are venting too fast...causing too much condensate to pool and steam to go sour?

The DOLE #1 looks and acts like the Gorton #1 IDENTICAL to it! The main takes about 5-6 minutes to get hot to the end before it turns into the wet return

Steamhead (in transit)

Strange

with all that venting they should be getting hot quickly. Are the mains insulated? Is the boiler sized properly and firing properly?

Jeff_17

The mains are

insulated, the run-outs to the risers still have some of their original asbestos covering. The other is covered with the fiberglass.

Why does the darn riser heat GREAT and fast until it reaches the valve..then seems to fizzle out? Do you think they can be venting too fast? I have not tried to slow them for fear they would NEVER heat!

Steamhead (in transit)

Check

the shutoff valves to the rads. Pull the rads and look inside. Sometimes the discs that hold the washers break off inside, blocking the flow.

The riser would still heat, since steam is lighter than air it will rise on its own, as far as the valve.

Jeff_17

I already

checked on that! That supply valves and stems are fine. I think I read that in Dan's book, so that was an option I went for in the beginning....

The wall mounted one gives me the most trouble. The column one is heating, but not as fast as I want it to to heat the room. The wall mount one give BARELY any heat past the first 2 inches....I did measure the mains....do you think I can use a Gorton Number 2 and see what happens?

Steamhead (in transit)

Now check

the EDR of the rads against the sizes of the risers that feed them. They just might be too small....

Also, does the boiler shut off about the time those rads quit heating?

thfurnitureguy_4

just a thought Try removing the vent on the slow rad and see if it heats

Jeff_62

Steamhead...The EDR of the wall

radiator is 10....and the riser is a 1.5 in diameter.

I noticed today that the radiator's riser gets hot fast right up to the valve. The valve gets hot right until the union/nipple that goes into the wall radiator, then the rad stays pretty much cold EVEN with the vent removed...only a slight bit "WARM" on the first "column" of the first section.

Jeff_62

the boiler does

not shut off when the rad quits heating. It is still steaming. I am going to have to remove the rad and check that valve again. Maybe it is time for a replacement or to see if there is sludge in the way? I checked last fall and basically saw nothing.

Drod

radiators not heating

I'm a novice and had a similar problem. After trying lots of things (checking valve, pitch, vent, etc.) with the one upstairs radiator that wouldn't heat and had very similar characteristics to the problem described here, I finally gave up. About a week later I went back into the room, and looked at the radiator and valve/shut off again, and finally realized that the shut off valve assembly looked different than the rest in my house. The assembly didn't have the "big belly" part that the others had, but rather it looked more like a standard water type shut off valve. I replaced it with the "big belly" type, and you've probably guessed what happened-it heated up just like the rest. Apparently someone (maybe a previous owner / novice) had replaced the shut off with the incorrect type. Just a thought.

thfurnitureguy_4

Same thing here, they used a gate valve and the end cranked off the shaft leaving the gate closed and stuck. The handle still turned like it was working!