venting riser

Fred Harwood_2

Describe your main and its venting (what vent, what size and length main, insulated or uninsulated).

Pete_24

still looking for advice

Any guidance on the best way to vent a steam riser would be greatly appreciated. This is a riser that feeds a 2nd and 3rd floor radiator that I need to get the steam to faster than I am able to get with vents on the radiator. Unfortunately this riser is the last feed off my cold-side main.

Pete_24

Hot main - 26 ft (3 in. main) Vent: (1) Gorton 2

Cold main - 39 ft (2 in. main) Vent: (1) Gorton 2

Header is a few feet of 2 1/2 & 3 in. IPS.

Each radiator is vented with Gorton vents based on their EDR size with minor adjustment up or down based on distance from the main.

Both mains heat up pretty close to one another (cold takes slightly longer, but not much), and the boiler is sized properly.

I am not happy with the amount of steam making its way to the two furthest radiators, both fed off of the last riser on the cold main. I was thinking that if I could vent this riser quickly that it would increase my chances of getting steam to these radiators quickly (better than I am able to do with an oversized Gorton D on them and the Gorton D ends up causing uneven heat with the two radiators sharing the riser).

All the mains are insulated and I have also insulated the exposed pipes for the riser.

headerless

Similar problem with my house

I have two 50 foot 2" mains and a 30 foot 1 1/2" main -- based on the info from Dan's book and Steamhead I have been adding a lot of vents. Now, the raditors upstairs are slow to heat (and they are at the ends of the mains) so I am adding Gorton D's at the top of each riser mated w/ 1/4" street elbows. I am pretty sure this will work.


50' mains now have Hoffman 75 + 4 Gorton D's at end, 2 Gorton D's in the middle per main.

30' main now has Hoffman 75 + 2 Gorton D's at end, 2 Gorton D's in middle.

All of the vents sit on risers. I am thinking of adding strainers to keep them from getting plugged, and changing the 1.5" header to a 2" header (based on the Hoffman Guide to Steam Systems: "2 inch minimum for headers")

Each of the 4 risers has a Gorton D

Total vents for mains and risers = 3 Hoffman 75's + 20 Gorton D's. Please note I am using a lot of Gorton D's because I ran across a box of 30 new ones in wrappers for $90. I believe 2 Gorton D's flow the same as a Gorton #2.

I will let you know whether the Gorton D's on risers help. Gotta vent those mains fast!

Fred Harwood_2

cold main?

A 3-in main holds many times more air per foot than a 2-in main does. I'm tempted to suggest that you try a Gorton #1 vent on the 3-in, or to 2 #2s on the 2-in (total of 3 #2s).

Also, how many minutes between your boiler on and then on again?

You can vent a riser, but first see if you can balance those mains, quickly.

headerless

balance is important

I agree with Fred on balance. Lat year I had the same venting on the 30' main as the 50' mains and the radiators off the 50' mains were very slow to heat while the radiators off the 30' main heated quickly.

I don't see any harm in venting risers. It takes very little time to tap the risers -- just start with a small bit and then move to the right size bit for the tap.

Pete_24

Steamhead, what do you think about what vents I should have on my mains? (noted above in the thread?)

Pete_24

What's the right way to drill in to the riser / thread it, tap it, etc so that I don't destroy a pipe that has been in the house for 100+ years that I can't re-run?

headerless

tapping pipes

I hesitated but then went for it. I think I have 3 threads in the holes I tapped:

1) Mark where you will put your hole. Make sure you have clearance for the handle that holds the tap without cutting a hole in your ceiling (this is important)

2) Chuck a small titanium bit (~ 1/16") and drill a hole. The small bit won't wander.

3) Chuck a medium size bit (~1/4") and make your hole bigger.

4) Chuck the size bit the tap calls for and make the right size bit.

5) Tap the hole but don't use cutting oil -- it is not necessary for iron. Also, note the tap is slightly tapered and the more you spin the tap the bigger hole your are going to make. Since you are only cutting 3 threads making a big hole is not good -- sloppy fit.

6) If you screw up you can make a larger hole and tap 1 size up and use a reducer.

If you weld you can weld on threaded inserts that will give you more threads.

LarryC

What ??????

Tap the hole but don't use cutting oil -- it is not necessary for iron.

News to me. If you want the taps to last, I would definitely recommend using a tapping fluid.

Use a **** punch to put a small divit where you want the hole. That also helps to keep the small bit from wandering.

Larry C

Steamhead (in transit)

Actually

it takes four Gorton #D vents to equal one #2.

Also, you want all your venting capacity at the end of the main. The way you have it now, steam gets to the middle quickly then slows down for the second half of the main.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Steamhead (in transit)

First

add a second Gorton #2 to the end of the long cold main. If you still have issues on that riser, install a D on it by drilling and tapping. Here's a pic of one we did.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Pete_24

Out of curiosity, why did you choose to put your D there on the riser vs. up at the top under where the radiator union is?

headerless

Question for Steamhead

I still belive 2 Gorton D's = 1 Gorton #2. My "data" is this chart from Heat-timer:

www.heat-timer.com/literature/PN056082.pdf

Can you point me to data that says four D's = one #2?