Install Vents on Risers? Single pipe system

Clance

Someone offered a leaky valve solution on a post I read somewhere on the Wall - of replacing a radiator Valve with a T and putting a vent on top.

I live on the 2nd & 3rd Floor of a 2 family house. Each apartment has it's own boiler and single pipe/ dry return system. My system has not been used in about 5 years since the boiler rotted out. I have a new boiler being installed in a few weeks and thought I should repack all my valves (some are quite old judging by the wood handles) and maybe pick up some new rad vents to be ready to go after the new install.

I have never turned off any radiator valve. Not even when moving them one time when painting in the fall I stupidly left all the radiators off the valves and a couple weeks later the heat kicked on for the 1st time. I was in the shower... came out and couldn't see 2 feet in front of me. It was scary - At first I thought it was smoke/fire until I looks close saw all the water dripping down the walls and windows and realized the house was full of steam. It was crazy thick and I couldn't see a thing! Live and learn.

Back to my question - I have 4 risers up from the basement to my 2nd& 3rd floors. But for simplicity lets examine one - it is a 2" riser up from the basement. The 2" riser goes up through the 1st floor apartment dining room and is exposed. On the 2nd floor it branches off beneath the floor into 2 rads -dining room and living room rads back to back separated by a wall - and it becomes a 1 1/2" pipe that travels exposed through the 2nd floor dining room up to the 3rd floor where it branches off in beneath the floor and feeds 2 radiators - one in each bedroom- also back to back separated by a wall.

So a 2" pipe riser, maybe 9 feet tall feeding 2 rads on the 2nd floor then reduced to a 1 1//2" pipe riser, maybe 9' tall, up the 2 rads on the 3rd floor. About 18' total rise.

No vents anywhere on the entire system - the only venting for the whole system is through the radiator vents. I'm sure the pipe fitter will install some vents when re-configures the near boiler piping but I'm not sure what size or where or where. But I think its safe to say the near boiler piping will be vented.

Since I never shut a valve in my life, do you think its a good idea to take off the really old and, if I remember, leaky valves all together and replace with a T with vent on top to vent the riser.

If it's deemed a good Idea, would you do it to every radiator, or just two on the 3rd floor at the top end of the riser, or maybe just one at the top on the 3rd floor?

If it is deemed a bad Idea then I would be curious why you thinks it's bad.

Thanks!!! Rick in Winthrop MA

EBEBRATT-Ed

@Clance
I would put a riser vent on the 2" riser you posted about. In fact any riser with more than 2 radiators will probably work better with riser vents.

a smaller riser with only one vent may be ok with one vent if it stops on the second floor. Anything going to the third floor I would add a riser vent.

If the valves have wooden handles their old. I would replace them but you will also have to replace the spud and union nut on the radiator as they will not match up

Clance

@EBEBRATT-Ed
@Youngplumber
Here's a pic of one of the old valves with wood handles.
So - I get the idea - vent them but not too fast. however I don't know where to vent them... if the riser goes to the 3rd floor and feeds 2 rads up there but also feeds 2 rads on the 2nd floor...would you put a vent on one the 2nd floor, or would you put a bigger one on the 3rd floor,... or one a smaller one on each floor.

@EBEBRATT-Ed said Vent the risers but then you also said keep/change the valves... how would you vent the risers and keep the valves? Remember...I'm still learning...
Much appreciated!

GW

youngumber- you’re not supposed to regulate one pipe rads with the shut off valves 

ksd99

What is a riser vent?

Clance

@Youngplumber
@ksd99
@EBEBRATT-Ed

@Youngplumber - All the connection joints are buried between my floor and the ceiling down stairs so all I see is straight riser pipe capped with the valve. The only visible/accessible 90 is the turn up off the main 2 floors down cellar... if that's what you are asking.
But here's a pic of a setup venting the riser before the radiator. To incorporate something as shown would mean the radiators would skootch over a few inches. I would love to hear about other ways to vent an existing riser that terminates at a radiator valve.

Clance

@ksd99
I'm not a pipe fitter, just a home owner, but my understanding is that the riser is the vertical pipe that carries steam up and the riser vent is a vent added near the top of the riser that would allow the steam to displace the air in the riser quicker, thus steam getting to your radiator in less time because it's not relying on the small radiator vent to vacate the air from the riser pipe. Just my attempt at an answer

GW

Yes, parallel and one pipe are two different subjects. 

GW

Right on that was me a long time ago 

Neild5

Clance said:

@Youngplumber @ksd99 @EBEBRATT-Ed @Youngplumber - All the connection joints are buried between my floor and the ceiling down stairs so all I see is straight riser pipe capped with the valve. The only visible/accessible 90 is the turn up off the main 2 floors down cellar... if that's what you are asking. But here's a pic of a setup venting the riser before the radiator. To incorporate something as shown would mean the radiators would skootch over a few inches. I would love to hear about other ways to vent an existing riser that terminates at a radiator valve.   Another way to accomplish the same effect is to drill and tap the radiator and add a second vent.  You would want it to be low and right above the steam valve.  This would not require moving the radiator over.  This can be impossible in some cases for example my LR riser is about 2 feet from the corner add the radiator and there is just enough space to replace the vent.  
The new vent would be faster than the radiator vent, and would only be needed on the 3rd floor radiators. 

Clance

@Neild5
Thanks for suggesting that option - it seems like a great solution!

I found a few more options on an older thread... so here what I see as my option for venting existing system risers:
1 @Neild suggestion of tapping a 2nd vent into the radiator right above the valve connection
2 Tapping a vent into the existing external riser pipe just below the ceiling, so it's high and close to end.
3 Tapping the riser right under the valve and adding a nipple w/ elbow and vent.
4 replacing existing valve with T and put vent out one side and use the bull T w/ gate valve to feed rad.. skooching over rad.
5 Read somewhere - tapping a 2nd vent on the radiator opposite the valve side (similar to #1 but opposite)
6 Read in Dan's book - remove valve handle/internals, leaving valve body, and install vent in its place -(per Frank Gerety)

Love to hear what your preferences would be.. I seem to like the 1st suggest by @Neild5 or #6
Heres a few pics of some of the above mentioned options:

EBEBRATT-Ed

@Clance

Your picture is correct. You take off the existing old valve and put a tee in it's place. Then you install a new straight radiator valve (instead of the old angle valve you removed)

Vents go at "the end of the line" on the inlet to the last radiator that is fed (or as close as you can)

So vent the risers on the top floor that they feed. If they go to floor 3 vent on floor 3. If they stop at 2 vent on 2

If you have a riser to floor 2 and it only feeds 1 radiator I wouldn't bother with the riser vent, if the riser feed multiple rads I would and would vent all 3rd floor risers,

Keep in mind changing those valves and putting tees on isn't the easiest thing to do especially if you have not done it before.

Height is always an issue, usually end up shimming some rads up.

dabrakeman

I would eliminate #5 since that is not much different than putting a single huge vent on the radiator. Your goal is to get steam "to" the radiator quicker, not necessarily through it quicker.

Clance

@EBEBRATT-Ed
what would happen if I used the angle valve body with the stem removed and replaced with a vent like in the last picture above and didn't include a gate valve - then I wouldn't have to swap out the spud as I would be keeping the angle valve body and going right into the radiator and the position of the radiator would remain the same. Is that oK to do? As I said, never in the last 25 years have I turned off a valve. Do they make fittings/adapters that would fit where the stem was removed?
@dabrakeman
Thanks - I agree. From what I read one should vent the pipes fast and rads slow.

EBEBRATT-Ed

@Clance

No, no adapters. Possibly you could remove the valve stem and packing nut and drill and tap the right size for a vent....never done that

jhewings

I have been considering the #1 option for some 3rd floor radiators (1 radiator on each of 4 risers). The #3 option ( tapping into the riser below the valve is similar. ) Do you guys think a Gorton "D" is appropriate? Thanks, Jack

ethicalpaul

Yes I think it is. A Gorton #1 or D or a Maid o Mist of any size with the orifice removed. They’re all the same capacity