drilling/tapping new holes in mains for main vents

NYCDave

Now that our new boiler is more or less working, time to address the vents on the mains. There are two mains, each about 35 feet long, and at present each has one Gorton D vent on it... I am think of replacing each D with a Gorton #2. Does that sound about right? However, the vents are screwed right into the mains 2 inch pipe, and it looks like the hole and threading for a D and a #2 are different... do I just drill a new hole directly into the pipe, tap it, put in the new vent and plug the old hole? Seems like it might be hard to get access to the top of the pipe for drilling... Any suggestions/guidance? Thanks!!!

Hitzkup

Or find the first radiator, add a tee before it, reducer, nipple and install the main vent on top.

BobC

@Hitzkup I think you meant to say the last radiator that comes off the main?

@NYCDave Post a picture of that vent and how it's placed.

You really can't drill and tap a 1/2" hole in a 3" main, there just isn't enough meat for that size. You might be able to drill and tap a fitting like a elbow or T with a 1/4" hole if it's good and meaty and then adapt it up to the 1/2" fitting the gorton #2 needs. Keep in mind the vent gas to be more or less verical when it's installed.

Bob

Hitzkup

BobC said:

@Hitzkup I think you meant to say the last radiator that comes off the main?


Bob

Correct, first floor radiator, closest to the end of the main.

Another plus will be that main vent will be easily accessible.

Gsmith

Or, you can drill a hole in the main, of 1/2" or 3/4", at the horizontal or on an upward 45 degree angle and use a service saddle, like model 101U from Romac Industries (www.romac.com), available in 1/2" and 3/4" outlets for many main pipe sizes from 1-1/2" upward. For steam service be sure to order the optional EPDM gasket (the normal Buna-N rubber gasket is not rated above about 180 deg F). These saddles are very reasonably priced (<$40 or so with the optional gasket), you will have to order from a pipe supply company, see the Romac website for distributors. I found it very easy for a homeowner to add large openings in older main pipes without taking the old fittings apart. Even if installed horizontally (with a 90 deg elbow upward and pipe nipples to install the vent on) I had not water hammer because very little steam is needed to close the vent and stop the condensation.

NYCDave

Thanks guys for all the suggestions! I love the saddle contraption, that is awesome and I may do that...

How bad would it be to just use the existing hole (I guess 1/8 or 1/4 size) with a short nipple and a reducer to attache the #2 Gorton? Would the smaller diameter nipple slow the steam down too much?

JUGHNE

1/4" nipple will pass enough for a Gorton 2.
1/8" is a little small.

That small nipple may be screwed into bushing......that could get you up to 1/2 or 3/4" if you can get them removed.

New England SteamWorks

Not that big of a deal to do it right and permanent with a proper tee with a 3/4" bull.

I am a big believer in" "If a thing is worth doing..."