threadolet job for welder, or just drill & tap a hole?

[Deleted User]

To add a Gorton #2 main vent to a steam return pipe, I need to somehow put a 1/2" threaded hole in it. The existing hole on a 90 degree elbow is only 1/4" and does not provide enough venting with its Gorton #1 screwed into a 3/8" adapter.

Is it safe to just drill (with some special bit?) & tap (hand-turn a threading tap device) and mount a Gorton #2 on a nipple directly to the 2" pipe, or do I need a pipe welder to add a "threadolet" for added stability and safety? Or should the vent be mounted on a T and welded in place? Any good pipe welder in northern/central NJ for such a job?

johnlobb

As a long time pipewelder and steamfitter, a welded threadolet is much safer. Call your local pipefitter/steamfitter union for a competent welder.

David Nadle

According to Gerry Gill's data, an open 1/4" pipe vents faster than a Gorton #2, so you may want to try with another adapter before you drill a new hole.

[Deleted User]

Did Gill & Pajek say this in their Balancing Steam Systems book? I definitely need to buy it if so. If they're right, the bottleneck is not the 1/4" hole in my main pipe but the Gorton #1 I've mounted on a 3/8" adapter to it. By this reasoning, if I can adapt a Gorton #2 to it, I could vent faster without having to drill a larger hole. It's hard to believe but cheap enough to test. Thanks for the idea.

Abracadabra

I don't see data for 1/4" open pipe in their book. I do see 1/8" and 1/2". If I had to guess, I'd say 1/4" would vent a bit over 3cfm at 3oz. open 1/8" vents at 2.5. a gorton #2 vents at 2.2

for flexibility in venting I'd weld a 3/4" nipple onto an appropriate hole on the main and reduce it down if you had to. With the pressures we are talking about for steam, a threadolet isn't really needed. I've just done a saddle cut on a nipple and welded it directly to the main.

Not my picture, but just an example.