I'm preparing to do a service that requires a 16 - 17' mast(The property slopes away from the street and the POCO's lines are on the opposite side. The meter pan's location will be on the back side of the garage peak, so I'll need to project far enough above that so I'll be able to have a 18" drip loop.). I have a 7' piece of 2 1/2" gal and need to get that threaded to be used as the bottom piece. I spoke to a master plumber and he said that most plumbers only go as far as 2" pipe. The orange box store said the same. Any suggestions? pete
You need to get up close and personal with someone at a company that regularly works with larger size pipe and has the equipment to thread that pipe.
This is a good contact to develop anyway for all sorts of reasons (like this) and the occasional smaller job a regular customer of theirs needs but they don't want to mobilize for. May be right up your alley.
Design-Build isn't supposed to mean design *as* you build.
I recently needed some 4" threaded pipe .... the plumbing supply house had no problem providing me with the pipe I asked for, cut to length, and threaded. Since pipe commonly comes in 20ft lengths, they ought to be able to make a piece for your mast - if you can transport it.
BTW, it may be a fine point, but I don't think a service mast need be made of 'listed' material. Conduit, yes ... but the code is silent as to the mast.
Failing a friendly supply house, any machine shop with an "engine lathe" ought to be able to cut the threads into anything up to 4" OD.
Rigid makes an attachment gear for threading 2-1/2 thru 4" galvanized rigid. Trade slang is I think hog leg. I just now walked into my shop to look at the model number. 4P-J . You use it in conjunction with a Rigid 300 and a porta pony threader. A new one would be way too pricey if you only are using it this one time. Some hardware stores have a stand up threader that threads up to 4" for threading pipe they sell. Call around.
My first reaction was to put the "bald" end up top, but the AHJ wants the smaller length closer to the meter pan. I believe that his reasoning is that you'll have more meat attached to the house before it goes through the roof. Two clamps and then through the roof (in the 7' of pipe) vs. 1 clamp on the 3' (leaving the 3' beyond the roof out of these calc). Also, I guess since the coupling is further down you'd have less strain on it. It's an 84' drop from the pole to the house. Thanks for all the suggestions.