black pipe assembly technique

[CHH]

But the 48" steel wrench almost tightens the fittings itself..
Of course, it does weigh about 50 or so lbs...LOL

Hmmm, maybe you're thinking of the 60" which weighs 50 lbs. I never had to use one but saw one once in a machine shop. The 48" is 35 lbs. Of course at the end of the day it weighed about 200 lbs and took two men and a small boy to haul back to the truck....

When it gets to the point that the big iron is needed nothing is easy 'cept getting people hurt.

 

[Frenchie]

60?!? I probably couldn't even lift a 48" wrench!

My 24 & 18 are aluminum, if that gives an idea...

 

[Sponsor]

 

[CHH]

They wouldn't let us use aluminum. Too easy to break.

 

[Molo]

I have to connect a gas meter bar to the existing gas line about 2 feet from the meter (through the wall, inside the house). The gas company has told me that they will pressure test before they will pressure test before they put the meter on, and allow service. This is an old home, and some of the black iron is showing rust and deterioration.
Should I be concerned about tons of leaks showing up when the gas company pressure tests it?

TIA,
Molo

 

[CHH]

Warning Sea Story: Molo's question reminds me of a problem we had on an offshore installation. A piece of equipment which applied a vacuum to fluid had failed and it was going to have financial penalties for my company. The guys who were supposed to operate and maintain the device couldn't figure out what was wrong and since I happened to be onsite they asked me to take a look. I read the manual then went out to look at the misbehaving iron. This darn thing had a black iron line that ran from a vacuum pump to a vessel where the fluid and vacuum were contacted. The black iron had been painted except for the threads. The threads were quite rusty. The vacuum pump seemed to be operating so I said R & R the black iron. One of the men grabbed a wrench and started breaking down connections. After he loosened a union, I said "watch this" with the intention of just kicking another connection loose. Instead of loosening the connection, it just broke. The threads were basically rusted through.

Moral of the story: if the pipe is exposed to the elements and hasn't been maintained then there may well be a problem.

There is nothing wrong with pressure testing the pipe before the gas co. shows up. A simple close visual inspection after steel brushing the rusty spots may be enough to tell you that the pipe is good or bad. You really don't want to have to call the utility guys to come back.

 

[Frenchie]

Your comment about "they" deciding aluminum's too fragile, is starting to make sense. What's your background, exactly?

 

[GrumpyPlumber]

Your comment about "they" deciding aluminum's too fragile, is starting to make sense. What's your background, exactly?

He's Commercial/industrial...as far as I'm concerned, the really interesting stuff. Get 'im talkin'.

 

[CHH]

Your comment about "they" deciding aluminum's too fragile, is starting to make sense. What's your background, exactly?

Well, describing my background "exactly" might be a bit tedious. Let's just say that I've spent about 27 years working in the oil patch at every level from field grunt to engineer to teaching/mentoring. After the first 5 years in the field and schooling, nearly every year has been different because I get bored and change positions reletively frequently. Right now I'm self employed as an analyst and designer.

The DIY projects have been fun because I actually get to produce something rather than just write reports and specifications. I found this site after the boiler replacement project but have a bathroom renovation project coming up so thought I'd hang out awhile an learn what I can.

 

[gtmtnbiker]

I have another question on black pipe assembly.

Let's say that you are trying to put a directional T on a line and tightened it such that it won't move any more (without using a cheater) but you still have another 180 deg to go.

Can you take off the fitting, reapply teflon tape & pipe dope, and reuse the fitting at a different starting point? Let's say that in your first attempt, you started the fitting at 0 deg vertically (same position where you want to end up) and your first attempt was 180 deg away from where you wanted to end up. Could you put the fitting on at 180 deg vertically (The T pointing to the floor) and have it end up where you want it to be? Does the starting position have any effect on how the fitting will end up given the same number of turns? Or because of the way the threads are cut, there can be only one place to get a fitting on?

 

[hj]

tight

1. Wrench size is a subjective thing. Fire sprinkler fitters use 10" and 14" wrenches, but the first thing they do with them is add about a 12" conduit extension to the handle.
2. If you need a 48" wrench, then my 36" compound might be a better choice, especially when taking joints apart.
3. Terry, where did you get my picture to insert in that previous reply?

 

[CHH]

I have another question on black pipe assembly.

Let's say that you are trying to put a directional T on a line and tightened it such that it won't move any more (without using a cheater) but you still have another 180 deg to go.

Can you take off the fitting, reapply teflon tape & pipe dope, and reuse the fitting at a different starting point? Let's say that in your first attempt, you started the fitting at 0 deg vertically (same position where you want to end up) and your first attempt was 180 deg away from where you wanted to end up. Could you put the fitting on at 180 deg vertically (The T pointing to the floor) and have it end up where you want it to be? Does the starting position have any effect on how the fitting will end up given the same number of turns? Or because of the way the threads are cut, there can be only one place to get a fitting on?

NPT only has one thread per connection so there is only one starting point. In other words, it doesn't matter where you want it to start, it can only start where the thread starts.

If you are old enough, "threads" are just like "grooves" on a record album. There is only one "groove" per side and it is continuous.

 

[Molo]

I have to connect a gas meter bar to the existing gas line about 2 feet from the meter (through the wall, inside the house). The gas company has told me that they will pressure test before they will pressure test before they put the meter on, and allow service. This is an old home, and some of the black iron is showing rust and deterioration.
Should I be concerned about tons of leaks showing up when the gas company pressure tests it?

TIA,
Molo

The results are in. I did the repipe out to the meter. The gas guy came out and put 3lbs. on it. He said it normally is under only ounces of pressure. There was in fact a leak. It was at an existing fitting that I hadn't messed with. It was where `1/2" black iron went into a galvanized coupling. I put a cap on it, he tested it, and it held. Is 3 lbs. normal for a gas company pressure test?