Measuring Threaded Female Things

[CardsFan]

You do realize there are LEFT and RIGHT hand threads don't you?

And PEX tubing comes in RED and BLUE??

There, I went and did it

-ERD50

Well, I guess you have made Harley's point about this being a safe place, but maybe not too sane.

 

[ERD50]

Well, I guess you have made Harley's point about this being a safe place, but maybe not too sane.

I resemble that remark!

-ERD50

 

[OldShooter]

I am more afraid with him doing gas piping not knowing pipe sizing or thread style. If he uses a flare adaptor thinking its a pipe thread, it will leak. Yikes!

This.

Gas is dangerous and LP is especially dangerous. Covering your floor with a pool of LP gas is a good way to get dead.

 

[LOL!]

You got a permit for that?

 

[target2019]

When you need to make connection, go to orange or blue store. Start wandering up and down aisles, and locate the bay where extension cords are. Ok, that's the wrong place!

Rather, search internet for lowes gas range hookup. If a lot of porn comes up, scan your computer. Or call a computer guy (maybe lady).

Instead, have gas range delivered by store. You may get lucky, and the guy on truck will toss a kit your way, for a twenty. The kit comes with correct dope and leak detection fluid.

I also purchased an Electronic Gas Leak Detector. Had a problem with HVAC gas hookup once...

 

[travelover]

All joking aside, I bought a set of digital calipers (often on sale at Harbor Freight for ten bucks) and use them along with internet resources for actual dimensions to figure out what I actually need. The calipers are especially useful for round parts.

 

[gerntz]

If you have a 1/2" pipe, you never want the flow cross-section diameter to go below 1/2". So the threaded parts associated with 1/2" pipe will always be quite a bit larger than 1/2". They need to account for wall size, threads, etc.


-ERD50

Nope. The threads of all "1/2" pipes match and the outside diameter of the thread matches closely to the pipe's outside wall diameter. Net, if the pipe needs to withstand higher than standard pressure at same nominal size, the wall gets thicker such that the pipe I.D. gets smaller & its flow capacity is reduced at that same nominal size.

Scroll down this chart that shows the I.D. being reduced for higher pressure ratings at the same nominal pipe size.

https://ipspipe.com/wp-content/uploads/2015/06/Pipe_pressure_rating.pdf

Note that if you want about the same I.D. as 1/8" Standard Schedule 40 pressure rated pipe you need 1/2" Double Extra Strong Pipe.

1/2" Std. Pipe has about same I.D. as 1" Dble Ex Strg.

 

[latexman]

Here is a handy chart, showing OD, ID, and thread count for various sizes of standard wall (schedule 40) NPT (National Pipe Thread) pipe
https://www.engineeringtoolbox.com/ansi-steel-pipes-d_305.html

This one shows the variation in wall thickness and ID, depending on the schedule
http://www.tiogapipe.com/assets/files/pipe-chart.pdf

For each size pipe, the OD is constant. Only the ID and wall thickness vary based on the pressure rating.

^
The real winner!

https://en.wikipedia.org/wiki/National_pipe_thread

 

[ERD50]

Nope. The threads of all "1/2" pipes match and the outside diameter of the thread matches closely to the pipe's outside wall diameter. Net, if the pipe needs to withstand higher than standard pressure at same nominal size, the wall gets thicker such that the pipe I.D. gets smaller & its flow capacity is reduced at that same nominal size.

Scroll down this chart that shows the I.D. being reduced for higher pressure ratings at the same nominal pipe size.

https://ipspipe.com/wp-content/uploads/2015/06/Pipe_pressure_rating.pdf

Note that if you want about the same I.D. as 1/8" Standard Schedule 40 pressure rated pipe you need 1/2" Double Extra Strong Pipe.

1/2" Std. Pipe has about same I.D. as 1" Dble Ex Strg.

Thanks, I was surprised to see that. Based on the whole concept of the connectors on a 1/2" pipe not constricting to less than 1/2", I was under the impression (and thought I'd seen it that way, but I guess not), that the thicker walled stuff increased the OD, not decrease the ID.

Plumbing stuff makes less sense than I thought!

-ERD50

 

[gerntz]

Thanks, I was surprised to see that. Based on the whole concept of the connectors on a 1/2" pipe not constricting to less than 1/2", I was under the impression (and thought I'd seen it that way, but I guess not), that the thicker walled stuff increased the OD, not decrease the ID.

Plumbing stuff makes less sense than I thought!

-ERD50

When talking pipe size, they are talking thread & wall O.D. dimensions, not I.D. Otherwise, threads & O.D.'s for different pressure ratings of same size wouldn't fit each other , and thus you'd have 4x the number of O.D.'s for the 4 pressure ratings than exist already.

 

[Walt34]

Are you using pipe dope? Is it dope or tape specifically approved for gas?

Both used to be when I was working on furnaces & water heaters but that was many decades ago.

Now that the thread has turned to the subject of gas it may start to stink.

 

[aja8888]

If you want a real frustrating experience, go to HD or L and try to buy a 1/4" NPT pipe thread tap.

 

[Curmudgeon]

Both used to be when I was working on furnaces & water heaters but that was many decades ago.

White tape, at least the types with which I am familiar, are OK for liquids, but not gas, as they are porous. (They are actually Gore-Tex.) You need yellow tape for gases.

 

[samclem]

Both used to be when I was working on furnaces & water heaters but that was many decades ago.

I have usually used the thick yellow tape when connecting iron pipe for natural gas, but had a >heck< of time getting good seals when I installed an LP furnace last year. A plumber friend recommended RectorSeal 5 sealant for these joints, an after I used it I had no more problems. Now I use it whenever I'm working with natural gas or propane, it's good stuff. It's not available everywhere, but it's not too hard to find.

 

[TromboneAl]

I used the yellow tape. A guy from the gas company came and checked things out for $64.

I think plumbing (and gas fitting) is like making sausage. When you see how things work, you lose confidence and expect failures. For example, I'm confident in the flare fittings, but the tape doesn't seem reliable enough.

 

[GravitySucks]

At least you mods don't need to worry about this one turning political!


:

Carter should have followed through with the metric conversion more forcefully.

Al - There is no such thing as a one trip to the hardware store plumbing job

 

[CardsFan]

Al - There is no such thing as a one trip to the hardware store plumbing job

Well said.

 

[zedd]

So disappointed.

Thought that this would be a thread about plumbing and not about the threading of plumbing.

 

[CaptTom]

Al - There is no such thing as a one trip to the hardware store plumbing job

I really felt like I hit a milestone of sorts the other day. Below-zero temperatures, through my own fault I ended up with a burst, frozen pipe. No problem, break out the plumbing tool kit, screw together the torch, cut out the old pipe and replace it with one I had "in stock." No trip to the store.

Along the way, I found a slow leak in another part of the system. One of those automatic vent "air cans" which always seem to leak after a few years. No problem. While I've got the tool box out, I'm pretty sure there's a new, manual air vent valve (the kind that will never need to be replaced) in there somewhere. Yup. Pop the old one out and the new one in. No trip to the store.

Made a note to replenish my stock next time I'm at the big-box.

Admittedly, another project (running a new wire for a smart, WiFi thermostat) took a week, two new tools and several trips to the store. But next time, I'll have the tools!

 

[gerntz]

Carter should have followed through with the metric conversion more forcefully.

Al - There is no such thing as a one trip to the hardware store plumbing job

Agree with last sentence.

I understand pipe sizing is uniform between ANSI and metric meaning pretty much globally. Just use different nominal names such as 25mm vs. 1".

Think about global oil drilling equipment/refineries/transport tankers & filling/unload lines. Going back 25 years & working in Germany briefly on a project, a German engineer told me that they used inch named pipes commonly. Seemed real strange that they did.

 

[FIREmenow]

Al - There is no such thing as a one trip to the hardware store plumbing job

If local big box store, I usually buy one of every close size to be sure and bring home a big bag. I use what fits for my project and then go back and return everything else. Saves on gas (a bit) and time.

 

[travelover]

If local big box store, I usually buy one of every close size to be sure and bring home a big bag. I use what fits for my project and then go back and return everything else. Saves on gas (a bit) and time.

Good advice - I buy anything and everything that I might need, because I always seem to damage the next piece (or two) adjacent to the problem and need to replace it as well.