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The world of pipe fittings

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Re: The world of pipe fittings

#201

Post by mgarfias »

pengaru wrote: post #166
mgarfias wrote: post #138

Earlier quoted context omitted.

A small quibble: the tape don’t seal. It’s a lubricant for the threads wedging together to seal. For a REALLY good primer on the subject, read Carrol Smith’s _Nuts, Bolts, Fasteners and Plumbing Handbook_ (aka Screw to Win).

> For a REALLY good primer on the subject, read Carrol Smith’s _Nuts, Bolts, Fasteners and Plumbing Handbook_ (aka Screw to Win). +1 for anything by Carrol Smith Back in my gearhead days Engineer To Win was a near constant fixture next to the toilet.

I had no idea he lived nearby when I was in HS (also Gurney’s shop was within biking distance, also didn’t know it).

If I could go back I’d blow off all the dumb shit I did and go ask to push a broom all day just to hang around race cars and learn.

Re: The world of pipe fittings

#202

Post by ethbr0 »

hilbert42 wrote: post #63
SaintGhurka wrote: post #45

Earlier quoted context omitted.

"combination of Hessian/burlap jute-type rope (of which there is always some lying around in my workshop) and linseed oil based paint." Could you explain that? How do you seal pipe fittings with rope? Edit: found an explanation. TIL that you can use the fibers just like tape and wrap the threads.

Perhaps if I'd used the proper name what I said may have been clearer. The correct name is hemp rope or plumber's rope but I don't often have that around (not being a plumber) so I use the next best thing available Hessian fabric or its rope equivalent). Here are some photos: https://www.bunnings.com.au/enduraseal-1m-plumbers-hemp_p012... https://waropes.com.au/twines/plumbers-hemp/ You wrap the hemp fibers around th…

>> [...] has been specifically designed and manufactured to suit the Australian market and conditions.

That's some hearty stuff, then!

Re: The world of pipe fittings

#203

Post by hansvm »

noNothing wrote: post #193
joshuaheard wrote: post #180

I had to learn the arcane world of pipe fitting sizes working with pneumatics for a scuba equipment project. It is extremely confusing. Unfortunately, it can have fatal consequences. In a recent story, a scuba store employee used the wrong size fitting on a 3,000 psi scuba tank which shot out and killed them. Seeing that American can't even adopt the metric system, I have little hope for a clear international standar…

All Americans completely understand the metric system. We can convert anything to anything in our heads. By the way, we all speak a dozen foreign languages fluently, just choose not to. It is because we are so humble that you do not know this.

I was with you till you asserted we only speak a dozen languages.

Re: The world of pipe fittings

#204

Post by ethbr0 »

johnwalkr wrote: post #164
mannykannot wrote: post #35

Earlier quoted context omitted.

What do you think of the advice that it is acceptable to use a tapered male thread in a straight female one? My guess is that if you do that, you have at best one turn of the thread helix holding them together and providing a seal (and perhaps you would be trusting in nothing more than the tape jammed between the threads if you used ten turns of it!)

I don’t think it’s acceptable. Maybe works in pinch to get through a weekend but I would always replace it with a proper fitting. Plus if you damage the female threads or o-ring seat, you’ve made a much worse problem for yourself.

It's probably a commentary on the idea that the tapered male diameter is its max diameter(?), versus straight is throughout.

Consequently, a tapered male will fully screw into a straight female, albeit with gaps between the threads at the deep end of the socket.

Whereas a straight male will at most only screw the first few threads into a tapered female, leaving most of the male hanging out.

Re: The world of pipe fittings

#205

Post by hattmall »

jkqwzsoo wrote: post #9

In case anyone from the US reads this, BSPP and BSPT fittings are rare and incredibly frustrating here, as our NPT (National Pipe Taper) threads are different and the selection of BSP(P/T) fittings is extremely poor in comparison. Also, I work with NPT fittings quite a lot: > For what it’s worth, I tightly wrap the tape 10 times round the male thread and get an enraged mountain gorilla to tighten it up. This is a WTF…

The real pro-tip is not to use tape at all. Instead use pipe dope or joint compound, it's cheap, easy, and better in every possible way. If you only have two do one or two very low importance joints, like a showerhead then tape is fine. But for anything serious use the joint compound. If you are doing a lot of work it's absolutely a game changer.

Re: The world of pipe fittings

#206

Post by georgeoliver »

CamperBob2 wrote: post #177
georgeoliver wrote: post #93

Earlier quoted context omitted.

I had a funny experience a week ago. One night working on a hobby web project it took me three or four hours to debug something, I finally got to bed around midnight thinking "boy, programming is hard". The next day at work we had to find a broken heat wire in a tiled bathroom floor, running 1000 volts through the wires to try to fuse the broken wire, then heating the floor up and searching with heat-sensitive paper…

Time-domain reflectometry. To Google it is to love it.

Very cool! The tech did have some device that could measure the distance to the fault when tied into wire upstream, but I'm not sure if it was a TDR, I think he was making more rule of thumb calculations based on the characteristics of the wire. I would say though that between his voltage box, amp box, and general test tools he had the coolest tech on the jobsite in general.

Re: The world of pipe fittings

#207

Post by midhhhthrow »

One thing I’ve learned the hard way is that you need those little gasket seals on the inside to avoid a leak but if you over tighten the connection with a gasket inside you can actually get a leak just from over tightening it!

Re: The world of pipe fittings

#208

Post by mildchalupa »

cmclaughlin wrote: post #44
blincoln wrote: post #12

I've helped out with some plumbing work in an older house, and it's pretty fascinating to see the progression of technologies. 100 years ago, most drain pipes in the US were massive cast-iron pieces with no threads at all. They were mated together, then the joint was filled with a compound called oakum. To really hold it together, the plumber would pour molten lead on top of the oakum. Just taking that stuff apart is…

> I like PEX, but I know opinions vary What’s not to like about PEX?

Nearly all homes built in Tucson AZ had a type of plastic that degrades over time resulting in catastrophic failure eventually.

Re: The world of pipe fittings

#209

Post by c_o_n_v_e_x »

mildchalupa wrote: post #27

The Teflon tape is only to be used as a friction modifier as NPT and other tapered threads seal on the threads. Reduced friction means that you can get enough load to deform the metal threads and create a seal. Be careful to not add tape to the first 2 threads as small pieces of Teflon tape can break off and get stuck into valves and things within appliances causing them to leak. There is nothing wrong with pipe dope…

In a previous life, I managed a team of instrumentation and tubing fitters at a new chemical plant that was being built. Some of the tubing for the process analyzers (chromatographs) had to be redone as they used PTFE tape on the fittings which was being detected by the GC.

Re: The world of pipe fittings

#210

Post by mildchalupa »

jaggederest wrote: post #129
Scoundreller wrote: post #110

Earlier quoted context omitted.

More recently, beyond pH control, cities are doing orthophosphte corrosion control. Nearly universal in UK but hit and miss in other places. https://www.haldimandcounty.ca/wp-content/uploads/2018/07/Or... A big source of lead can be recently sweated copper lines (takes a while for the corrosion control to coat it), but lead solder isn’t supposed to be in potable use anymore. And old fixtures! Even newer “lead-free” f…

Yes I've found it's very frustrating looking for "genuinely zero lead" brass and bronze. Almost all scrap has lead in it to some degree, and even new metal often has a trace.

Lead free brass is still 0.2% or less. Mitsubishi makes it. "Eco brass".

I'm not sure it's brass anymore without the lead.

Why does it seem that the better a material works the worse it is for humans.

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