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The world of pipe fittings

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Re: The world of pipe fittings

#241

Post by dsfyu404ed »

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…

Your comment reeks to high heaven of textbook engineer. The practices you advise do not survive in a world of bottom dollar commodity pipe fittings.

Everyone with dirty fingernails knows that 3-4 wraps is a pretty good rule of thumb for fittings that are meant to go together and you need more when you're mix and matching BSP and NPT threads because you have a larger leak path to take up.

Nobody bothers stocking multiple widths of tape. That only makes sense in a production environment where you're only ever working with one size and can build to it.

In a pinch you can "augment" things like compression fittings with tape on the OD of the ferrule.

Re: The world of pipe fittings

#242

Post by dsfyu404ed »

kennend3 wrote: post #108
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…

As someone who is NOT a pipe fitter but lived with one for many years.. It was odd reading this and I'm glad someone like you responded to correct things. > 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. Again, not a pipe fitter but this just screams "WRONG". If someone needs to use that much force to tighten it up, one can only assume…

>"Pipe dope is generally stronger seal than Teflon tape, which is why plumbers and other professionals use it rather than tape for seals that are permanent."

They use it because it's faster. As long as it's good enough any performance difference is secondary.

Re: The world of pipe fittings

#243

Post by dsfyu404ed »

rsync wrote: post #121
kennend3 wrote: post #108

Earlier quoted context omitted.

As someone who is NOT a pipe fitter but lived with one for many years.. It was odd reading this and I'm glad someone like you responded to correct things. > 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. Again, not a pipe fitter but this just screams "WRONG". If someone needs to use that much force to tighten it up, one can only assume…

"My roommate had a "unlimited BTU" gas fitter license (Canada Class "A") and this for a living and preferred "pipe dope"" I do this kind of thing a lot as we own and maintain our own water plant. My preferred sealant is the yellow PTFE tape that is used for natural gas. It is quite a bit thicker than the white tape, it sticks to threads better and it is easier to work with, in terms of manual dexterity. I never use t…

>ALSO, helpful hint: If you are mixing plastic pipe (like schedule 40/80) and metal pipe, always have metal female couplings and plastic male couplings. A metal male going into a plastic female is one tighten away from cracking the plastic.

At some point it becomes easier to just think about what you're doing avoid being ham fisted moron than it is to seek out parts and design things to be accommodating to that kind of behavior.

Re: The world of pipe fittings

#244

Post by dsfyu404ed »

jimnotgym wrote: post #176
toast0 wrote: post #88

Earlier quoted context omitted.

They can't charge that much or people will do their own plumbing. It's fussy, but most routine things aren't too hard to do one step at a time. Sometimes you get a new faucet with an internal leak though, experience might have helped diagnose that without taking everything apart 20 times. Sometimes there's a big job like replacing a lateral, which is yeah, time to hire a pro.

In the UK gas work is regulated so only a registered plumber can do it.

You're not supposed to exceed the speed limit either...

Re: The world of pipe fittings

#245

Post by jve »

TEP_Kim_Il_Sung wrote: post #16
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…

hemp fiber > PTFE tape

Except hemp fiber is so long to work with to do a single joint (We'll I'm a DYIer, not a pro)...

What I find very useful is from a pro plumber: https://www.henkel-adhesives.com/us/en/product/thread-sealan...

Can be used for water & gas, withstands high temperature. Easy & fast to work with. Don't have to apply any additional grease for reducing friction.

Re: The world of pipe fittings

#246

Post by jve »

robk wrote: post #168
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…

This is more useful than Teflon tape I find https://www.amazon.co.uk/Loctite-K97870-Henkel-Sealing-Multi...

Thanks for mentioning this. This is so easy and fast to work with and you usually end up with sealed joints (Sorry, I'm an amateurish DIYer, first tries were failing). No additional grease needed to reduce friction, withstands high temps, for water and gas. What's not to love? Price maybe.

Re: The world of pipe fittings

#247

Post by btbuildem »

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…

Teflon tape is a lubricant, it's not meant to seal the joints. So for example if you're screwing a shower head "hockey stick" pipe into a drop ear elbow in the wall, and it stops at a weird angle instead of pointing down -- use PTFE tape on the threads to make them slide against the ones in the fitting more easily, it'll turn further.

To seal a NPT-threaded joint, use pipe dope (it's both a lubricant and a sealant).

Re: The world of pipe fittings

#248

Post by bhandziuk »

ssl232 wrote: post #183
thedanbob wrote: post #6

I had a major plumbing problem some time ago (leak in the house’s main line) and paid a plumber way too much to dig a hole and fix it. I of course wasn’t about to pay him to fill the hole back up, and while it was open I took a good look. That’s when I discovered PEX. PEX is wonderful: easy to work with, inexpensive, simple to fix if you screw something up. I wish all plumbing was PEX. I briefly installed an NPT flow…

I've not done any major replumbing yet but I've been watching Matt Risinger [1] on YouTube for a few months and have quickly become a PEX fanboi. He's a home builder based in Texas and uses PEX for basically every job. There are some videos on his channel comparing different types of PEX and PEX against other systems. [1] https://www.youtube.com/@buildshow

His channel is great but it gives a false sense of what can be accomplished on my budget most of the time. It's always far above what I can afford but If I can even replicate 10% of what he does I'll be better off than most.

Re: The world of pipe fittings

#249

Post by jkqwzsoo »

rsync wrote: post #121
kennend3 wrote: post #108

Earlier quoted context omitted.

As someone who is NOT a pipe fitter but lived with one for many years.. It was odd reading this and I'm glad someone like you responded to correct things. > 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. Again, not a pipe fitter but this just screams "WRONG". If someone needs to use that much force to tighten it up, one can only assume…

"My roommate had a "unlimited BTU" gas fitter license (Canada Class "A") and this for a living and preferred "pipe dope"" I do this kind of thing a lot as we own and maintain our own water plant. My preferred sealant is the yellow PTFE tape that is used for natural gas. It is quite a bit thicker than the white tape, it sticks to threads better and it is easier to work with, in terms of manual dexterity. I never use t…

The color isn’t necessarily related to the tape density. I always use Merco Threadmaster M66 (I think this, or the M77, is the McMaster default for high-density tape), which comes in all colors. I’ve had cheap tape come prepackaged with products that’s almost transparent and not with bothering with.

I also find it really helps to use the right tape width for the fitting you’re working with. I work mostly on small laboratory/pilot scale stuff (that needs to come apart in a few years, so no dope). I rarely use a fitting larger than 1/2”, but when I do, it’s a pain to use 1/2” tape. 1” (or 1.5”) will make a much neater and more consistent job. Similarly, I prefer 1/4” tape for 1/8” and smaller fittings.

Re: The world of pipe fittings

#250

Post by jkqwzsoo »

rsync wrote: post #233
couchand wrote: post #169

Earlier quoted context omitted.

I've seen people suggest that white tape should only be 1.5-2 but yellow should be 5 or more, do you have thoughts on that? Is there a difference in usage or is it the same overuse pattern on both?

I have no idea. I don't think you can use too much tape. Suggestions that you can break fittings with too much tape are almost certainly incorrect - with either plastic or metal. I usually do 5-ish wraps with the thick yellow tape - and that is true with schedule 40 PVC, plain old galvy, or with small stainless fittings. I am wasting tape, and I know it, and I have no problem with that - and neither do the fittings.

You can definitely break a plastic fitting with too much tape. The tape and the plastic are deformable, and I’ve had taped PVC fittings effectively extruded by repeated installation with fresh tape (every time you install it, you need a little bit more). This effect will be amplified if you’re fitting is made out of a material more prone to creep like PVDF, PP, or Nylon. Granted, this isn’t a typical (or appropriate) use case, but it was a necessary kludge for a project I had.

You can get leaks with too much tape if it prevents you from reasonably getting the threads to seal. When this happens, you get a slow leak between the layers of the tape. I’ve seen water slowly bead out of fittings at 1000 psi due to this.

Also, too much tape can lead to contamination (the tape sticks to every piece of dust, lint, and oil in your workspace) and can make it easy to cross thread fittings (especially small plastic ones).

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