Author Topic: Tightening nipples and pipes  (Read 1189 times)

Offline natbr

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Tightening nipples and pipes
« on: May 14, 2018, 06:44:37 AM »
OK .. with a title like that, I need to get right to the issue:

Does anyone have a good strategy for tightening or loosening steam nipples or pipes on model steam plants?  I don't and therefore am either trashing the threads on nipples or using a small channel-lock on pipping -- but the result is the same -- I'm creating scratches, divots that I then have to sand/buff out or tool out with threads.  There must be a better way... is there?

Thanks!

Nat


Offline Jasonb

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Re: Tightening nipples and pipes
« Reply #1 on: May 14, 2018, 07:22:44 AM »
Are you soldering the nipple to the pipe? They do not need to be compressed onto the pipe like an olive in a domestic compression fitting.

Once soldered you should not need much force to tighten the nut as the tapered end forms the seal

Online Jo

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Re: Tightening nipples and pipes
« Reply #2 on: May 14, 2018, 07:59:11 AM »
I think you need to explain more about what you are trying to do Nat.

It sounds like you might be trying to use a huge (adjustable) spanner to tighten up a little fixing... The correct size full hex spanner should not damage the nuts or allow you to strip threads.

Jo
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Offline Bluechip

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Re: Tightening nipples and pipes
« Reply #3 on: May 14, 2018, 08:09:40 AM »
Too true .... had to search 'channel-lock'. I suspected from waaaaay back they had serrated jaws. ie.

What 'we' know as 'slip-joint' or 'pump gland pliers'   :ThumbsUp:

www.bing.com/images/search?q=channel+lock&FORM=HDRSC2

I expect they would chew hexagons and tube.  :'(

Dave


Offline natbr

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Re: Tightening nipples and pipes
« Reply #4 on: May 15, 2018, 04:19:41 AM »
Ok. Uploaded some pictures: on the steel nipples picture -- the steel nipples screw into the fittings -- and with a little locktite are pretty set. However, if they leak or I want to use them elsewhere -- any idea of how to get them out without trashing the threads?  Same thing with the brass pipes -- when they leak, I need to tighten them up... Any good strategies on tightening pipes without using tools with serrated jaws?  As you can see in the refill pipe jpg, I sacrificed that to get it good and tight into my boiler.  Also, on the coupling ... its pretty trashed too where I was tightening it up.

-- Nat

Online Jo

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Re: Tightening nipples and pipes
« Reply #5 on: May 15, 2018, 05:14:57 AM »
Have you considered adding a lock nut on the threaded part? That way you can hand screw in the pipe and use the lock nut to tighten the thread.

On the elbows the use of a smooth well fitting spanner should prevent damage but the only way you will get things pointing the right way without forcing/stripping threads is to lock the fitting in place with a lock nut  :).

It might also be worth considering that Plumbers use PTFE tape or jointing compound to help seal joints  ;)

Jo
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Offline Jasonb

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Re: Tightening nipples and pipes
« Reply #6 on: May 15, 2018, 07:19:01 AM »
What number loctite are you using? they do specific thread sealing ones which are far easier to unscrew than thread locking ones. Liquid PTFE also works well on the small threads rather than tape.

Use of a hand held drill chuck or ER collet on pipe will prevent the surface from marking or the pipe crushing.

Using only parallel pipe threads also makes things easier.

Offline Bluechip

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Re: Tightening nipples and pipes
« Reply #7 on: May 15, 2018, 08:39:31 AM »
Some nipples are/were obtainable with a screwdriver slot across the end.

This was from ages ago when i had some dealings with pneumatic automation.

It was in UK but I suspect you're not.?

IIRC 1/8" & 1/4" BSP  :headscratch: :old:

If you have the facility nothing to stop you putting a slot across one [ usually ] end of a nipple.

Dave
« Last Edit: May 15, 2018, 08:43:53 AM by Bluechip »

Offline Stuart

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Re: Tightening nipples and pipes
« Reply #8 on: May 15, 2018, 09:17:57 AM »
J & J

NO ptfe on boiler fitting please any loose strands or ptfe bit will block injectors and affect safety valves
Donít ask how I know
My aim is for a accurate part with a good finish

Offline Zephyrin

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Re: Tightening nipples and pipes
« Reply #9 on: May 15, 2018, 09:54:41 AM »
You may use nuts, shop made thin nuts, to lock the nipple on the tee or other junctions...
the dismantling becomes easier if you don't lock the nipple in the elbow but lock it with the nut, no crushed thread !
On my gauge one locos, most of the time this assembly is pressure tight in its own, nothing to add but a drop of grease.


Offline natbr

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Re: Tightening nipples and pipes
« Reply #10 on: May 16, 2018, 07:42:41 AM »
Thanks for the recommendations!  I think thin lock nuts are the way to go.  I have lots of hex stock with a copper washer, should work great.  I did a test at slotting in brass pipe -- and seemed to work ok. So I'll use that as backup.

Loctite products:  542 as thread sealant for steam pipes, etc.  For none pressurized stuff, using Locktite 243 as a thread locker.  Any issues there?

I will say the Locktite 542 is really tough stuff ... the only real way to clean old residue off a bolt is by heating it up with a torch and scrubbing with a wire brush.  I only apply when I think I have everything *exactly* the way I want them.

thanks again!

-- Nat