Threaded male adapters onto new shower diverter..?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by lithnights, Mar 22, 2006.

  1. lithnights

    lithnights New Member

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    Next step in my bath remodel... ready to install the new shower diverter.

    The diverter ends are female, so I have male adapters that I am going to screw in and then solder copper to the other end of the male adapters. Then solder 90s to the incoming supply pipes. See picture of the dry fit.

    1) But do I use dope or sealant or what here? I have read a bunch of threads here about dope/no dope but none discuss specifically what to do when dealing with a diverter. Most discuss compression valves. Perhaps it doesn't matter, but I just wanted to check since once I solder on the male adapter, I'm not sure how I would ever turn/tighten that male adapter. See next question..

    2) What if, for some reason, there is a leak where the male adapter goes into the diverter? There's no real way to tighten it since it's soldered to the copper pipe? Is there? If you tightened it, you'd move the whole copper pipe..

    3) The diverter instructions state to put it 30" above the tub bottom and the spout at 22". My old diverter was at 24" and 18". Can't I just install my new diverter at the old heights?? I cut everything according to the old diverter location..

    Thanks,

    Attached Files:

    Last edited: Mar 22, 2006
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    THere are basically two types of threaded connections used in plumbing - threads similar to what is on the end of a hose (straight threads similar to those on a machine screw - when you thread on a nut, it will keep going without interference or resistance from one end to the other), and an interference (tapered) thread (this connection gets tighter the further you screw in the male portion).

    When you use a normal, straight thread, you need a washer or gasket of some type to actually make the seal (like on your hose). A tapered thread needs something to seal the threads - pipe dope or teflon tape (or both). The taper just makes the mechanical connection, not a waterproof seal.

    So, for what you are doing, you need dope and or teflon tape.
  3. Bob NH

    Bob NH In the Trades

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    You should be OK with the heights as long as the height above the top of the tub meets the code air gap requirements.

    This amatuer will often solder to the male adapter with a length of pipe, and even put on the elbow that you show, with a piece of pipe if approximate length can be determined, and screw them into the valve, before mounting the valve. Then I don't have to worry about messing up either the valve or the thread sealant with heat.
  4. lithnights

    lithnights New Member

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    That's good to know. I will go with the dope. I also assumed that if I applied teflon tape and then soldered the other end of the adapter, that the solder would somehow melt/ruin the teflon tape on the male end of the adapter. Would it?

    Also, can you tell by sight whether a thread is tapered or not? I am going to assume all male adapters I use are tapered but how would one know if something else is tapered or not?

    Thanks jadnashua
    Last edited: Mar 22, 2006
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    It's possible to mess up the teflon, but it takes a fair amount to do it. If the threaded connection doesn't simply screw in like a nut on a bolt, it is almost certainly a pipe thread. Normally, you can't screw it together more than about 3 turns by hand before it gets tight. If it bottoms out, then it's almost certainly NOT a pipe thread. Plus, if you look carefully, you can see it is tapered. If you look at some threaded black pipe in the store, you'll see that the threads taper out to nothing along the pipe; not the same way as a threaded bolt.
  6. lithnights

    lithnights New Member

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    Good idea. I had thought of doing that.

    But I guess I'm still not sure what someone would do if they screwed on the adapter and then soldered everything, and the discovered there was some kind of leak. I don't see how you could tighten up the threaded adapter without moving the whole contraption out of place.
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Do it right the first time, or tear it apart and try again...
  8. hj

    hj Moderator & Master Plumber Staff Member

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    leak

    If you have a leak, you get out the hacksaw and cut it apart and start over. but if you screw the adapter into the valve and then solder the tubing into it you will probably have a leak, because the heated adapter will expand the valve body, but it won't "shrink" back to its original size when it cools. The adapter will, but the valve body probably will not because it was stretched by the adapter, not just expanded from the heat.
  9. Cass

    Cass Plumber

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    Personaly I never solder male adap. when screwed into a valve. I solder the nipple on the adap. Screw the adap. in the valve then solder the 90 or
    what ever on other the end of the nip.. Male adap. take more heat to solder due to the added copper drawing the heat away. I also don't take chances with the valve even though I remove all parts first. Just my way.
    Last edited: Mar 23, 2006
  10. lithnights

    lithnights New Member

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    That makes perfect sense. I will give it a shot.
  11. lithnights

    lithnights New Member

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    Uh oh, I think I'm confused on this now. When I screw a male adapter into the diverter female threads, I can turn and turn and turn and turn with equal resistance until it fully tightens.

    Based on your description, that does NOT sound like a pipe thread. Thus, would dope still be needed here, or something else?

    Thanks,
  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    If it bottoms out without previously geting tighter, then is should have come with a fitting, typically with a washer of some sort on it. If that is the case, you normally wouldn't use pipe dope or teflon tape on it. In fact, it is unlikely to seal properly at all without the washer. One possibility is if you used a 1/2" adapter and it is a 5/8" thread....it would be loose and not tighten up.

    Double-check the instructions or check their website for a parts blowup/instructions. Any spare parts in the box?

    then again, I could be all wet.
  13. lithnights

    lithnights New Member

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    What I'm talking about is a standard copper piece with a male adapter on one end and an area to sweat 1/2" copper into on the other end. Typical piece that I get for $1 at HD. No washers at all. This screws into the shower diverter. I don't think the shower kit came with any such parts but I'll check later today.

    I should have attached a pic. they speak a thousand words.
  14. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

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    It should be tight well before bottoming

    I've had some fittings bottom before being tight, but they've all been foreign-made steel pipe adapters (e.g., 1/2" to 1/4" reducing bushing). And, they never sealed, even with copious Teflon tape and gobs of dope. Only solution was to find a higher-quality, 'Murrican-made fitting. Never had this problem with copper-to-copper or bronze, since they've all been decent-quality stuff. If you take the diverter and the fittings to a reputable plumbing supplier they might be able to offer some first-hand advice along with the higher-quality goods. Or call the diverter's 800-number for support (Moen is especially good, IMHO) and see what they have to say.
  15. lithnights

    lithnights New Member

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    I called the manufacturer. They suggested just using male adapters and lining them with teflon tape (no dope) before screwing the threads into the diverter.

    They said to just use standard male adapters so I am going to use the ones I got from HD. See picture.

    I guess we'll see what happens. I have an access panel for this shower so no worries right? ;)

    Attached Files:

  16. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

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    No worries?

    To test the worry factor, you could install everything in the first place through the access panel...
  17. lithnights

    lithnights New Member

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    Location:
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    I soldered most of the main joints and then used teflon tape to screw in the male adapters. Turned on the water and no leaks. And I always have the access panel if I need to do future work.

    I guess it's safe to say that if a sweat is leak proof when first done that it should stay leak proof for years to come?
  18. toolaholic

    toolaholic General Contractor Carpenter

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    my answer to heat on valve and sealent

    I use copper unions.solder unassembled than put it togeather. Never had an inspector bust me . no leaks either! some may say" unions shouldn't be buried,dummy :confused: " Never had a call back :)

    don't have a phone :p
  19. hj

    hj Moderator & Master Plumber Staff Member

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    unions

    I don't say, "Unions shouldn't be buried, dummy.", I say, "If you know how to do it properly, you don't have to waste money on unions."
  20. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

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    Hold diverter, turn world?

    I guess "most" answers the question of how you screwed in the adapters with the joints soldered? I use both Teflon tape and a wicked blue goo that gets all over everything. Just finished re-plumbing overhead after finding under-slab leaks, pressure-tested everything at 100psi and no pressure drop. (Actually saw a slight rise in the afternoon, which I blamed on the attic getting hot.) Seems to be holding water at 60 psi OK. Wife loves having hot water at the sink again. Life is good.

    Only problem I've had with the adapters you illustrated is their QC is terrible as far as the size of the hexes goes. Won't matter if you use an adjustable wrench on them, but in one situation I had to use a deep socket and had a lot of trouble. Wound up taking a socket to HD and matching up 9 adapters to the socket. You'd have the same problem with a fixed open-end wrench.
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