1/2" Copper to 1/4" Plastic Tubing

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by kristof, Apr 21, 2009.

  1. kristof

    kristof New Member

    Messages:
    9
    I'm planning to install a "point of use" water filter system. It's the kind that's normally mounted under the kitchen sink. The filter unit accepts 1/4" LLDPE plastic tubing. It's similar to the stuff that's often used to supply refrigerator icemakers, but slightly superior. (If anyone can tell me exactly how it's superior, I'd really like to know.)

    These water filters are usually mounter under the kitchen sink. We don't have room under there so I plan to mount ours in the basement. It's still technically under the kitchen sink! :)

    The complication is that I can't use the normal procedure to tap into the water supply. Normally, a special tee (plastic!) is screwed onto the output of an angle stop. It provides a pass though for the displaced faucet supply line and also a 1/4" tubing connection for the filter.

    We have a Zero Tolerance Policy for water leaks in our house. We've dealt with two defective icemaker hookups over the years. (None were done by me!) We don't want another water incident. I've become very picky about having every bit of plumbing "done right" above all else.

    Here are the options I've come up with so far:

    Option #1 - The Lame Duck
    Use the same funky 3/8" angle stop adapter that everyone else uses on these filters. Install it under the sink and fish the supply tubing down to the basement and into the filter.

    This approach highly unappealing. I don't trust the adapters and I don't like idea of the supply being in a different room from the filter. If that plastic adapter breaks my kitchen is flooded.

    Option #2 - The Elegant Solution
    Tee off the 1/2" copper. Install a copper sweat ball value for shutoff. Install a sweat copper to 1/4" NPT Female adapter. Screw in a John Guest 1/4" NPT Male to 1/4" tubing "stem" fitting. Done.

    Here's the John Guest part:

    http://www.usplastic.com/catalog/va..._name=26485&product_id=26308&variant_id=58298

    Are 1/2" copper sweat to 1/4" NPT Female adapter available at the local big box? I've read about them but never seen one on the shelf.

    Option #3 - The Less Elegant Solution
    This one is exactly like #2 except that I would substitute a 1/2" copper to 3/8" NPT Female adapter followed by a similar John Guest fitting in 3/8". I would then use a John Guest reducer to get from 3/8" tubing to 1/4" tubing. Done.

    The only way this makes sense over #2 is if I can't find a 1/2" sweat copper to 1/4" NPT Female adapter in the local stores.

    Option #4 - The Angle Stop Solution
    Tee off the copper. Install an angle stop with 1/4" compression output. (I don't know if I can find that locally. I've seen them in the Watts catalog.) Attach tubing. Done

    Option #5 - The Icemaker Kit Solution /w Ball Valve
    Tee off the copper. Install a copper sweat ball value for shutoff. Sweat on a short capped stub. Pop a saddle valve with 1/4" compression output onto the stub. Attach tubing. Done.

    Option #6 - The Icemaker Kit Solution
    Randomly vampire a saddle valve onto the closest piece of cold supply line. Attach tubing. Done.

    Which is the most professional and leak free over the long haul?

    Are there any other good ways to do it?

    I have one ancillary question regarding connection of tubing to compression fittings. No matter which supply strategy I choose I'll still have at least two transitions from 1/4" tubing to 1/4" compression on the delivery side: one at the faucet and the other at the icemaker.

    A few companies make adapters that screw onto 1/4" compression fittings and provide a 1/4" tubing push-to-connect on the other side. They call them "faucet connections" or "7/16-24 UNS Female to 1/4" tube fittings".

    Here's one example:

    http://www.rosystems.com/reverse-osmosis/water-treatment-products/U-0420705.html

    Should I use those for all of my compression to tubing junctions or should I go with standard compression joints (nut + plastic ferrule)?

    Both of our previous water damage incidents were due to leaks in poly tube compression fittings. Our refrigerator's water input even has a warning against connecting plastic tubing to its brass compression inlet.

    The John Guest compression adapters are expensive and very difficult to source. is it worthwhile to use them rather than standard compression joints?

    (The one I linked to above is made of acetal. I need to find the same fitting in polypropylene.)

    Thanks much if you've read this far. I really need the advice. I've been spinning my wheels on this project for too long.
  2. mattbee24

    mattbee24 In the Trades

    Messages:
    100
    Location:
    Fremont, OH
    Option #2 is how I always do it. I hate compression fittings on plastic line. One other thing I do when using the plastic line is to put a short stub of copper tubing off of the fridge, then use a John Guest coupling to connect the copper tubing to the plastic. I don't know if this is the best way, but I feel a lot more comfortable with it.
  3. kristof

    kristof New Member

    Messages:
    9
    Great suggestion! That's a clever way to skirt the "no plastic to fridge" problem. It gives me another option for my other compression-to-plastic transitions too.
  4. Redwood

    Redwood Master Plumber

    Messages:
    7,452
    Location:
    Connecticut
    How about installing a Brasscraft 1/2" sweat (5/8" Nom.) X 1/4" Comp. stop valve similar to the one in this brochure linked below, and then using a 1/4" braided stainless ice maker supply line to the RO Filter? What are you using for a drain connection for the RO Filter?

    http://www.brasscraft.com/PDF/Brass Craft - The New Twist in Quarter-Turn Brochure.pdf

    I would have gotten the P/N for you but the web link for it is not working right now...
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,513
    Location:
    Cave Creek, Arizona
    water

    He said it was a filter, not an R/O unit. I use option #4. Do not even consider options 5 and 6.You need a hole new valve.access as it mus be Place the brass support insert sleeve into the plastic tubing before you tighten the compression nut and you will have no problems.
  6. kristof

    kristof New Member

    Messages:
    9
    Correct. This is not a Reverse Osmosis unit. This is only a filter. There is no RO membrane. No drain line is needed.

    Option #4 seems like a good one but I haven't found a 1/4" output angle stop locally.

    I like options #2 and #3 best but I'm not having much luck finding sweat to 1/4" or 3/8" NPT. I can't even find one with google.

    I suppose I could do 1/2 sweat to 1/2 NPT and then 1/2" NPT to 1/4" NPT reducer. I haven't looked for either of those fittings locally yet.

    Anyone know a good plumbing shop in Pittsburgh, PA? Preferably, one whose employees don't tell you to "come over to see" when you call asking about specific fittings.

    I wasn't around to diagnose the plastic line compression failures we've had. For all I know they could have forgotten the stiffener insert or used a metal olive instead of plastic.
  7. kristof

    kristof New Member

    Messages:
    9
    Haven't found 1/2" sweat to 1/4" compression angle stops locally yet. Everything seems to be push-on or compression on the input side. It seems like "they" don't want DIY's sweating angle stops anymore.

    I have found 1/2" compression to 1/4" compression but I have zero experience with 1/2" copper compression. Those are for 1/2" copper pipe correct? Not flexible copper tubing. I guess that's what the "nom." designation is for.

    I'd really like to stick with the LLDPE tubing. I have to deal with it on the output side anyway. Using standard braided lines on that output side is a no-no because they put back a bunch of the nasty chemicals that the filters are there to remove. I installed a new braided line to our icemaker over a month ago and our icecubes still taste like plastic. It's a good quality Watts line too.

    Also, the filter housings aren't set up for braided supply line. I'd have to do some fitting gymnastics to make that work.

    No RO, just a filter, so no drain needed.

    I have the Brasscraft Supply PDF on my computer. I'm guessing you were talkiing about KTR09.
  8. Redwood

    Redwood Master Plumber

    Messages:
    7,452
    Location:
    Connecticut
    Some of that plastic taste may actually be frome the refridgerator itself. If you are sure it is the supply I would change it out to another brand.

    I'm not sure without looking but if you find the part number for a 1/4 turn straight or angle stop that is 1/2" sweat(5/8" Nom.) X 3/8" compression and call supply houses with the p/n they should tell you if it is in stock or they can get it, with out saying come on down...

    Sorry about the RO bit... I musta mixed posts up in my head...
  9. kristof

    kristof New Member

    Messages:
    9
    It's definitely the supply line. The refrigerator is old. It made fine ice before the supply line was changed. I was very disappointed upon install. We ran the icemaker constantly for two weeks before the cubes were usable. We dumped out ice by the bushel.

    Even now I can still detect the odor in certain beverages at certain temperatures. Diet soda is one of them. It's there plain as day.

    I'm going to look into at mattbee24's suggestion. I'm dying to ditch that supply tube!

    No problem! :) I'm always happy when anyone takes the time to help me, no matter what.

    It looks like I'll be going with a variation on Option #3. I don't need the John Guest reducer at the end. They have a fitting that they call "STRAIGHT ADAPTOR" that's 3/8" MNPT to 1/4" tubing.

    This will be my final supply setup:

    • Tee off copper
    • Sweat ball valve
    • 1/2" sweat to 3/8" FNPT (Elkhart Products C6031238)
    • 3/8"MNPT to 1/4" OD tubing (John Guest Straight Adapter PP010823W)

    This is an inexpensive solution and all of the copper is readily available at the local big box. The John Guest fitting is cheap (versus the John Guest faucet connection fitting I mentioned earlier in the thread) and it's widely available on the internet in polypropylene. Many stores only carry acetal fittings or only offer select items in polypropylene.
  10. kristof

    kristof New Member

    Messages:
    9
    Have you ever had any leaks with this approach? I'm leaning towards using it on my icemaker.
  11. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,917
    Location:
    New England
    Not sure why you can't use copper tubing all the way into the icemaker. On mine, I have about a 10' length single large loop behind the frig (probably about 4-5' in diameter) so you can pull it out without kinks.
  12. mattbee24

    mattbee24 In the Trades

    Messages:
    100
    Location:
    Fremont, OH
    It's not that you can't use copper tubing the way you suggest. I am just always paranoid it will kink.

    P.S. Take all my advice as just an opinion. I'm not a professional.
  13. Redwood

    Redwood Master Plumber

    Messages:
    7,452
    Location:
    Connecticut
    My experience exactly...
  14. kristof

    kristof New Member

    Messages:
    9
    If it was just a standard icemaker hookup all-copper would be fine. Plumbing the whole output side of my filter system with copper tube would be expensive and a pain. The filtered water is going multiple places.

    Also, copper is inappropriate for Reverse Osmosis water because RO water can be highly corrosive.

    My filter system is not RO but it could be converted to RO with the addition of few parts. I wouldn't want to re-plumb if I decided to go RO in the future.
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