# Dishwasher connection **URL:** \ **Category:** Factual Questions\ **Created:** [January 19, 2014, 9:39pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226 "2014-01-19T21:39:11Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Simmerdown](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/simmerdown/32/14859_2.png) [@Simmerdown](https://boards.straightdope.com/u/Simmerdown)\ **Post date:** [January 19, 2014, 9:39pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/1 "2014-01-19T21:39:11Z")
Can anyone tell me if there is a reason I shouldn’t use [this](https://picasaweb.google.com/CoolMotet/January192014#5970714583755936978) (1/2" to 3/8", I believe–chrome, not brass?) to attach [this](https://picasaweb.google.com/CoolMotet/January192014#5970714588009657954) to [this](https://picasaweb.google.com/CoolMotet/January192014#5970714588132217954)? The installer said I needed some other kind of connector, one with a “white plastic thing” inside (though I can’t think of a reason for it), but the way he described it I thought it would be easy to find at the hardware store. The lackey at the store was no help, I’m assuming, because it seems entirely possible that the connector I have (the first “this”) is just fine, and to him my installer’s instruction was just daft (I’m hoping this is the case). But since the vast bins bulge with many different gizmos with which I am unfamiliar, seeing as a great deal of my ignorance encompasses matters of plumbing, I thought I’d turn to you all before I just give up and just put it on anyway. Don’t really want to pay a plumber $120 to do what I can do myself. BTW, I did buy one of those hook-up kits, but I haven’t opened it yet. By the description of the contents and what I can see inside the partially transparent package, there isn’t anything in there that sticks out as being “whoa, that’s what I need!” Plus, if I don’t need all that crap, I’d just as soon take the kit back. As an aside, I am a little suspicious of installers. They often seem to claim they can’t complete an installation for some reason or another. A similar thing happened with the new fridge (as yet uninstalled), on the same day, with different installers, but that will be a subject for a different thread. Thanks for any help, and I’ll supply extra info as needed. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [January 19, 2014, 9:47pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/2 "2014-01-19T21:47:55Z")
None of your links are working for me. ---
**Author:** ![Simmerdown](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/simmerdown/32/14859_2.png) [@Simmerdown](https://boards.straightdope.com/u/Simmerdown)\ **Post date:** [January 19, 2014, 9:48pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/3 "2014-01-19T21:48:44Z")
Whoops. Will try to fix. ---
**Author:** ![Simmerdown](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/simmerdown/32/14859_2.png) [@Simmerdown](https://boards.straightdope.com/u/Simmerdown)\ **Post date:** [January 19, 2014, 9:57pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/4 "2014-01-19T21:57:06Z")
I think this fixes it: [This 1](https://picasaweb.google.com/CoolMotet/January192014?authkey=Gv1sRgCJ_l45r04ZTqeA#5970714583755936978) [This 2](https://picasaweb.google.com/CoolMotet/January192014?authkey=Gv1sRgCJ_l45r04ZTqeA#5970714588009657954) [This 3](https://picasaweb.google.com/CoolMotet/January192014?authkey=Gv1sRgCJ_l45r04ZTqeA#5970714588132217954) ---
**Author:** ![Simmerdown](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/simmerdown/32/14859_2.png) [@Simmerdown](https://boards.straightdope.com/u/Simmerdown)\ **Post date:** [January 19, 2014, 10:21pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/5 "2014-01-19T22:21:26Z")
If you’re viewing in Tapatalk, or somesuch, and clicking on the link shows three different images side-by-side, the item in question is the adaptor (on top of the legal pad), third in the bunch. Sorry for any awkwardness in the links. I Don’t use Picasa very often. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [January 19, 2014, 10:41pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/6 "2014-01-19T22:41:16Z")
Looks like you have a female 1/2 NPT (national pipe thread)to 3/8 male Ferrell adaptor. Your wall shut off valve looks to be 1/2 Ferrell. It will leak. ---
**Author:** ![Simmerdown](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/simmerdown/32/14859_2.png) [@Simmerdown](https://boards.straightdope.com/u/Simmerdown)\ **Post date:** [January 19, 2014, 11:33pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/7 "2014-01-19T23:33:11Z")
> [@Snnipe\_70E](#): > > Looks like you have a female 1/2 NPT (national pipe thread)to 3/8 male Ferrell adaptor. Your wall shut off valve looks to be 1/2 Ferrell. It will leak. Well, that’s a start. In an attempt to be less needy, I Googled both NPT and Ferrell in various iterations and came up with very little (read “nothing”) that makes the solution to my problem more obvious. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [January 20, 2014, 12:55am UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/8 "2014-01-20T00:55:19Z")
Ferrule, not ferrell. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [January 20, 2014, 1:42am UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/9 "2014-01-20T01:42:09Z")
> [@friedo](#): > > Ferrule, not ferrell. Thanks friedo. Pipe threads are tapered. As you tighten the fittings the taper squeezes the fittings together sealing the threads. The ferrule nut has no taper so the threads will be loose. More later. ---
**Author:** ![Simmerdown](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/simmerdown/32/14859_2.png) [@Simmerdown](https://boards.straightdope.com/u/Simmerdown)\ **Post date:** [January 21, 2014, 3:58am UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/10 "2014-01-21T03:58:48Z")
When you say “tapered” are you talking about [this bit](https://www.google.com/search?q=tapered+thread&tbm=isch&source=iu&imgil=d-Z5a7XjWIfi6M%253A%253Bhttps%253A%252F%252Fencrypted-tbn1.gstatic.com%252Fimages%253Fq%253Dtbn%253AANd9GcTJIrE54ZOVjhkVTR1Z01kYdilfpo2O-6r73E5dpkryS97pVMhZ%253B300%253B174%253BKDjpSezwy3bn9M%253Bhttp%25253A%25252F%25252Fwww.ien.com%25252Farticle%25252F4-easy-steps%25252F164884&sa=X&ei=K-_dUuvpJYaIygG99IGYAw&ved=0CDAQ9QEwAQ&biw=1528&bih=915#facrc=_&imgdii=_&imgrc=d-Z5a7XjWIfi6M%253A%3BKDjpSezwy3bn9M%3Bhttp%253A%252F%252Fwww.ien.com%252FuploadedImages%252Fien%252FArticles%252FHow_To%252FTaperedThreadParallelThread_L.jpg%3Bhttp%253A%252F%252Fwww.ien.com%252Farticle%252F4-easy-steps%252F164884%3B300%3B174) on the left? Wider at the bottom, narrower at the top? (This illustration being male rather than female). But my shutoff doesn’t look tapered. What gives? Please elaborate. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [January 21, 2014, 6:19am UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/11 "2014-01-21T06:19:14Z")
> [@Simmerdown](#): > > When you say “tapered” are you talking about [URL="[Google](https://www.google.com/search)? on the left? Wider at the bottom, narrower at the top? (This illustration being male rather than female). But my shutoff doesn’t look tapered. What gives? Please elaborate. Your shut off valve is not NPT but is ferrule, therefore straight threads. Your adaptor’s female end is NPT and tapered. this is a miss match. One solution, A short section of 1/2" tubing with ferrule fittings on both ends. 1 adaptor 1/2" male ferrule by 1/2" male NPT. Screw the two adaptors together, connect the tubing. Second solution You may be able to find a connecting hose with a 1/2" ferrule fitting on one end and a 3/8" on the other end. Then get a 3/8"X 3/8" connector. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [January 21, 2014, 6:36am UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/12 "2014-01-21T06:36:07Z")
Your pics 2 and 3 are of items used for the supply side - the valve goes on the supply pipe, the hose (presumably) is to connected the (hot) water supply (the valve) to the dishwasher inlet. The person was trying to say “air gap” for the outlet - a small hose goes in, a larger goes out. It mounts on the deck of the sink and provides an air vent for the drain. It has a (usually chrome finish) cap about 2" in diameter and 3" tall. The smaller hose comes from the dishwasher, the larger outlet goes into the garbage disposal (if present) or a special tailpipe in the drain line. Yes, it has white plastic inside. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [January 21, 2014, 6:56am UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/13 "2014-01-21T06:56:07Z")
if you’re installing a used unit then it probably has the old right angle adapter to the water inlet side of the unit installed. Seen in this [video](http://www.youtube.com/watch?v=CHi7NfGsBj0) at 4:50. The reason I mention this is that you may need to change that out depending on your current water connection method. I once spent the better part of a day trying to hook up one type of line using adapters to the elbow when I just needed to swap out the elbow. ---
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [January 21, 2014, 5:52pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/14 "2014-01-21T17:52:02Z")
I believe this calls for a Langstrum gangley wrench. ---
**Author:** ![randompattern](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@randompattern](https://boards.straightdope.com/u/randompattern)\ **Post date:** [January 21, 2014, 6:05pm UTC](https://boards.straightdope.com/t/dishwasher-connection/679226/15 "2014-01-21T18:05:45Z")
You could use a compression union between the hose and the valve. Remove the cap nuts and ferrules from the compression union and it will adapt the two pieces.