Help in Identifying Kitchen Sink Connection

[Yoda]

Cate&Rob howson TucsonJim Hoping you guys might know the answer.


Can anyone please identify theses Pex connections. I know its 1/2" but by what???? Is it cone, NTP, etc. I tried a quick search. Before I brake something I want to get the correct brass fittings I need ro reroute the plumbing lines to make my insulation fit at the water tank and do my gray tank support. It is nice the sink connections are marked hot and cold - gives me a 50/50 chance of hooking it back up correctly

Thanks
Keith

[gtippett]

Yoda they are NPT and have a cone shaped rubber "gasket" inside. They are similar to the others in the Rig, like the low point drains (but not sure if they are the same size). By the way Lippert states these are 5/8 inch, which isn't true. Learned that as I recently installed a under sink filter system.

[Country Campers]

!/2" pex - 1/2" NPSM

Here is a link to a example UC526LF - SharkBite UC526LF - 1/2" PEX Crimp x 1/2" NPSM Brass Swivel Adapter (Lead Free) (supplyhouse.com)

Also available in 90 degree. Get some of each to have on hand when needed, also a few cone washers.

Brian

[Yoda]

I got theses at Home Depot Was told it was the same as what I had.

I can take back tomorrow if needed. I just check one on the sink connection and it seems to fit....maybe I got lucky

Thanks for the help
Keith

[Cate&Rob]

Hi Keith,

You are likely combining NPT (National Pipe Tapered) thread and NPS (National Pipe Straight) thread parts. Tapered threads seal on the threads (often with pipe dope or teflon tape) whereas straight thread fittings seal on an internal soft cone washer. But . . . if the NPT male fitting has a smooth end, the NPS female fitting (with the cone washer) will usually seal because the thread pitch is the same.

Have I totally confused you . . . LOL!

Rob

[TedS]

The female swivel will fit the male NPT thread. The cone washer will conform to the face and ID edge of the male thread. Generally the NPS straight thread is used for structural connections like pipe railing.

[Yoda]

Hi Keith,

You are likely combining NPT (National Pipe Tapered) thread and NPS (National Pipe Straight) thread parts. Tapered threads seal on the threads (often with pipe dope or teflon tape) whereas straight thread fittings seal on an internal soft cone washer. But . . . if the NPT male fitting has a smooth end, the NPS female fitting (with the cone washer) will usually seal because the thread pitch is the same.

Have I totally confused you . . . LOL!

Rob

So this is what I really need https://www.homedepot.com/p/SharkBit...FA10/318224400 or will what I have work - yep you discombobulated my mind too..

Keith

[Yoda]

TedS Cate&Rob
This is the male ends of the kitchen sink feed lines They appear to be smooth end and slightly beveled.


This are the fittings I got from HD https://www.homedepot.com/p/Apollo-1...212S/301541047
Do I need to get something else?

Thanks - hopefully I am becoming confused less than I was

Keith

[Country Campers]

Keith,

I think that either one of the ones you have or linked to will work just fine. When using the NPT version the nut may tighten up before the cone washer seals the way it should but usually is not a problem. Straight threads are better in most if not all cases in the RV.

Also please do not use large words like "discombobulated", this is a family channel and some here may take offense to words with more than 4 or 5 letters used (LOL)

Brian

[TedS]

I'm going to guess Apollo misnamed or alternatively named the thread in the swivel as FNPT yet include cone washer and not intend to seal on the thread form. Could be they mean Female National Pipe Thread.

On edit: going out on a limb. All female pipe swivels will be straight pipe thread, not tapered. Tapered thread would seal on the threads and leave the swivel joint to leak. The swivel needs some interior means of sealing, either cone seal or cone seat.

[Yoda]

Keith,

I think that either one of the ones you have or linked to will work just fine. When using the NPT version the nut may tighten up before the cone washer seals the way it should but usually is not a problem. Straight threads are better in most if not all cases in the RV.

Also please do not use large words like "discombobulated", this is a family channel and some here may take offense to words with more than 4 or 5 letters used (LOL)

Brian

LOL So Brian I am limited to four letter words....i remember getting my mouth washed out with soap for that LOL

Does that mean I cant use supercalaificaigilicexpealidoucius? (SP) I looked it up "supercalifragilisticexpialidocious". I used to be practically perfect in every way and could spell that! Got an A on a spelling test for that rather than the usual C- .....yep back to my corner

So Ted TedS your saying I should be good too. Your thought makes sense as you don't want the female swivel binding up on the threads. Should I use Teflon tape BTW? I guess I had better leave some slack in the line somewhere, just in case

Thanks for the education folks - good thoughts.

Do - don't try ....that is tomorrows thought

Keith

And all this to move two lines from over a gary tank to around it (maybe 1' to 2') and 2" to clear the fresh water tank.But being the engineer I am I did not want to splice the lines -DOH!

On edit - Now for the laugh - I offered SWMBO the chance to change out the low low low flow kitchen faucet - she declined

[Country Campers]

Keith,

There should be no need to use teflon tape on these fittings, it will not help seal at all.

Brian

[TedS]

Brian is correct. Do not tape the threads. Would have no effect.