View Full Version : Which stop valve do I use?
Briandl
08-10-2008, 12:18 AM
This question is in regards to stop valves for a bathroom sink.
I'm used to seeing either one of the following:
Copper supply, use compression fitting
Galvanized Steel, use threaded fitting
The current configuration is a copper supply with a threaded brass (can't be copper right?) end soldered on.
So what exactly do I do with this, buy a threaded brass stop valve?
Thanks in advance!
Marlin336
08-10-2008, 01:51 AM
Use a 3/8" or 1/2" IPS by 3/8 compression valve. Brass and copper pipe threads are the same size as iron pipe threads.
Briandl
08-10-2008, 02:37 AM
I didn't think I could use a compression valve.
Here is what they look like for the record, although this isn't the one in question, it's the same:
http://img187.imageshack.us/img187/8932/1004654mw6.jpg
It appears that you have a 1/2" copper male adapter...you will use a 1/2" IPS X 3/8" compression angel stop and I would suggest a 1/4 turn stop. Use Teflon tape on the threads.
Briandl
08-10-2008, 10:56 AM
Does it have to be 1/2" IPS X 3/8" compression
Or can it be 1/2" IPS X 3/8" something else ?
Redwood
08-10-2008, 11:44 AM
3/8" compression is probably the most commonly used size outlet for faucets, dishwashers, and toilets. 1/4" compression would be used for icemakers, point of use water filters, and hot water dispensers.
What do you have in mind?
nhmaster
08-10-2008, 12:58 PM
Don't forget to get left and right handed valves:D
Redwood
08-10-2008, 01:24 PM
And call NH Master to borrow his left handed pipe wrench too!
nhmaster
08-10-2008, 02:21 PM
sorry I'm busy right now sorting out a box of left and right 16D galvanized spikes.
Briandl
08-10-2008, 02:31 PM
Can you use a stop valve with a compression outlet by just screwing braided stainless supply line into it OR say using a copper or chrome plate supply line that's put on via a compression fitting, or is a compression stop valve only meant to be use one way?
Redwood
08-10-2008, 02:36 PM
Use this type of connector it will thread right onto the valve. The one shown below is for toilets.
Note: Do Not Buy the the Watts Floodsafe Connectors that big orange box pushes.
http://www.watts.com/prod_images/hi-res/3812TSS.jpg
Ian Gills
08-10-2008, 02:42 PM
If any of you would like me to go to the storeroom and ask the bloke there for a left-handed anything, then please let me know.
Briandl
08-10-2008, 02:51 PM
Thanks, sorry for being such a noob, I've actually done this a few times before, but I saw what I was expecting to see, this time I didn't.
What's this left hand joke?
:)
Redwood
08-10-2008, 03:05 PM
Phew, glad you recognized the joke!
Briandl
08-10-2008, 03:11 PM
I didn't, but since you helped I don't mind you guys having fun at my expense...
nhmaster
08-10-2008, 03:11 PM
It's something we like to do to apprentices. Send them to the truck for a left hand pipe wrench, then wait to see how long they are gone. It carries over to all the trades.
rpaquet
08-11-2008, 04:43 PM
It appears that you have a 1/2" copper male adapter...you will use a 1/2" IPS X 3/8" compression angel stop and I would suggest a 1/4 turn stop. Use Teflon tape on the threads.
That fitting in the previous picture shows a similar type on a new shower valve I put in. I just got around to checking today and I have some leaks. I used teflon tape. Will the leaks stop eventually?
Terry
08-11-2008, 05:16 PM
Will the leaks stop eventually?
Doubtful.
I would pull them and reinstall.
Redwood
08-11-2008, 05:24 PM
You used a connector like the one I pictured above to install a shower valve?
The one I pictured is for a toilet! It is not supposed to be used inside a wall.
The leak will not stop thats pretty much guaranteed...
Can you post a picture of it?
Terry
08-11-2008, 05:40 PM
A flex connector?
No way.
And you can't use tape with connectors. The tape will prevent it from sealing.
rpaquet
08-11-2008, 07:23 PM
Great! This is a very responsive forum. The picture I attempted to refer was with the 1/2" male copper adapter on the end of copper pipe. I just took a picture of my valve. Can someone help me post it?
Redwood
08-11-2008, 08:36 PM
Click on post reply then click on the paperclip next to the smiley faces to attach the photo.
rpaquet
08-11-2008, 09:09 PM
This is a shot from the bottom of my shower valve. The water can be seen on the wood.
Redwood
08-11-2008, 10:01 PM
Oh I thought you were saying that you used the braided stainless there.
I would get a repair coupling (coupling without a stop) cut the pipe, undo the leaking connection, wrap it with teflon tape, then apply teflon paste over the tape, tighten it back up and sweat the repair coupling.
The belt and suspenders appproach keeps me from going back and redoing things.
rpaquet
08-12-2008, 10:38 AM
Oh I thought you were saying that you used the braided stainless there.
I would get a repair coupling (coupling without a stop) cut the pipe, undo the leaking connection, wrap it with teflon tape, then apply teflon paste over the tape, tighten it back up and sweat the repair coupling.
The belt and suspenders appproach keeps me from going back and redoing things.
I lead you to the wrong post. There was an earlier post that I attempted to indicate.
Would it make sense to get the tape out of there and just use the paste? This is just my curiosity going wild since I am a newbie plumber. But I have no problem following smart direction.
jadnashua
08-12-2008, 10:50 AM
The tapered pipe fittings we use here have what is called an interference fit. The threads will leak once you have a good mechanical connection - you need something to fill in between the threads so it can't leak around them. Pipe dope flows, and if you apply it properly should work fine. Teflon tape makes it easier to thread things together to make the mechanical connection, but if not applied properly (not enough wraps, or not the proper direction), it won't fill in enough to block the flow past the threads. So either one by itself should work. Some people use both...one helps back up the other.
The quality of threads on the fitting can affect how easily it can be sealed...many of today's fittings have really lousy threads - torn up, made by a dull cutter, and may not be to spec, so sealing is harder.
rpaquet
08-12-2008, 11:04 AM
The tapered pipe fittings we use here have what is called an interference fit. The threads will leak once you have a good mechanical connection - you need something to fill in between the threads so it can't leak around them. Pipe dope flows, and if you apply it properly should work fine. Teflon tape makes it easier to thread things together to make the mechanical connection, but if not applied properly (not enough wraps, or not the proper direction), it won't fill in enough to block the flow past the threads. So either one by itself should work. Some people use both...one helps back up the other.
The quality of threads on the fitting can affect how easily it can be sealed...many of today's fittings have really lousy threads - torn up, made by a dull cutter, and may not be to spec, so sealing is harder.
My copper fitting supplier (Home Depot) just informed me to at least use paste in addition to tape. Their parts are coming from China some with an inadvertent small spine or grove running across the threads.
So, what is the proper way to apply tape?
Redwood
08-12-2008, 11:24 AM
Wrap it around the fitting in a direction that will not try to undo as you thread it in...
Cover the threads with a couple of wraps of teflon tape then put teflon paste over it.
rpaquet
08-12-2008, 06:04 PM
Just as I prepared to tear my project apart in order to apply teflon paste to the connectors, I noticed the leak has almost stopped. I had left the entire water system in the shower under pressure with a drip pan catching water.
I am going to leave it under pressure for awhile longer and see what happens.