Compression fitting faucet valves

[getnit1]

I have used this forum for a lot of advise while redoing my bathroom. I appreciate all of the time everyone takes to anser and help. I have gutted my bathroom to the floor joists, wall studs and ceiling studs. I wanted to move the tub and relocate the toilet. The sink counter is going in the same place. I have 2 questions. I usually sweat everything and have thus far. My orriginal sink was a single and I am putting in a double. I am running new water lines that I will T into the existing copper and move over about 24" for the new sink. I was goint to leave my original valve stubouts in place and replace the galvanized with brass nipples and screw on valves. I have 2 compression valves that I thought about using for the new sink. First question can I put everything together with the compression valves pressure and leak test for a few days then take the compression valves back off leave the nuts and ferules and then reattach the valves after installing the wall back in place. I have never used a compression fitting valve before. Second question my drain line will be moved about 24" also it is horizontal in the wall it is 1-1/4 copper and I am goint to center it in the cabinet. I have called plumbing supply stores and plumbers noone has 24" of copper that I can buy. The only thing I can find is a 20' joint 126.00 so I am going to go pvc 1-1/2 I purchased a rubber adapter to go from 1-1/4 to 1-1/2 is this a bandaid or will it hold? Thanks!

 

[Jadnashua]

If you don't over-tighten the compression fitting, you should be able to do what you want. But, if you are going to be putting in brass nipples, I'd just get a threaded shutoff. If the pipes really are galvanized, I'd take this opportunity to at least cut it back to where you can get at it easier after the remodel so you don't have to tear our your new stuff when it clogs up and starts to leak, an inevitable result, eventually. Replace what you can with copper or something else while you have things torn up.

A no-hub connector is fine to transition between pvc and copper. I'm not sure if the ones typically stocked in the big box stores are the right size, though. They are usually sized for CI to pvc. They are made, though. These are the ones with a band to support the ends of the pipes to keep them in alignment, not the uncovered big rubber band that is used underground, where the backfill provides that funtion.

 

[Sponsor]

 

[getnit1]

thanks for the response. The compression valves will be going on the new 1/2" copper stubouts. I am reusing the original 2 valve locations which have 90's that have galv nipples, I am replacing those galvanized nipples with the brass nipples. I was just going to cut into the original copper pipe where it comes up about 24" in the wall T into it about 16" high for one and 18" on the other from the floor and go horizontal about 24" then 90 out with 2 stubs these are the stubs i will put the compression valves on for the second sink. I was going to sweat a winged female threaded 90 on these also but I already have the compression valves. The guy at the plumbing supply store (not a box store) tried selling me a valve with 2 outlets and told me to use 2 hoses with a brass fitting in between them to connect to get enough length to get to the other faucet (he only had 24" hoses). Then he told me that it would increase the volume supplied to the faucet because of the total volume contained in the two hoses is more than the single hose and that I would not notice a reduction in volume with both faucets on at the same time. This is the guy that told me that the compression valves would be better so now I am scared of them.

 

[Jadnashua]

A compression valve, properly installed, is a fine, long-term option. A little oil on the threads makes it easier to judge when it is tight enough. Overtightening is the biggest mistake - this distorts the pipe and can make it difficult to remove and if really cranked, can create leaks.