Sweat or Compression?

Teamo · Jul 11, 2005

I am about to do the finish plumbing in my bathroom remodel project. I have copper stub outs for the vanity and the toilet. What is the best shutoff to install? Should I solder on the chrome plated shutoffs, or use the compression type? I have relatively high pressure in the house, (about 80lbs) and I was worried that the compression type might leak.
Thanks Jim

Terry · Jul 11, 2005

Compression stops are the way to go.
Just use light oil on the threads.
I've seen houses with 125 PSI using compression.
That was pretty high, so after a few years the homeowner installed a PRV on the incoming cold.

There are many problems with soldering a stop. Most plumbers use the compression.

Sponsor · 2022-01-29T12:20:58-0800

Lithnights · Mar 11, 2006

Terry said:
Compression stops are the way to go.
Just use light oil like WD40 on the threads.
I've seen houses with 125 PSI using compression.
That was pretty high, so after a few years the homeowner installed a PRV on the incoming cold.

There are many problems with soldering a stop. Most plumbers use the compression.

What is meant by "There are many problems with soldering a stop. Most plumbers use the compression."

What is "soldering a stop"? Does that mean any type of shut off valve?

Thanks,

Dunbar Plumbing · Mar 11, 2006

lithnights said:
What is meant by "There are many problems with soldering a stop. Most plumbers use the compression."

What is "soldering a stop"? Does that mean any type of shut off valve?

Thanks,

"soldering a stop" is the same termage as angle stop/straight stop < both are valves

I've had great difficulty with soldering even the 1/4 turn shutoffs, even holding the flame on the pipe and letting the heat travel that way into the socket, still have leaks with the valve in the off position. I figure the teflon packing is so small in there to begin with that the heat distorts the gland.

And yes, I sweat in the open position, absolutely do not move the handle until the valve is cool. Still leaks. Compression valves are common for my installs.

Lithnights · Mar 15, 2006

How about when installing a main shut off?

I want to install a new shut off valve (ball valve) for my main water line. The current one (looks like a gate valve) works but it is 50 years old so I figured I might as well put a backup one in just in case.... especially since I sometimes feel water on it when I turn it.

1) Is sweat or compression preferable here or doesn't it matter?

2) How would someone actually replace (not install a new one upstream) a main shut off valve? How would they get the water turned off? Call the water company?

Thanks,

Kristi · Mar 15, 2006

WOW RUGGED! I've been gone awhile, but that is one flashy avatar you've got there, lol!

you would solder your new shut off valve in the main line... you would rent or borrow a key to shut off the city side valve by the sidewalk or property line 1/4 turn (is it the same in the States as Canada? I would think so...) and cut in your new valve. Or you could shut the 50 year old valve, drain the line, cut into the copper upstream and solder away at your new one... it will suck if you have any water coming back at you, so if the new valve isn't taking that's why. The reason this is fine or different from soldering stops is that this valve is a proper sweat one that fits snuggly to the copper in the middle of the line. I have found the stops can also be a little loose on the stub outs which would make it pretty difficult for the solder to take, forget those ones and stick to compression type like all those pros are saying.

recipe for you:
solder within copper lines
compression on the ends of copper lines for supply tubes

Lithnights · Mar 15, 2006

I will follow your advice on soldering a new shut off valve for the main..

but for fixture shutoffs... are we saying that there are compression shut offs and normal (to be soldered) shut offs? The standard shutoffs I have used have a non threaded input where the 1/2" copper goes. I then solder it.

Do the compression shut offs have a threaded end? I guess I can't picture them. I am heading to the store tonight to look into this but wanted to get your feedback in the interim.

Anyone have a link to pictures of each (compression vs. not) so I know what I am looking for?

thanks!

Jadnashua · Mar 15, 2006

A compression fitting relies on a ring around the pipe which is tapered. You tighten up a nut which pushes the tapered ring and creates the seal at the back of the valve housing. No sealant is required or should be used. It does work better if you put a little lubricant on the threads while you are tightening things up because it makes turning the nut when it starts to get tight a little easier. Many companies make them, but one of the more commonly available ones in the US is from www.brasscraft.com.

SteveW · Mar 15, 2006

Now a new contender on the choice of how to attach a stop -- check out BrassCraft's "What's New" section of the website. They've got a new system called SureConnect where a copper stub-out has a ridge that the stop clamps down onto -- they say replacing a stop will be extremely fast with this new system.

http://www.brasscraft.com/Default.aspx?Page=NewProducts.aspx

Lithnights · Mar 15, 2006

jadnashua said:
A compression fitting relies on a ring around the pipe which is tapered. You tighten up a nut which pushes the tapered ring and creates the seal at the back of the valve housing. No sealant is required or should be used. It does work better if you put a little lubricant on the threads while you are tightening things up because it makes turning the nut when it starts to get tight a little easier. Many companies make them, but one of the more commonly available ones in the US is from www.brasscraft.com.

What's the difference between sealant and a lubricant? I have seen tons of messages here that go back and forth on whether to use dope or not. Still no clear answer there.

Do you consider wd-40 a lubricant? And consider dope to be a sealant?

Jimbo · Mar 15, 2006

WD 40 is NONE OF THE ABOVE. It is a solvent and water dispersal agent.

Pipe dope is primarily a sealant; some, especially the teflon pastes, do not set hard. I use teflon paste on compression ferrules and threads with good luck . Others prefer 3-in-one oil, or simple faucet grease. We ae usually split down the middle, 60/40, on this one.

Lithnights · Mar 16, 2006

jimbo said:
WD 40 is NONE OF THE ABOVE. It is a solvent and water dispersal agent.

Pipe dope is primarily a sealant; some, especially the teflon pastes, do not set hard. I use teflon paste on compression ferrules and threads with good luck . Others prefer 3-in-one oil, or simple faucet grease. We ae usually split down the middle, 60/40, on this one.

I have noticed that split after reading through dozens of posts on this issue. Usually that tells me, it doesn't matter which one since both will work!

Cass · Mar 16, 2006

I do not like compression anything. I like sweat or threaded. When repairing leaks in homes the leaks from comp. fittings out number any others by far. Maybe it is the fault of some home owner / DIYer that didn't know what they were doing but I just don't like them. Just me I guess.

Lithnights · Mar 16, 2006

Cass said:
I do not like compression anything. I like sweat or threaded. When repairing leaks in homes the leaks from comp. fittings out number any others by far. Maybe it is the fault of some home owner / DIYer that didn't know what they were doing but I just don't like them. Just me I guess.

I am learning that the plumbing business is far from black and white. Sealant vs. non-sealant when doing compression.... sweat vs. compression etc..
It always seems to be right down the middle.

After reading multiple posts here about how so many posters prefer compression for connecting to fixtures, I go to HD and talk to a 30 years of experience plumber who says he never uses them (not even on fixtures) and wouldn't recommend (much like Cass states here). Who to believe!?!?!

I guess I'll just go with what I know and hope for the best.

Jimbo · Mar 16, 2006

San Diego is the 7th or 4th largest city in the country, depending on whether you actually count ALL the residents. I have not personally ever seen a sweat angle stop. None of the hardware stores even sell one. I never asked for one at A.O. Reed or Fergusons. I guess they might have one if you asked. But there are tens of millions of compression valves in place.

On properties built before the war (II) or just after, it is galvy. They started using copper in the early 50's here, and it seems like it was compression for the get-go.

Compression valves are extremely reliable.

Dubldare · Mar 16, 2006

Where I come from, only mechanical (ground, flanged, or threaded if above ground) type joints are allowed on service valves. Basically, water flare on residential services, flanges on larger diamerters (2"+). A compression fitting is not approved, nor a soldered (brazed or soft) is allowable for the meter valve. After the meter, just about anything goes.

I think the idea is durability and ease of replacement.

Bob NH · Mar 16, 2006

I have a couple of angle stops that a professional plumber installed in the original construction in early '65. The name STERLING is stamped into the bonnet of the valve. They are still operable and still shut off tight. The 1/2" copper that comes through the wall looks like it's tin plated and is swaged down to near an actual 0.50" diameter where it's soldered into the valve.

Jadnashua · Mar 16, 2006

When I redid my kitchen, I had them put in soldered shutoffs under the sink. I would have done it myself, but in the city I live in, a licensed plumber is required. Compression, I'm sure would have been fine, though. I don't expect to be here if they ever need replacing, though. HD has compression, solder, and threaded ones. They don't carry the inserts required for a compression fitting on pex, though.

ToolsRMe · Mar 17, 2006

SteveW said:
Now a new contender on the choice of how to attach a stop -- check out BrassCraft's "What's New" section of the website. They've got a new system called SureConnect where a copper stub-out has a ridge that the stop clamps down onto -- they say replacing a stop will be extremely fast with this new system.

http://www.brasscraft.com/Default.aspx?Page=NewProducts.aspx

OOOO this looks very interesting! ... since I'm installing two sinks and a toilet. I'm worried, though, that his fitting won't exist in ten to fifty years.

Any thoughts?

Plumber1 · Mar 17, 2006

valves

Solder or compression. Use either one and get on with it. Put them on carefully and you won't have any trouble.
Oil, grease or Teflon paste, what ever blows your hair back....

Sweat or Compression?

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