Plumbing: are compression fittings leakproof?

[e9999]

may need to revamp some lines coming out of the wall for optimized arrangement.

I would like to cut them pretty close to the wall and use a compression ball valve or union there because unsure about sweating it in so close to the wall (sheetrock under plaster?) with unknown things touching the copper pipe in there, so thinking compression.

But don't want to do that if the compression fitting (I mean one of those "ring" types) is likely to leak at some point.

How good are these fittings? As leakproof as sweated copper fittings? And this is a one-time shot, right?

 

[Toyo FJ40]

Compression fitting are ok as long as they don't move. I like to use a teflon based pipe dope and dope the inside and outside of the compression ring before I assemble it. This helps the ring compress evenly it's less likely to leak. (slide the nut and ring on the pipe, dope the end of the pipe and slide the ring down over the dope and then dope the outside of the ring) I know some people say not to dope them but I've had almost no failures since I started doing it.

If you have the space you might be able to sweat a male adapter on the pipe so you could thread a valve on.

 

[e9999]

Compression fitting are ok as long as they don't move. I like to use a teflon based pipe dope and dope the inside and outside of the compression ring before I assemble it. This helps the ring compress evenly it's less likely to leak. (slide the nut and ring on the pipe, dope the end of the pipe and slide the ring down over the dope and then dope the outside of the ring) I know some people say not to dope them but I've had almost no failures since I started doing it.

If you have the space you might be able to sweat a male adapter on the pipe so you could thread a valve on.

thanks, interesting about the dope.

well, the whole point of putting in a compression valve would be to put it close enough to the wall where sweating a fitting may be iffy. I'm thinking anything within 2 or 3 inches of the wall may be a bad idea.

 

[pjfairchild]

Go to Home Depot or Lowes (or a real plumbing supply house to save $) and ask for a Shark fitting. Presses on to your pipe and 'bites' with SS teeth. Completely leakproof and removeable if you buy the
$0.75 plastic tool to do so. They are made for exactly what you are doing, that's how the 8 hour bathroom remodeler replaces the whole room so fast.

 

[fj40charles]

t I'm thinking anything within 2 or 3 inches of the wall may be a bad idea.

Nothing wrong with sweating that close. Get a torch with a small head on it. I would not use a shark fitting or compression fitting if you want something that will not leak in your lifetime.

 

[splitshot]

Go to Home Depot or Lowes (or a real plumbing supply house to save $) and ask for a Shark fitting. Presses on to your pipe and 'bites' with SS teeth.

These are good if your plumbing has any flex behind it. Kinda like a mini dresser coupler. I'd rather sweat it if at all possible though..

 

[Toyo FJ40]

thanks, interesting about the dope.

well, the whole point of putting in a compression valve would be to put it close enough to the wall where sweating a fitting may be iffy. I'm thinking anything within 2 or 3 inches of the wall may be a bad idea.

You can sweat right up to the sheetrock, just a question of how much you want to burn the paint. I mentioned the male adapter because some times when the pipe is flush with the sheetrock you can put a male adapter on and apply the solder to the inside when you heat it. It will flow out to the fitting edge in the wall.

If you have 3" then you should have no problem soldering on a valve.

 

[e9999]

Go to Home Depot or Lowes (or a real plumbing supply house to save $) and ask for a Shark fitting. Presses on to your pipe and 'bites' with SS teeth. Completely leakproof and removeable if you buy the
$0.75 plastic tool to do so. They are made for exactly what you are doing, that's how the 8 hour bathroom remodeler replaces the whole room so fast.

those don't exactly have the 20 years history yet I'm guessing (or do they?)

 

[e9999]

Nothing wrong with sweating that close. Get a torch with a small head on it. I would not use a shark fitting or compression fitting if you want something that will not leak in your lifetime.

what if there is something combustible touching the pipe right inside the wall? you guys are braver than I am... already lost one house in a fire, that's enough for me...

 

[Toyo FJ40]

what if there is something combustible touching the pipe right inside the wall? you guys are braver than I am... already lost one house in a fire, that's enough for me...

You can wet down around the pipe before you start but with 3" you should be fine. If you get the pipe hot enough to start a fire than you over heated the joint and burned out the flux.

Use a spray bottle with water in it and spray it in the hole around the pipe and then use it to cool the pipe when you're done.

 

[e9999]

You can wet down around the pipe before you start but with 3" you should be fine. If you get the pipe hot enough to start a fire than you over heated the joint and burned out the flux.

Use a spray bottle with water in it and spray it in the hole around the pipe and then use it to cool the pipe when you're done.

I'm no expert so overheating is definitely a possibility

Clever, spray inside the hole a lot. Yea!

 

[jjbodean1970]

get one of the flame-resistant cloths they sell and cut a hole in it small enough to fit over the pipe, do your sweating while protecting the rock and when done and its cooled just pull the cloth back over the pipe and new fitting.