Plumbing Question: Flare Fitting vs. Compression Fitting

[Angela]

I need to replace my galley faucet, and it is hard plumbed straight from the faucet into the copper lines with a flare fitting. There is no shut off valve like you find in a house, but I'd like to add one when I replace this faucet to make it easier to replace it again when I find the faucet I really want.

Hatteras used flare fittings throughout the boat, but I cannot get this fitting loose. Even using two wrenches, it won't budge, rather, it just wants to twist the rest of the lines. So, I'm considering cutting the line running to the fauce, beyond the flare fitting and using a compression fitting to install a shut off valve and then I can easily connect the new faucet from there.

Question: Is there anything wrong with using compression fittings here? Hatteras chose flare fittings and I'm not sure where there was a particular reason for that or whether that's just they way they did it as a matter of choice. Since I cannot get the pipe out to work on it, and because it is located behind the garbage disposal, it's a bit of a tough place to work in the first place.

Thanks for your opinions.

 

[thoward]

I used compression fittings and a brass shutoff valve on my 43 Egg without any problems. I attached to the faucet using the stainless braided hose.

 

[Liquid Asset]

Angela, Why not re Flare the tube after you cut it? You can buy a flare tool for $20 at homeless depot and make it look factory. at that time, you can even add a shut of valve. Our sinks have them, but I do not know if they are factory or not.


It is very easy to flare the tube, you just have to take your time. buy an extra piece of tubing and practice a couple times before you do it to the real part.

 

[egaito]

Angela, Why not re Flare the tube after you cut it? You can buy a flare tool for $20 at homeless depot and make it look factory. at that time, you can even add a shut of valve. Our sinks have them, but I do not know if they are factory or not.


It is very easy to flare the tube, you just have to take your time. buy an extra piece of tubing and practice a couple times before you do it to the real part.

I'm not a big fan of flare fittings on boat. If there's any movement or vibration, it seems to "work" the metal.

I don't dislike them enough to go removing any left-overs (if it ain't broke, don't fix it), but when the fitting needs to be worked on, I like to go to a compression fitting, then to flexible tubing, which makes everything easy to locate and fasten down.

 

[Angela]

I am wanting to go the compression fitting route, if there is no reason not to, because of lack of access (like everything else on a boat) of being able to get to the pipe (I can't take it out and work on it on the table), and I have compression fittings on hand. I basically have to put my arms around each side of the garbage disposal (or rip it out which I don't want to do either) and work behind it so I'm wanting to do it in a way that I already know - I could do the compression fitting with blinders on; I've never flared a pipe. But, if there is a reason not to use compression fittings on a boat, I'd like to know that.

I'm trying not to make an all day project out of this. It gets more complicated for me if I have to go out and buy a new tool, learn how to use it, and then try applying a concept that new to me in an area where I can't reach well. Just trying to keep it simple, really.

 

[Paul45c]

Absolutely no reason to not go with compression fittings on a boat. You see them on boats all the time. They're tough, and if there's any negative associated with them, if not done right they can weep a tiny bit. I've only seen that on houses with extreme water pressure, though; you certainly won't have that problem on any cruiser with pumps supplying your water.

 

[yachtsmanbill]

Last spring I had the dubious pleasure of removing the quick disconnect deck fitting from the HATT TRICK and ended up twisting the copper tube about an inch below the fitting. No sweat-- I'll just throw a comp. fitting on with a new perko fitting and be good to go--NOT!! At least THAT length of tube had an O.D. about .010-.015" bigger than standard. The ferrul would not go on. I ended up re-using the original fitting after a tough removal (even with the fitting in my hands!) and re-flared the tube. At that point, I also installed a length of SS braided 1/2" washing machine supply hose. All that did was to simpify installation of the deck fitting. The original copper was pretty stiff. A freind suggested that the original may have been either high pressure copper or even a metric size; AND THAT BOY IS A SHARP KNIFE !!
Standard on tubing is K or M - k has a very thin wall - and the m is quite heavier for use in refridgeration. I dont know what Hatteras used, but it is/was a bastard size. I even MIKED it at several places along its length at least up to the regulator, and it read the same. Probably not expanded from pressure of freezing. Go with the flare. That what is used for the water service and FUEL (ABS code).
Take your time and try to eliminate any "pipe strain" which will help eliminate
failures. ws

 

[Will]

Angela,

Compression fittings are not as reliable as flared fittings and are usually a one shot deal. The Coast Guard prohibits their use in fuel systems on passenger boats.

I'd never use compression fittings for anything unless there was no other choice. However, if you prefer to use them in your freshwater system where problems might cause a mess but likely not sink the boat you are probably OK.

Will

 

[GaryNW]

I would go compression for a couple of reasons. Flaring streches the copper quite a bit and you need both the ID and OD to be clean, well preped and burr-free. I believe old soft copper is not as soft as new soft copper- making the flaring process less reliable and more difficult to do. The other reason is what you have already alluded to, Ang. Easier to do esp in tight access situations. For prep, all you need is a clean OD (brillo pads could do this).

As I recall my aircraft repair specs (manuals), we offered about 7 ways to repair tubing-including fuel, water and 3000 psi hydraulic. Compression ftgs by a variety of suppliers were the norm. A few methods involved proprietary swaging ftgs and tools- but hey, thats just high end compression ftgs.

Gary

 

[doc g]

The reason flares are used is that they are better in situations where the pipes are subjected to possible vibration or movement (read boat). Can you get to the pipe elsewhere? What if you cut it in another place (under the floor?)and then replace the section under the sink. You could also install your shut off valve there if it would be more accessable.........Pat

 

[jim rosenthal]

Ang, I would use compression fittings and flexible lines if you want to. I did that on my head sink replacement and it has worked out fine.

Incidentally, the tool that you may very well need to get the faucet in and out is called a basin wrench. They sell them at Home Despot. It makes the job of removing or installing a faucet worlds easier- I speak from experience.

 

[Bob Bradley]

If you do decide to re-flare the existing line, do not use the "garden variety" Home Despot flare tool. Go instead to a reputable plumbing house and get a professional quality flaring tool. You'll be glad you did.

 

[Traveler 45C]

Incidentally, the tool that you may very well need to get the faucet in and out is called a basin wrench. They sell them at Home Despot. It makes the job of removing or installing a faucet worlds easier- I speak from experience.

I got one of those wrenches but couldn't use it. I needed to pull all 3 faucets and I only had enough room to get a bite on the nuts with no room to turn them. I had to pull the sinks to get the faucet off.