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Using compression fittings vs soldering

Posted by xmsm (My Page) on
Mon, Oct 27, 08 at 21:28

I have a 9 ft. run of copper water line feeding my dishwasher from the sink supply. Line was originally soldered (30 yrs ago.) past the shutoff valve but I need to remove the line to remove the kitchen cabinets, then reinstall it once the new cabinets are in. If I cut the copper 4-6 inches past the shutoff and install compression fittings to reconnect it, are the odds in my favor of having a solid connection using compression fittings? I had success at the dishwasher end when I recently installed a compression fitting for the stainless flex supply line and would hope that this would work too. Other than the possibility of operator-error, is this a good plan?

Follow-Up Postings:

RE: Using compression fittings vs soldering

If the new line will run through the cabinets where it can be seen when the cabinet doors are opened you may use compression fittings. If the line will be concealed under or behind the cabinets you must solder the joints.

Code prohibits compression joints in a concealed location.

Compression joints are easy to install and very reliable if installed correctly however you must be sure to use an approved tubing cutter to cut the copper.

RE: Using compression fittings vs soldering

Thanks Lazypup. The joint will be accessible via the sink base cabinet, so no problem there. Is a mini-hacksaw acceptable or should I just get the tubing cutter?

RE: Using compression fittings vs soldering

copper should never be cut by any means other than a tubing cutter.

When copper is cut with a tubing cutter the rotating action helps maintain the tubing in perfect roundness. When cut with a saw the ripping action of the saw will tend to distort the copper slightly out of round.

There is only 0.001" clearance between the tubing and a fitting. If the copper is even slightly out of round it is extremely difficult if not impossible to make up the joint.

My favorite cutter is a Superior Tool "Proline" mini cutter available at Lowes, HD and most hardware stores. Expect to pay about $10 for it, but i can assure you it is worth its weight in gold when you have to make cuts in tight places.

Imperial Eastman also makes a professional grade mini cutter but they are generally only found in HVAC supply stores.

When looking in your hardware you will also see a small red mini cutter for about $5. Take a tip from experience, unless you are in dire need of a fancy weight for your fishing line, don't waste your money.

RE: Using compression fittings vs soldering

Are compression fittings acceptable on
copper tubing to copper tubing
copper pipe to copper tubing
copper pipe to copper pipe?

RE: Using compression fittings vs soldering

Well, they have to be accessible. The fitting only connects ONE thing (tubing or pipe) to a fixture. You can get fixtures that go between all those things (unions, tees, elbows, etc..).

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