Installing a Compression Valve

  • 01 of 06

    Installing A Compression Valve

    A compression valve
    Aaron Stickley

    A compression valve is one of the easiest and quickest shut-off valves to install if you have copper piping in your house. If the existing stop valves have sat unused for years, the chances are that they may not work perfectly or at all when you go to use them. That is why it is always a good idea to replace the valves when you replace a toilet or faucet. Replacing a compression valve will help ensure that it will work when you need it.

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  • 02 of 06

    What You Will Need

    What you need to install a compression valve
    Aaron Stickley

    The things you will need to install a compression valve are:

    • New compression valve - When purchasing a compression valve(s) verify the size required by checking the flex line, you will be installing. Many faucets now come with built-in flex lines (especially kitchen faucets), so you should make sure to have the right size angle stops before you begin.
    • Pipe joint compound - A dab of pipe joint compound on the threads will help the valve tighten just a bit better and make it easier should you ever have to remove it.
    • Pliers - Two pairs of pliers are needed; one to hold the valve and one to turn the compression nut.
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  • 03 of 06

    Compression Valve - Shut Off The Water

    Main Shut Off Valve
    Main water supply to the house. Aaron Stickley

    The first step is to shut off the water supply to the house. If you are only replacing a hot side stop valve, then you could shut off the water at the water heater, but most likely you will be replacing both the hot and cold sides or maybe just the cold side when changing the compression valve for the toilet.

    Note: There will be some residual water in the pipe, so it is a good idea to have a small bowl, sponge, or towels handy when removing angle stop valves.

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  • 04 of 06

    Remove The Old Valve

    Remove an old compression nut
    Using a compression sleeve puller to remove compression nut. Aaron Stickley

    Remove the old valve, brass sleeve, and compression nut from the pipe. With one pair of pliers hold the old valve and with another set of pliers unscrew the compression nut.

    With the old valve out of the way, you can remove the old brass sleeve and compression nut from the pipe. A ​compression sleeve puller could come in handy if you have trouble removing an old brass sleeve and nut.

    Note: Many times the old compression nut will fit the new valve, and you could then just tighten the new stop valve on with the old sleeve and nut. The fit can be tested test by putting the new nut onto the old valve, and if it threads on easily by hand, it is the same thread.

    But it is always a good idea to change all of the pieces, particularly when the old valve is quite old and worn.

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  • 05 of 06

    Install The New Valve

    Installing a compression valve
    Aaron Stickley

    Once everything is off the copper pipe place the nut on the pipe slide it back then place the sleeve on. Push both pieces back to make room so you can push the angle stop on as far a possible. Now push the angle stop valve onto the pipe as far as you can. Apply a small amount of pipe joint compound onto the threads of the compression valve.

    While holding the angle stop valve in place slide the nut and sleeve all the way up to the valve and thread the nut on as far as you can with your hand. Use one pair of pliers to hold the compression valve where you want it to face and another set of pliers on the nut tightening it firmly. The nut should turn about a ¼ of a turn after it has been tightened by hand.

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  • 06 of 06

    Check For Leaks

    Turn off the compression valve if it isn’t already in the off position. Turn the water back on and check for leaks. If it looks like the compression valve is holding the water without leaks, then continue hooking up you flex lines.

    Compression valves can sometimes have a slow leak, and it is always a good idea to check back an hour after installation and sometimes even the next day to make sure it is not seeping. If you notice a leak shut the water off, remove the pressure from the line and then try to tighten the compression nut a little more and recheck it.