OK, so I've been remodeling bathrooms, and one of the things I put on the to-do list is replacing the old water line shut off valves. They're the compression type, which is pretty common in residential applications. I've struggled with these before, and I never really was successful in finding a good how-to. So here, I'll tell you what I did.
I've seen tips on how to use heat, pliers, lubricant, special tools, etc etc to remove the old compressed ferrule once the valve is off. None of that is easy to do when the ferrule is compressed onto the water line so close to the wall that the nut barely has room to wiggle, which is how my home builder left it.
Here's what I did. It's cheap, it's terribly easy, it's fast, and it's very effective, and most importantly, it will cause absolutely no damage to your water lines. All you need is a 10-pack of standard 1/4-inch flat washers from your local hardware store. Though I'm 99.9% sure you won't have any fitment issues with 1/2 inch copper water lines, I would suggest taking the old valve body with you to the hardware store to check the fit of the washers. You want to find a washer size that fits the internal opening of the valve body where the compression ferrule mates to the valve. I'll try to post some pictures to make the step-by-step clearer.
Tools Required:
Work Gloves
Vice Grip pliers
Channel Lock pliers or adjustable wrench
Old valve body
10-pack 1/4-inch flat washers
There's one thing you need to understand about compression fit valves. That brass ring, aka ferrule, is placed under so much pressure between the valve body and the nut that the ferrule actually reduces in diameter. Likewise, the soft copper tube beneath it also reduces diameter beneath the ferrule. So, this means that no matter how you twist, pull, push, or pry, you will likely never manage to pull that little bugger off the pipe without a special tool to help you. This blurb explains how to create that tool for about $1.00.
Once you remove the old valve body (I'll assume you know how to do that since you've come to the point that you can't remove the old ferrule), take two of the washers you sized to fit your valve opening and place them flat inside the valve where the copper pipe normally inserts. Effectively, you're making the valve-to-pipe mating surface shorter.
Now, thread the valve back onto the nut and tighten down nearly all the way. Do not tighten the nut down all the way, just get close. If you run it all the way to stop, you'll compress the ferrule again, making the last step more difficult.
Remove the valve again. Add two more washer. Thread the nut back on to the valve body, stopping just short of the bottom. Remove the valve.
Repeat this process until you've pulled the compression ring all the way to the end of the pipe. At this point, loosen but do not remove the nut. You want the valve to have enough play to wiggle back and forth a bit without coming free of the nut.
If you're not already wearing your gloves at this point, it would be a good time to put them on. Grip the valve body securely, pull hard, and wiggle it left, right, up and down. At this point, if you've wound the nut all the way to stop on the last round, you'll probably have to get violent to close those last couple of millimeters, or break out some other tools. But if you spared that last half turn, this should be fairly painless, just wiggle and pull the ferrule the rest of the way off the pipe.
Simple as that. Email me if you have any questions, and I'll see if I can't get some pictures up soon to help illustrate.
God bless!
