The ice maker line to my refrigerator currently has no shutoff valve and I'd like to add one but I can't figure out what size the connector is. I purchased a 1/4 inch valve since the ice maker connector I have says 1/4 FCM on it but it did not fit. It looks more like 1/8 inch, but a 1/8 inch valve doesn't fit either, although it is very close. Where can I find information about water pipe sizes, there must be some standard?

My fridge is a GE CFCP1NIZSS: http://products.geappliances.com/ApplProducts/Dispatcher?REQUEST=SpecPage&Sku=CFCP1NIZSS

The copper water line I am connecting it to has the exact same measurement as the fridge.

This valve was extremely close in size, and just barely didn't fit: http://www.amazon.com/gp/product/B005C0J3XI/ref=oh_o02_s00_i00_details


Okay I thought that searching the internet for 1/4" OD Valve Male Female would get me what I need but I am getting no results so I've reopened the question! Can anyone give me a web link to a product that will fit? I've added a photo of the current connection where I'd like to add the valve. Thanks!

Photo of water connection

  • 1
    A make and model of the refrigerator might help, as this may be proprietary.
    – Tester101
    Commented Apr 10, 2012 at 11:37
  • 1
    maybe you are mixing up OD (outer diameter) and ID (inner)?
    – Steven
    Commented Apr 10, 2012 at 13:31

3 Answers 3


There are different standards to pipes and threads. Your issue is that you are trying to mix two different threaded standards.

The ball valve that you linked to has national pipe threads (NPT). NPT are tapered and it is that taper that makes the seal between a male and female joint. No washers are required.

What is shown in your photo is compression fittings which have a straight or running thread. The seal is made by either a ferrule or a rubber washer.

In your case, the connection between the copper tube and the supply hose has been made as follows:

1/4" Copper Tube > 1/4" Compression by 1/4" Compression Coupling > 1/4" Supply Hose

The seal on the copper tube is made by a ferrule that is located under the nut. As the nut is tightened, the ferrule is compressed between the coupling and the pipe.

The seal on the supply hose side is made by a rubber washer which is usually built-in the the nut of the supply hose. (The compression coupling would have come with two nuts, one of which has been discarded as the supply hose has one built-in.)

So, to answer your question, you simply need a 1/4" compression x 1/4" compression valve that will replace the current coupling. Here is a link to such a valve.

  • So I got the valve and it was ill equipped to handle the pressure. Water was flying out of the handle in every direction.
    – satur9nine
    Commented Jan 6, 2013 at 20:19
  • Did you try to tighten the nut on the top of the valve? Do you know what the pressure is?
    – pdd
    Commented Jan 7, 2013 at 16:14
  • I didn't try that, at that point it was 12am and I gave up on the project. I have no idea what the pressure is. I think at this point I should probably leave it to a professional. Apparently under the house there is an improper valve installed that should be removed anyway.
    – satur9nine
    Commented Jan 7, 2013 at 18:16

Do you have the paperwork that came with the fridge? It should show the ice maker install and maybe say the size of the valve. I have always seen it to be 1/4".

Where is the water line tapped from? Usually it comes off a 1/2" copper pipe. You could put your valve on the copper pipe side.

EDIT: Page 33 of the installation manual states that the water supply tube is 1/4" OD. You need a 1/4" valve. Be sure there are no burrs on the copper tubing after you cut it. Sometimes you need to file the edges. If the pipe cutter is not sharp it can mushroom the ends and that will make it seem that it is not the right diameter.

  • 1
    Also remember that usually the fridge supply lines are connected with compression fittings, so the 1/4" is OD. To confuse matters, if you are attaching a compression fitting to 1/2 pipe, usually you need a 5/8 OD fitting. Please don't use one of those piericing valves either!
    – Steven
    Commented Apr 10, 2012 at 22:23

If you have more time and money, the best thing is to run either a 1/2 inch copper line or a 1/2 galvanized line to the back of your refrigerator with a 1/4 inch connection on it, preferably set in the wall in plastic box. An alternate cheaper way is to run a 1/4 inch line from the 1/4 inch connection at your dual shut off valve under your kitchen sink. However, the copper line is a hard line and it gets crimped especially when you or someone else is careless in moving the refrigerator around to clean or whatever.

Using two crescent wrenches, here's what to do if you already have a hard copper line to the back without a shut off valve anywhere in site. You can buy a kit that has the parts you'll need, 1/4 inch connectors with a 6 foot, 1/4 inch supply hose, that has the 1/4 nuts on both ends. Carefully do it yourself or get a plumber to cut the copper line with a copper pipe cutter, a nice clean cut, a couple of inches this side of where the line comes out of wall or cabinet (as long as it's not crimped, you're ok to cut it).

Put the loose 1/4 inch nut on backwards on the pipe, so the nut covers the ferrel tucked in at the edge of the end of the pipe, then, screw on the 1/4 inch connector/adjuster onto it, with the 1/4 inch threads to the 1/4 inch nut on the hose, and tighten, snug, never overbearing, ever with any plumbing. Then connect the other end of hose/nut to the threaded end on the refrigerator at the bottom, snug! Remember! However, the best thing to do anytime you are connecting a line to either a faucet or refrigerator or whatever the case may be, before you put that last connection on the refrigerator, put that end in a big bucket and turn it on to clear the line of air and grub, because who knows how long it's been sitting. Plus, if you've got air in the lines, that's a whole nother headache, trust me you do not want! Get the air out! You can do all of this yourself too! Don't forget to check everything for leaks! Good luck! Now go celebrate you just saved yourself $150!!!

  • Jac, although potentially helpful, this doesn't really address the question, which was what size connector is needed to put a valve in the existing connection.
    – TomG
    Commented Oct 24, 2014 at 2:54

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