A garbage disposal flange is the part of the unit that connects it to the underside of the sink drain. It screws onto the drain and then holds a mounting bracket for the garbage disposal. There are generally three screws that are used to hold the disposal to the flange.
When there is a problem with the garbage disposal chances are very good that you will need to remove it from the flange in order to work on it or replace it. This is not a difficult process, but there are some things you want to remember to make the job easier.
1- Turn Water and Power Off
Before working on any part of the garbage disposal system you should shut off the water. This will ensure that you do not get flooded out as you remove the disposal unit. Also, before removing the flange from the drain pipe, run the faucet to let the water run out of the pipes. Be sure to turn off the electricity as well.
2- Do Not Force a Rusty Issue
If the garbage disposal flange has been installed for several years, you may find that there is going to be considerable rust. This rust will hold the flange in position which will make it very hard to remove. Many do-it-yourself-ers will try to force the flange free by using a large plumber's wrench. This is a mistake as it can twist the pipe, warp the flange, or even crack the underside of the sink.
When faced with the issue of a rusted disposal flange the best thing to do is to use some penetrating oil on it. Shake the can and then spray it on the flange. Let the oil sit on the flange for a few minutes. This will allow the penetrating oil to work on the rust to free up the flange without twisting or breaking pipes. Then use a pair of slip joint pliers to turn the flange.
3- Pry Flange with Flat Screwdriver
The flange is going to be seated in the bottom of the sink, or directly under the drain. In order to remove the top ring of the flange you will need to use a flat screwdriver to pry it up. Work around the flange in small increments to make sure that you do not bend it. If the flange is bent then it will not be able to be reused.
4- Remove Old Putty
One of the things that will remain when you remove the old disposal flange is the plumber's putty. Make sure to remove it with a flat scraper before you replace it. You will also need to remove the putty from the disposal flange if you are going to reuse it. If it is left on the surface it will interfere with the way it sits.
5- Do Not Let Disposal Weigh It Down
Before you remove the disposal flange you must first release the weight of the garbage disposal from it. The three retaining screws are removed and the disposal unit lowered to the bottom of the cabinet before any work on the flange should begin. This will lighten the load on the part as you work on it.