The chrome thing on your sink that looks like an upside-down juice glass is an air gap fitting for your dishwasher. An air gap fitting is a fixture that prevents dirty water from entering your dishwasher through the drain line and contaminating the dishes placed there. It also works with your drain line to protect your potable drinking water.
Air gap fittings are not only extremely important, but also required by plumbing codes to be installed on your drains. This is because air gap fittings prevent contaminates from the drain line from flowing back into your water supply and mixing with water that you may use for drinking, showering, or washing dishes. The primary purpose for air gap fittings is to prevent what is called 'back flow'.
Back flow occurs in your drains when you have a blockage in the drain that actually works as a suction mechanism to draw the waste from an appliance like the garbage disposal back into your drainage system. This means that waste that you thought was disposed of will be drawn back into your sink or dishwasher.
For example, if you have a blockage in your pipes due to the fact that you tried to put too much food down your garbage disposal, the discarded material may not have washed out of your drainage system. This situation may cause your water to back up into your sink or dishwasher because it has nowhere else to go. Properly installed air gap fittings will not only prevent this from happening, but will also allow you to use your water until you can call a licensed plumber to figure out what the problem is and have them fix it.
George Salet Plumbers are experts at working with clogged drains and can also recommend the right type of air gap fitting that you can use in your kitchen or even in your laundry room. There are many models to choose from, so it is always wise to talk to your local plumbing professionals for advice about air gap fittings.