how to plumb a 3 compartment restaurant sink

How to Plumb a 3 Compartment Restaurant Sink | DIY 3 Steps

Last Updated on January 28, 2023

Plumbing a three-compartment restaurant sink may seem daunting at first, but it can be a relatively straightforward process with the proper instructions.

This article will provide an in-depth guide on how to plumb a three-compartment restaurant sink, complete with diagrams and expert tips.

So whether you’re a professional contractor or just someone who wants to install a new sink in your home kitchen, read on for all the information you need.

What is a 3 Compartment Restaurant Sink?

What Is A 3 Compartment Restaurant Sink

A 3 compartment sink is just what you think it is: a single sink with three compartments. The main one in the middle holds cold water, while the ones on either side have hot water and clear water.

Three compartment sinks are typically installed in restaurants for washing dishes, cleaning pots and pans, and other general kitchen tasks. They’re also popular in the medical field, where doctors and nurses need to sanitize their hands before examining patients or performing surgery.

Parts of The 3-Compartment Sink

Parts of The 3-Compartment Sink

There are many different types of 3 compartment sinks, but typically they will include the following:

  • An upper spray arm with a swivel nozzle
  • Middle compartment for holding cold water
  • A lower drainboard/shelf where dirty items can be placed to air dry or to soak in soapy water

How to Plumb A 3 Compartment Restaurant Sink: 8 Easy-to-Follow Steps?

How to Plumb A 3 Compartment Restaurant Sink: 8 Easy-to-Follow Steps

For plumbing purposes, you need some tools and supplies before you begin. Here are some things you will need to get the job done right.

Plumbing supplies are needed for installation

  • A 3 compartment sink
  • An extra trap for the middle compartments cold water line
  • An extra-large pipe wrench or channel locks to grip the supply lines tightly (the T-handle type works best)
  • Pipe joint compound and primer for connecting plastic plumbing pipes
  • PTFE thread seal tape

The following list of instructions will guide you on how to plumb a 3 compartment restaurant sink:

1. Plan the Pipe’s Path

In order to plan the path of the cold water pipe, you need to shut off the main water valve. Now is a good time to turn on your garbage disposal so if there’s a leak, it doesn’t flood your kitchen or basement.

2. Trace and Drill

Drill a 1/2″ hole in the cabinet beneath the sink, just large enough to fit the red drain tube. This will allow you to trace where your main cold water line is coming from, so when it comes time to cut through the wall, all you need to do is shine a flashlight behind and look for the supply line.

3. Cut Through the Wall

Find the cold water supply line and use your pipe wrench or channel locks to turn it off. Now you can cut through the sheetrock in the wall using a reciprocating saw.

4. Make the Connections

Once you cut through the wall, you can thread the cold water supply line through the new T-fitting. Make sure to use plenty of pipe joint compound on all threaded joints and tighten with channel locks or a wrench.

5. Connect the Drain Lines

If your drain lines are galvanized steel, they will have to be replaced. Cut the old lines as close to the threaded fittings as possible, and then attach a new stainless steel line using a pipe joint compound and a pipe wrench.

6. Configure the Sink

Most three-compartment sinks will include special nozzles that can be hooked up to either side of the sink so you can switch between three different spray patterns. First, install the tubing and the spray head to the lower drainboard/shelf. The hot water line will connect to both of them (due to their dual-functionality), and then you can either use a T or Y fitting on the end of your clean water supply lines to attach one or two overhead nozzles.

7. Run the Water

After everything is connected, turn on the main water valve and check for leaks. Once everything looks good, you can use your garbage disposal to flush out any residual dirt or joint compound that may clog your drain lines.

8. Test the Three-Compartment Sink

By using a garden hose, you should fill each section with water to make sure everything is working correctly. You can also run some cold and hot water simultaneously to ensure that both sprayer lines are working correctly. If all goes well, then not only have you just plumbed a three-compartment restaurant sink, but you have also saved yourself a service call to install it.

Why Would You Need One?

Why Would You Need One

A restaurant is a place where a lot of dishes are being washed. This means that a lot of dirty water needs to be disposed of, and the sink’s drainage system will have to accommodate this excess waste. For dishes to come out clean, they need to go into hot, soapy water as soon as you are done rinsing them in the cold water sprayer.

If you have only one sink in your restaurant, then you will need to wash, rinse and sanitize your dishes with a single faucet. This can present several problems for you when it comes time to do the dishes. If you don’t let all of the soap out of the sink, then your words will not come out clean. This is why it’s important to use two separate water sources for washing and rinsing.

A Buying Guide for 3 Compartment Restaurant Sinks

A Buying Guide for 3 Compartment Restaurant Sinks

Before you start shopping for a 3 compartment restaurant sink, you need to know a few things. Here are the essentials you should know before buying one.

Material of Sink

There are different materials of sinks available in the market. You need to buy one which is rust-resistant. Stainless steel is the best choice as it can last longer and be customized as per your requirements.

Drain System

The drain system should be efficient for a better performance of your 3 compartment restaurant sink. Ensure that the drain system is ready to work with high pressure and flow rate.

Sink Legs

The leg of the sink should be adjustable so that it can be moved easily, and it should be fitted properly on the floor for a better looking and convenient look.


The faucets should be compatible to ensure the best performance for a 3 compartment restaurant sink. So make sure the faucets are of good quality, and they should be rust-resistant too for more extended durability.

Spray Feature

The spray feature is essential as it makes your job easier to clean dishes after washing, so choose one with two different spray options, either upper or lower section, which can be adjusted quickly.

Overhead Nozzles

The overhead sprayers must have the efficient feature of a 3 compartment restaurant sink, so choose an efficient one that is easy to use and should have adjustable settings for better performance.

Side Trays/Towel Bars

Side trays are functional while drying dishes and hanging towels, so you should buy a sink that has them for better productivity.


Buy the 3 compartment restaurant sinks with add-ons such as soap dispensers or garbage bins to make your kitchen run more efficiently and quickly.

Tips for Maintaining Your 3 Compartment Restaurant Sink

In order to have a good-looking and efficient 3 compartment restaurant sink, you need to know how to maintain it properly. Here are some tips which you should follow:

  • Never let water sit in the sink for long. Always keep it running. This will help prevent rust from developing.
  • Do not use harsh chemicals while cleaning the sink. This will reduce the life of your three-compartment restaurant sink.
  • Wash your sink correctly after every use.
  • Always follow the maintenance guide that came with your 3 compartment restaurant sink to maintain its efficiency for a more extended period of time.
  • Keep the faucets clean and well-lubricated. This will help with the water flow and prevent corrosion of the taps.
  • Always use a strainer over your sink’s drain to catch food particles before they enter your drainage system. This helps prevent problems like clogged drains and foul odors.


The 3 compartment restaurant sink buying guide will help you make the best decision for your kitchen. The buying process can be challenging if you don’t know what to look out for, but this article should have clarified some of that confusion and made it easier for you. Finally, follow our maintenance tips, so your three-compartment restaurant sink stays in good condition and lasts longer while looking great too.

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