Kitchen Sink Anatomy: How Kitchen Sink Plumbing Works (2023)

For some, understanding the anatomy of kitchen sinks is like understanding what's going on under the hood of your car - as long as it works, you don't have to know! But what happens when water is spilling out from behind your kitchen sink cabinet and you don't know what to do next?

Knowing how kitchen sink installation works when problems arise can help you determine if you need to call a plumber or if you can do the job yourself. The great thing about kitchen sink anatomy is that it encompasses many of the basics of plumbing, with many well-designed parts that make it easy to waste and drain water off your property with minimal effort.

This blog unpacks some of the parts that make up the anatomy of the kitchen sink and dives into some helpful tips that can save you time and money later on.

How does the installation of kitchen sinks work?

Upon closer inspection, kitchen sink cabinet doors hide a series of pipes and plumbing parts that work together to support everyday functions. This may seem quite complicated at first glance, so let's go into the details of the inner workings behind kitchen cabinets.

(Video) Anatomy of a Kitchen Drain

First of all, it should be noted that there is a hot and cold water tap and after cleaning there is gray water (waste) that needs to be disposed of efficiently. Additionally, when food particles accumulate, they inevitably cause a clog in the anatomy of your kitchen sink. From the outlets to the pipes, there is a delicate kitchen sink anatomy that keeps the kitchen space working efficiently. Sometimes homeowners canFaucet repair neededwithout knowing it. Read on to learn more about your sink and how it works. So the next time you encounter problems, you can get to the root of the problem.

faucet and aerator

Kitchen Sink Anatomy: How Kitchen Sink Plumbing Works (1)Let's start with the first thing that strikes us about kitchen sinks.- the faucet. Depending on countertop space or aesthetic preferences, this accessory can be attached to the sink itself or to the wall.

But to enjoy better water flow or pressure, you might consider screwing an aerator onto your faucet. This little tool creates a mixture of water and air to make the stream smoother and softer and reduce water splashing in the bowl. It also improves the physical functioning of your faucet, allowing you to reduce the amount of water you use each day.

The filter

Chances are you have a built-in kitchen sink, which means you have a rubber grommet connecting the PVC pipe to the sink drain. It could very well have a filter attached, which is your first line of defense against excess food waste going down the drain.

the trap

Kitchen Sink Anatomy: How Kitchen Sink Plumbing Works (2)The siphon is ingenious in its simplicity when it comes to installing kitchen sinks. The function of the siphon is to prevent the unwanted outflow of liquid or gas fRome enters the house.Also known as a "strap" or "u-bend" depending on the shape, it is basically a segment of pipe that bends back on itself to create a water and air seal and the release of harmful gases back into your kitchen to prevent. through the drain. It's worth noting that in some parts of the US, "straps" are no longer accepted by building codes because they dry out.

(Video) Plumbing Underneath Your Kitchen Sink - Plumbing Tips

An anatomical diagram of the kitchen sink shows how the "trap" works and how gravity and plumbing work together to keep unpleasant odors at bay. The trap is also easy to remove. So if you've ever dropped a tiny item down the sink and panicked that you've lost it forever, this is the first place to look. All heavy items, from jewelry to leftover food, end up here, as well as unsightly debris like hair and sand.

Ideally, you should clean your trap regularly to remove debris. There should be a cleaning area at the bottom of the trap where you can access the pipe. Place a bucket or bowl under this area before trying to do anything or restore items yourself!

the pipes

Kitchen Sink Anatomy: How Kitchen Sink Plumbing Works (3)Which pipes are required for a kitchen sink depends on your needs. If you look at your average kitchen, you want a sink with pipes that admit both hot and cold water. A double sink that allows you to wash dishes in cold water with soap is ideal, but not essential. Whatever you have in your kitchen - be it a dishwasher, washing machine or garbage disposal unit - it all converges under your kitchen sink.

We recommend labeling your water lines (red for hot, blue for cold) so you can easily identify where a leak is coming from and if you need to turn off your water heater if there is a leak. Use colored tape, which you can purchase at your local hardware store.

SeYour tubes were well installed, there should also be switches on each of them to shut off the water supply and isolate leaks so you can tackle any plumbing work required.

(Video) How Your Home Plumbing Works (From Start to Finish) | GOT2LEARN

Avoid overloading too many pipes in a drain system as this can cause clogs and buildup. You should also make sure that your pipes have a reasonable length from the sink to the drain so that the gray water has the space and time to slowly drain away. If you ask the plumber, "What kind of pipes are needed for a kitchen sink?" , ask for "stacking" as a solution to avoid water retention.

Remember that if the pressure in the kitchen sink lines is too high, water will enter so it will find a way out of your plumbing. If you're seeing wet chipboard under your kitchen sink, it's the result of a malfunctioning kitchen sink installation.

the garbage disposal

Since its invention in the 1920's, the garbage disposal unit has become an invaluable part of the kitchen sink installation. It is a small shredder that is usually installed between the sink drain and the siphon and is used to shred all food waste into smaller pieces so that it can pass through the plumbing without clogging the kitchen sink drain.

While there are powerful machines that can shred thick bones or other hard materials, remember that not all leftover food and liquids belong in the trash. You can avoid serious plumbing problems by avoiding stringy food, grease and oil.

If you have a garbage disposal problem, it's best to have your device repaired right away. So, of course, remember that you have a part to play too: avoid tossing nuisance waste in your disposal unit and take it to the actual bin instead.

(Video) How to Plumb a Drain - Sink Drain Pipes

shut-off valve

Kitchen Sink Anatomy: How Kitchen Sink Plumbing Works (4)A shut-off valve, sometimes called a shut-off valve, is a device you may find under your kitchen sink and is often built into your plumbing. The main purpose of this device is to shut off the water supply to your sink faucet (or other appliances in your home such as a toilet, dishwasher or water heater) without having to use the main shut off valve.

This control becomes a useful feature, especially at times when you need to fix the pipes in the kitchen sink. The shut-off valve prevents water from flowing into the faucet, allowing your plumbing professionals to fix a crack or leak in your plumbing system with little effort.

Connections to other devices

Kitchen Sink Anatomy: How Kitchen Sink Plumbing Works (5)Modern kitchens may have more than just a dishwasher hookup as part of their kitchen sink anatomy. A kitchen waste disposer that attaches to the underside of the sink offers the convenience of disposing of leftovers at the touch of a button. Of course, you need to know how the waste unit is cleaned and understand how it relates to your drainage system.

A dishwasher and ice maker are other useful appliances that will likely find space under your kitchen sink together. Whether you're renovating your kitchen or starting from scratch, a kitchen sink installation diagram provided by a reputable plumbing company can help map the arterial network of your kitchen sink installation so you can figure out how your kitchen sink installation will perform and then plan accordingly if you need wall hanging or wall cut piping in your new kitchen.

In this case, it will be useful to understand the intricacies of the plumbing system of your kitchen. It is always advisable to seek professional advice from an experienced plumber.

(Video) How to install the kitchen sink drain pipes

Expert Plumbing with Alliance Service Pros

Alliance Service Professionalsis staffed with professionally trained plumbers who will analyze any situation and provide practical advice on how to set up and maintain kitchen sink installations with a minimum of fuss. If you have trouble installing your kitchen sink,contact us todayand we will be happy to help you with an offer and discuss your options with you.


How does the plumbing to a kitchen sink work? ›

The Basics of Kitchen Sink Plumbing

They usually have two basins draining into a trap that blocks sewer gas from entering the house. A trap arm joins the trap to the drainpipe at the wall. Under a single sink is a one-piece fixed or swivel trap, consisting of a trap connected to a trap arm.

What are the pipes under my kitchen sink? ›

The p-trap under sink plumbing pipe serves the function of capturing a small amount of water inside your drainpipes after the sink is used. This plug prevents sewer gases from coming up the wastewater line and out the sink.

How do kitchen pipes work? ›

When water runs down a sink drain, it moves through the trap and exits out the drainpipe. But because the drainpipe exits at a higher level than the curved portion of the pipe, some water is captured and held in the trap's curve. This water provides a seal, blocking sewer gases from rising up through the sink drain.

What is the sink pipe called? ›

The most noticeable piece of piping in your household plumbing is a section of drainpipe located under your kitchen and bathroom drains. You see this pipe each time you open up the sink cabinet, and it's one of the few pipes in your house that you'll immediately detect leaks from.

What is a sink called in plumbing? ›

Lavatory. While sometimes used by the general public to mean a bathroom or washroom, the plumbing industry uses lavatory to mean a bathroom washbowl or basin permanently installed with running water. The plumbing industry uses the term "sink" in reference to kitchen sinks.

How does a sink valve work? ›

Understanding Valves

The valve lives inside the cartridge housing. It operates via moving the faucet handle from side to side. This motion allows for varying amounts of hot and cold water to flow through the diamond-embedded disc. They enter and combine inside the ceramic dic and then flow out of the faucet.

What are the 3 valves under kitchen sink? ›

Under kitchen sinks, there will typically be three shut off valves. The two uppermost valves will be the hot and cold valves for the sink faucet. The lower valve is for the dishwasher. Conventionally, these valves would connect to the faucet in the same way as bathroom valves/faucets with replaceable supply lines.

What is the p-trap under the sink? ›

A P-trap is a bend in a drain and waste pipe with a specific purpose. That bend in the pipe contains a pocket of water, which blocks toxic, foul-smelling sewer gases (like methane) from traveling through the pipe into your home.

Why is there a vent pipe under my sink? ›

A vent is a necessary part of the drain system for any plumbing fixture. Its purpose is to equalize pressure in the pipes and prevent a vacuum from forming as the fixture drains.

What are the basic plumbing principles? ›

Plumbing follows the basic laws of nature — gravity, pressure and water seeking its own level. Knowing this, you can understand its "mysteries" and make dozens of fixes to your home's plumbing system.

What is the plumbing cycle? ›

Plumbing cycle refers to a mechanism through which water is taken from a source, then supplied to the users, and finally waste water is collected and recycled to the source after proper treatment (Fig. 1.1). Plumbing and pipe-fittings play a major role in the construction of all types of buildings.

How does sink drain pipe work? ›

Drains simply work by using gravity. When you push down the sink plunger, the drain sucks water through the opening into the appliance drain line. As the water falls straight down the vertical appliance line, it gathers speed and velocity. That speed allows it to move past the p-trap and into your home's drainpipes.

Where does the water from the kitchen sink go? ›

When the wastewater flushed from your toilet or drained from your household sinks, washing machine, or dishwasher leaves your home, it flows through your community's sanitary sewer system to a wastewater treatment facility.

What are the 4 types of plumbing? ›

There are five main types of plumbing pipe materials that are still in use today: copper, galvanized steel, polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), and cross-linked polyethylene (PEX).
  • PVC Pipes. ...
  • PEX Pipes. ...
  • ABS Pipes. ...
  • Copper Pipes. ...
  • Cast Iron and Galvanized Steel Pipes.
30 Apr 2021

Why are sink pipes curved? ›

To prevent sewer gasses from entering your living space. The pipe bend known as the trap ensures that there is a water seal separating the sewage system from the inside of your home. Like the rest of the wastewater system, it relies on gravity to keep the water within the bend.

What is kitchen air gap? ›

A dishwasher air gap is a cylinder fitting that connects the kitchen sink drain to your dishwasher, preventing dirty water from flowing into the dishwasher as well as out of it during a wash cycle.

What are sink flanges? ›

What Is a Sink Flange? A sink flange connects the sink drain to a section of pipe called a tailpiece to create a tight seal. It is made of metal and sits around the edge of the drain rather like a collar, and it usually has a grid-like section covering the drain that looks like a strainer.

What are the three types of sink? ›

There are three main types of kitchen sinks: drop-in sinks, undermount sinks and farmhouse sinks.

What are the 3 holes in the sink for? ›

Depending on the design of your sink, it may have one, two or three holes, and they may appear between the faucet valves, facing toward you, or under the near rim, facing the mirror. They serve two functions: to prevent an overflow with the drain stopper engaged and to provide an escape route for air in the drain.

What is the full meaning of sink? ›

sink verb (GO DOWN BELOW)

to (cause something or someone to) go down below the surface or to the bottom of a liquid or soft substance: The Titanic was a passenger ship which sank (to the bottom of the ocean) in 1912. The legs of the garden chair sank into the soft ground.

What is the most common plumbing problem? ›

The most common plumbing problems are clogged drains and toilets, leaky faucets and pipes, water heater issues, low water pressure, and a running toilet. Each of these issues requires a different solution that we will cover below.

What type of valve is a kitchen sink? ›

Three-Way Stop Valve

Three-way stop valves have an inlet and two outlets. These are often seen under kitchen sinks, where they are used to feed both the hot tap of the faucet as well as the dishwasher. Three-way stops can come in a few different configurations.

How do I control the water flow to my kitchen faucet? ›

To adjust the water pressure of your faucet, locate the 2 valves underneath your sink that control hot and cold water. Turn the valves counterclockwise to increase the water pressure or clockwise to decrease it.

What is a sink drain assembly? ›

The pop-up drain assembly connects the sink to the P-trap drain plumbing. The assembly consists of the flange and stopper (also called the pop-up), which are the parts you see in the sink; the drain tube, which is the main body under the sink; and the ball-and-rod assembly, which moves the stopper up and down.

What is the most common method of joining pipes? ›

A butt weld is the most common type of pipe joining welding method. Workers use this method to join two pipes of the same diameter. Generally, these joints are most prevalent in commercial or industrial pipe systems.

How pipes are joined? ›

Pipes are commonly joined by welding, by using pipe threads, or by using a mechanical coupling. Process piping is usually joined by welding using a TIG or MIG process. The most common process pipe joint is the butt weld.

What are the 4 types of fittings? ›

Coupling, Adapter, Bushing and Union Fittings

For example, an adapter could be fitted on the end of a plain pipe to allow a threaded connection at the other side of the adapter. Bushing Fittings - Bushings, sometimes called reducer bushings, are used for connecting two pipes of different sizes.

Which side of the sink is hot water? ›

Cold water should always be on the right side of the faucet and hot on the left. This is an industry standard throughout North America, and applies to single lever as well as dual faucets.

What do you need to connect sink to drain? ›

There are 3 parts you'll need when installing a new sink drain: a P Trap kit, a trap adapter, and a pop-up (or regular) sink drain assembly.

Should sink valves be fully open? ›

Similar to gate valves, ball valves should be all the way open to allow the full flow of water or all the way closed to restrict all water from flowing. The valve is controlled by moving it between 0 and 90 degrees. If the lever is aligned with the pipe, water will flow.

What is 2 way valve and 3 way valve? ›

A 2-way valve is any type of valve with two ports: an inlet and an outlet port, typically labelled A and AB respectively. With two ports, the valve passes the water in one direction only. 3-way valves have three ports, labelled A, B, and AB. With three ports, the 3-way valve passes the water in two directions.

What are the 4 types of valves? ›

Heart Valves, Anatomy and Function
  • tricuspid valve: located between the right atrium and the right ventricle.
  • pulmonary valve: located between the right ventricle and the pulmonary artery.
  • mitral valve: located between the left atrium and the left ventricle.
  • aortic valve: located between the left ventricle and the aorta.

Why is P-trap full of water? ›

They are designed to constantly hold water in the drain to prevent sewer gas from escaping into the house. While sewer gases may contain noxious odors and smell terrible, they can also be explosive and poisonous. Ensuring that your P-trap has enough water will keep things running smoothly.

How do I know if my P-trap is working? ›

Is your P-trap working properly? If you detect any foul odors near the P-trap that remind you of a smell similar to rotten eggs, then it means that there is hydrogen sulfide present. This, and other harmful gases, bacteria, and viruses, can get into the house if your plumbing trap has malfunctioned.

What is the difference between P-trap and S-trap? ›

The difference between the two traps is simple: the shape. An S-trap flows down from the drain, curves up, then curves back down. The P-trap also flows down from the drain and curves, but the curve finishes on a horizontal pipe that takes the waste out.

What happens if a sink drain is not vented? ›

Water in drain traps under sinks and other fixtures prevent sewer gas in the plumbing from entering your home. When drain lines aren't properly vented, low pressure inside the pipe can suck water out of the traps, letting sewer gas in.

What happens if plumbing is not vented properly? ›

Poorly-vented drain lines will not be able to effectively move wastewater and solid waste out of your building. This could lead to problems such as overflowing drains, backed-up toilets, and similar plumbing issues.

What happens if you don't vent a drain? ›

Without a vent to allow pressure to escape from the plumbing system, harmful sewer gases can build up and make it difficult for water to move through the pipes efficiently. A clogged plumbing vent creates problems not because it doesn't allow air in, but because it won't let it out.

Are kitchen sink and toilet pipes connected? ›

What is this? The main drain line is the primary pipe that connects to each of the drains in your household. This includes showers, toilets, and sinks throughout your home. All the wastewater you generate in your home flows into these pipes, eventually ending up in the sewage system.

Where does kitchen sink water go? ›

Where does the water go after you flush the toilet or drain the sinks in your home? When the wastewater flushed from your toilet or drained from your household sinks, washing machine, or dishwasher leaves your home, it flows through your community's sanitary sewer system to a wastewater treatment facility.

What is the 4th hole in sink for? ›

Kitchen Sink Mounting Holes

4-hole sinks allow for a two-handle faucet and a sprayer or soap dispenser. 3-hole sinks allow for two-handle faucets only without accessories. 2-hole sinks allow for a single-hole faucet, and an accessory, like a sprayer.

What is the second hole in the sink called? ›

The overflow hole is aptly named, as it keeps your sink from flooding. It does this by diverting water, giving you more time to act before the contents spill over if you or someone in your household accidentally leaves the faucet on or if you have a plumbing issue.

What are the 2 types of sink hole? ›

Two types of sinkholes exist. One forms when the roof of a cave collapses and exposes the underground cavern. The second type forms when water dissolves the rock underneath soil and creates an underground chasm. Without rock to support it, the soil layer collapses and creates a hole on the surface.

Does bathroom and kitchen water come from the same place? ›

According to Hafren Dyfrdwy Limited (formerly Dee Valley Water Limited), the water in your bathroom taps has usually been stored in a tank in the loft. Hence, unlike the water in your kitchen tap, this water isn't fresh from the mains.

Does sink water and toilet water go to the same place? ›

You see, every drain in your home is connected to a pipe that moves used water from your house to a sewer in the street; that's right, every toilet, shower, sink, washing machine, dishwasher, and anything else that uses water connects to one singular pipe.

Does the kitchen sink drain into the sewer? ›

All sinks drain into the master drain line, which connects to the municipal sewer line or your home's septic system. The food, grease, dirt, and hair that accumulates in your sink pipes will eventually find their way to this main line.

Why do I have 3 shut off valves under kitchen sink? ›

Three-Way Stop Valve

These are often seen under kitchen sinks, where they are used to feed both the hot tap of the faucet as well as the dishwasher.

What is the valve under the sink called? ›

Also known as fixture shut offs or stop valves, under-sink valves allow you to turn off the water to the sink without shutting it off to the whole house. The number and type of fixture shutoffs you choose will depend on how many fixtures there are and where they're located.

Where does sink water end up? ›

In a city, household drains connect to a larger pipe that carries wastewater into the city's underground collection system of sanitary sewers. As wastewater from homes, businesses and industries collects, sanitary sewer pipes get bigger and bigger as they near the wastewater plant.

Why kitchen water is always direct? ›

In contrast to the indirect system, the direct system is cheaper to install, reduces the chance of a bacterial contamination and is more suited to high demand. Obviously, another advantage is the fact it provides safe drinking water to all cold taps in the house.

Where do kitchen pipes lead to? ›

All wastewater from your house is carried to the municipal sewer line by one main drain pipe that typically runs horizontally, but with a slight downward slope, under the lowest floor in your home out to the municipal sewer main or out to the septic field.


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