Under-sink shutoff valves, also called fixture shutoffs or stop valves, allow you to turn off the water to your sink (or other fixtures) without having to use your home's main shutoff. These inexpensive little valves rarely get used, but when they do, they sometimes leak. Thankfully, it's simple to replace a leaking shutoff valve with a new part that matches the old one. Multiple different valves are used for home plumbing, so identifying which type of water shutoff valve you have is a good first step in replacing it.
Below, learn nine types of under-sink shutoff valves and their purposes to help you identify the valves in your home when replacing or repairing your plumbing fixtures.
01 of 09
Straight Shutoff Valve
- Best for: Vertical water supply pipes from floors or cabinets
Straight stop valves are typically found when the water supply pipe comes up from below the floor or cabinet. The fixture supply tube connects to the top of the valve in the same line as the supply pipe. The handle of a straight stop is located in the middle of the valve body, between the inlet and outlet ports. These valves are often made of chrome-plated brass for durability and are very affordable at most hardware stores.
02 of 09
Angle Stop Valve
- Best for: Water lines from walls with perpendicular valve outlets and inlets
Angle stop valves are normally used when the water line comes out from the wall and the outlet side of the valve will be perpendicular to the inlet side. The handle of an angle stop valve is parallel to the wall and usually faces the front for easy access. Angle stop valves are typically made of copper or chrome-plated brass and are more durable than CPVC over time. These valves have similar prices to straight shutoff valves.
03 of 09
Three-Way Stop Valve
- Best for: Kitchen sinks with multiple plumbing needs
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. Some are cross-shaped and have the two outlet ports facing in opposite directions, some have outlets in an "L" configuration, and some have outlets in a "Y" configuration. Like straight shutoff valves, three-way stop valves are usually made of durable chrome-plated brass (but tend to cost slightly more).
04 of 09
Compression Shutoff Valve
- Best for: Installing on rigid copper pipes without soldering
Compression stop valves are most commonly used to install a shutoff valve on a rigid copper pipe, but some can also be found for copper, PEX, and CPVC pipes. This type of valve has a brass ring, called a ferrule, and a compression nut that squeezes the ferrule into the pipe connection to make a watertight seal. Compression valves are easy to install with just a pair of pliers or wrenches, and they are considered very reliable. You can also remove them and reuse them. Sometimes it is hard to get the old nut and ferrule off of the pipe; in this case, you can remove them with a compression sleeve puller. Compression valves can be found for low prices at most hardware stores.Continue to 5 of 9 below.
05 of 09
Copper Sweat Stop Valve
- Best for: Soldering directly to rigid copper pipes
A copper sweat valve is designed to be sweated, or soldered to a rigid copper pipe. "Sweat" is a plumber's term for soldering. This requires soldering tools, such as a torch, flux, emery cloth, and solder. Sweat valves are not easily removed once they are installed, because they have to be heated to melt the solder so you can pull the valve off of the pipe. This type of under-sink valve is commonly made of durable chrome-plated brass, and it can be found at most hardware stores for affordable prices.
06 of 09
Iron Pipe Stop
- Best for: Galvanized or brass-threaded pipes
Iron stop valves have a threaded female inlet port with iron-pipe-size threads. This type of valve is commonly found on galvanized or brass-threaded pipes, but it can be adapted to other types of pipes by using a male iron pipe adapter that connects to the pipe and then screws into the shutoff valve.
Iron pipe valves simply screw and unscrew from the end of the pipe. The only tools required are two pliers: one to hold the pipe in place, and the other to tighten the valve. Chrome-plated brass versions are available, which cost significantly less than cast iron stop valves and are more durable over time.
07 of 09
CPVC Shutoff Valve
- Best for: Attaching to CPVC pipes
A CPVC shutoff valve has a CPVC insert that allows you to glue the chrome-plated brass valve onto a CPVC pipe using solvent cement. The solvent glue must be designed for this type of pipe to ensure a reliable connection. Once the valve is glued in place, it cannot be removed and must be cut off when repairing a CPVC pipe in the future. Thankfully, installing a new CPVC valve is very affordable, as prices are comparable to other budget-friendly shutoff valves.
08 of 09
PEX Shutoff Valve
- Best for: Attaching to PEX plumbing tubes
PEX shutoff valves used for PEX tubing have a ribbed inlet port for inserting into the tubing. This type of valve works with either ring-type or pinch-type PEX clamps. Although PEX tools are required for installation (as opposed to push-fit valves), these are often the easiest and cheapest way to go, especially if you are already using PEX clamps or pinch rings.
PEX stop valves can be removed, but you have to cut off the ring. This often results in damage to the pipe, which usually means the pipe needs to be shorted to get a fresh section of pipe for the new valve. These valves are typically made of brass or chrome-plated brass and can be replaced on a low budget.Continue to 9 of 9 below.
09 of 09
Push-Fit Shutoff Valve
- Best for: Easy installation with copper, PEX, or CPVC plumbing pipes
Push-fit, or push-in, shutoff valves are very easy to install and can be used with copper, PEX, and CPVC pipe. These brass or chrome-plated brass valves simply push onto the pipe. The valve grips onto the pipe with metal teeth and creates a watertight seal with a plastic O-ring. They are also removable, using a simple tool sold by the manufacturer, and have similar prices to other shutoff valves.
Choosing an Under-Sink Shutoff Valve
When determining which type of under-sink shutoff valve you need, first determine which pipes the valve will connect to. For example, a vertical water pipe from the floor or cabinet should be used with a straight shutoff valve, while angled and three-way stop valves are typically used with perpendicular or multi-pipe plumbing needs.
It's also important to consider the type of plumbing pipes that your valve will shut off. Various valves are available for copper, PEX, and CPVC pipes, and the correct option should be chosen based on the pipe material. If you're unsure which type of shut-off valve you need, consult a plumber for help. You can also turn off your home's main water supply, remove the current valve, and bring it to your local hardware store for a professional to help you find a suitable replacement.
What is the most common valve under the kitchen sink?
An angle stop valve or compression valve is the most common valve under the kitchen sink. If the home is fitted with a dishwasher and connected to the sink line, the valve is likely a three-way stop valve.
Why are there multiple water valves under the kitchen sink?
One pipe (and its valve) brings hot water to the faucet, and a second pipe delivers cold water. If you have a third valve, it might indicate that you have an electric water heater stored under your sink, heating water at the source and connecting back to the faucet.
Is the hot water valve on the left side or right?
In the U.S., the hot water line is on the left side, while the cold water line and its fittings are on the right.
Lead in Drinking Water. Centers for Disease Control and Prevention.