plumbing terms

Key Plumbing Terms Every Homeowner Should Know

Owning a home comes with countless responsibilities, and one of the most fundamental tasks is mastering your plumbing. Plumbing issues can range from minor annoyances to major disasters, but having a basic knowledge of plumbing terms can empower you to tackle them more effectively. Dive into this glossary to familiarize yourself with basic plumbing terms, making it easier to talk with professionals and handle minor repairs independently.

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Section 1: Plumbing Terms on Basic Components

Understanding basic plumbing terms is important for anyone tackling home maintenance or repairs. Familiarity with these terms helps you communicate effectively with plumbers, make informed decisions, and grasp the workings of your home’s plumbing system. This guide will introduce key plumbing components, from pipes and fittings to valves and traps, providing you with the foundational knowledge needed to manage and troubleshoot common plumbing issues confidently.

Angle Stop

Install a vital shut-off valve between the water supply line and a plumbing fixture, such as a sink or toilet. It controls water flow, allowing you to shut off the supply to a specific fixture for repairs or maintenance without affecting the rest of the building’s water system.


A ballcock is a valve controlling water flow into the toilet tank in toilets. It operates through a float mechanism that rises and falls with the water level, opening and closing the valve as needed.

Backwater Valve

The backwater valve plays a necessary plumbing device to prevent sewage from reentering a home. Allowing wastewater to flow out of the house while blocking backflow protects against potential flooding and contamination. This device is significant in areas prone to heavy rainfall or flooding, as it can safeguard basements and lower floors from sewage backup, which can cause substantial damage and health hazards.


In plumbing terminology, a branch, a lateral line, is any secondary part of the drain system. These branches extend from the main drain line, directing wastewater from various fixtures, such as sinks, toilets, and showers, into the primary drainage system.


A flexible membrane is key to regulating water flow and pressure within a valve in plumbing. This component responds to changes in water pressure, expanding and contracting to control the passage of water through the valve.

Flapper Valve

This component acts as a link between the water tank and the toilet bowl. Its primary role is to regulate water flow during the flushing process. When triggered, the flapper valve opens, letting water stored in the tank rush into the bowl, initiating the flushing action. The flapper valve closes once the flushing cycle is complete, preventing further water from entering the bowl.

Knockout Plug

This plumbing term refers to a removable plug-in fixture or appliance that allows for optional connections. Removing a knockout plug creates an opening for pipe connections.


A P-trap is a U-shaped pipe section under sinks, similar to a drain trap. It blocks sewer gases by holding water and catching small objects that might fall into the drain.

Section 2: General Plumbing Terms

Air Gap

An air gap is a vertical space between a water outlet and a fixture’s highest possible water level. It prevents backflow contamination, ensures water flows only in the intended direction, and secures clean and safe drinking water.


Backflow occurs when water flows backward through a plumbing system, potentially contaminating the clean water supply. Preventive devices like backflow preventers are necessary to safeguard against this issue.


Cross-connection is a point in a plumbing system where potable (drinkable) and non-potable water can mix. To prevent contamination, appropriate installation and maintenance of plumbing fixtures are necessary.

Fall or Flow

In plumbing terminology, “fall” or “flow,” often interchangeably referred to as “pitch,” denotes the necessary slope required in pipes to guarantee efficient drainage. This slope facilitates the movement of wastewater and prevents stagnant water or blockages within the plumbing system.

Proper fall is vital for gravity-based drainage systems, such as those found in residential and commercial buildings, to carry wastewater away from fixtures effectively and toward the sewer or septic system. The degree of fall needed depends on pipe diameter, material, and the volume of sewage transported.

Flow Rate

The flow rate measures the volume of water that flows through a pipe or fixture in a given amount of time, usually expressed in gallons per minute (GPM). Understanding flow rates is important for water conservation and system efficiency.

Gray Water

This plumbing term refers to wastewater from common household fixtures such as sinks, showers, baths, and washing machines, excluding toilet waste. You can reuse this relatively clean water for non-potable purposes such as irrigation, flushing toilets, or laundry, reducing overall water consumption and promoting sustainable practices.

Jet Pump

A jet pump draws water from wells or other sources. It creates suction through a jet of water, making it suitable for shallow or deep well applications.

Lateral Line

In plumbing and irrigation systems, a lateral line serves as a secondary pipe branching off the main line, facilitating water distribution to different fixtures or areas.

This component provides efficient water delivery to specific locations within a building or landscape, such as sinks, showers, or irrigation zones. By connecting to the main supply line, lateral lines play a vital role in directing water flow precisely where it’s needed, optimizing the functionality of the overall plumbing or irrigation system.

Section 3: Common Plumbing Terms Associated with Tools


An auger, often called a plumber’s snake, is a basic tool for clearing clogs in pipes. This tool features a long, flexible metal coil to be inserted into drains, breaking up and clearing blockages. Augers come in various types, including manual, electric, and drill-powered versions, catering to different needs and levels of blockage severity.

Basin Wrench

This specialized wrench works in tight spaces, particularly under sinks. Its long handle and swiveling jaw make it ideal for loosening or tightening nuts on faucet connections.

Compression Fitting

This type of fitting connects two pipes or a pipe to a fixture. It creates a watertight seal by compressing a metal ring (ferrule) around the pipe.


It is a versatile handheld tool equipped with a fine-toothed blade. Additionally, it cuts pipes and other materials in plumbing and construction projects. Its compact design and sharp blade allow for precise and controlled cutting, making it indispensable for plumbers.


It is a method of cleaning pipes using high-pressure water streams. Hydro-jetting removes stubborn clogs and buildup in sewer lines and drains.

Joint Compound

Also known as pipe dope, joint compound is a sealant used on threaded pipe connections to ensure a watertight seal. It helps prevent leaks at joints and fittings.

Sump Pump

A sump pump is installed in basements or crawl spaces to remove accumulated water and prevent flooding. It automatically activates when water reaches a certain level.

Section 4: Emergency Plumbing Terms

Pipe Repair Clamp

This clamp quickly and temporarily addresses burst or leaking pipes until permanent repairs are conducted. Its design ensures a secure and watertight seal around the damaged section of the pipe, helping to contain leaks and prevent further water damage.

Pressure Reducing Valve (PRV)

It is a specialized valve installed directly on the main water line to regulate the incoming water pressure from the municipal supply. By constraining the water flow, the PRV reduces the pressure to a safe and consistent level suitable for home use. This crucial component protects plumbing fixtures, appliances, and pipelines from potential damage caused by excessive water pressure, such as leaks, bursts, or premature wear.

Shut-off Valve

It is important in plumbing systems to control water flow to a specific fixture or appliance. These valves enable homeowners to isolate and stop the water supply to individual areas of their property, facilitating maintenance, repairs, or emergencies.

Sewer Backup

This plumbing term describes sewage flowing back into a building through drains or toilets due to blockages or system malfunctions. Such events pose significant health risks and can cause extensive property damage. Tree roots, debris buildup, or collapsed pipes often block the sewer line, leading to these backups.

Now armed with your newfound plumbing knowledge, you’re ready to tackle any problems that crop up with your plumbing like a professional! The next time you encounter a leaky faucet or a clogged drain, you can communicate your concerns effectively when contacting the experts for assistance. And when you’re seeking top-notch service, look no further than Murrieta Plumbing – your go-to, trusted plumbing service provider. With our expertise and loyalty, you can rest assured that your plumbing concerns will be resolved swiftly and effectively.

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