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Plumbing Glossary: Homeowner's Guide to Plumbing Terms

Updated: Feb 13

Whether you're considering plumbing repairs or replacements, it's crucial to have a good grasp of the specialized plumbing terminology used in the plumbing industry. At Refined Home Services, our mission is to empower our clients with knowledge, so we've put together this comprehensive plumbing glossary to assist you in navigating the plumbing world. This list of commonly used plumbing terms will improve communication with professional plumbers.

Plumbing Terms New Hampshire
Commonly used plumbing terms to improve your communication with plumbers.

About this Plumbing Glossary

This plumbing glossary provides a general overview of plumbing terminology and is not exhaustive. The plumbing industry is diverse, and terms may differ by region or practice. While we've aimed to cover a wide range of terms, regional variations or specialized jargon may not be included. We recommend consulting local plumbing experts for precise terminology. This glossary offers a fundamental understanding of plumbing concepts to help you make informed decisions about your plumbing requirements.

Access Panel: An opening in a wall near a fixture, like a toilet, providing access to work on plumbing or electrical systems.

Angle Stop: A shutoff valve between the water supply and plumbing fixture is used to shut off water flow during repairs.

Anode Rod: Located inside the water heater, it protects the water tank from corrosion due to magnesium or aluminum.

Backflow: Reverse flow risking contamination. Backflow preventers safeguard potable water.

Backwater Valve: Prevents disposed sewage from reentering the home.

Ball Check Valve: A type of backflow preventer placed on a water line to direct water flow in one direction.

Circuit Vent: Secondary vent pipe preventing traps from siphoning. Ensures proper drainage in complex plumbing systems.

Check Valve: The valve allows fluid flow in one direction. Used to prevent backflow.

Cleanout Plug: Located in a trap or drain pipe, it offers access to the drain line for clearing blockages.

Closet Auger: A flexible rod used to access a toilet’s trap and remove clogs.

Closet Bend: Connects the closet flange to the toilet drain.

Closet Flange: A ring that anchors the closet, bends to the floor, and secures the toilet in place.

Diaphragm: A flexible membrane regulating water flow and build-up within a valve.

Dielectric Union: Fitting preventing corrosion between metals. Used when connecting pipes of different materials.

Dip Tube: Sends cold water to the bottom of the water heater tank.

Drip Leg: Also known as the “sediment trap,” collects condensation and debris in a lower segment of a gas line.

Drain Cleaning: Removing obstructions, buildup, or clogs from drains and pipes to restore proper flow and drainage. This can involve various methods and tools, such as snaking devices, drain augers, hydro-jetting, or chemical cleaners. Drain cleaning helps to prevent backups, water damage, foul odors, and other plumbing issues by keeping the drainage system clear and functioning effectively. It is an essential maintenance task to ensure the proper operation of sinks, showers, toilets, and other plumbing fixtures in residential, commercial, and industrial settings.

Drain Snake: Flexible wire coiled to clear clogs. Augers and snakes come in various sizes for different drain types.

Escutcheon: A protective cover under the faucet handle that masks the fixture's hole.

Expansion Tank: Tank accommodating water expansion. Critical in closed plumbing systems to prevent pressure buildup.

Fall/Flow: Refers to the slope needed to create proper drainage in pipes.

Faucet: A device controlling the flow of water from pipes in your kitchen sink or bathroom tub. There are different types:

  • Ball Faucets: Common in kitchens, identified by a single handle moving over a rounded ball-shaped cap. It's ideal for those with grip issues.

  • Ceramic Disc Faucets: Modern and reliable, recognizable by a single lever over a wide cylindrical body. High-quality but more expensive.

  • Double-handle Cartridge Faucets: Smooth and consistent action, great for utility sinks, found in older homes.

  • Compression Washers: Common in older homes and utility sinks. It is the least expensive but prone to leaks; replacement parts are inexpensive.

Fixture: A plumbing device providing water and/or disposal, such as toilets, sinks, and showers.

Flapper Valve: Connects the water tank and toilet bowl, controlling water flow.

Float Ball: A plastic ball attached to the ballcock, determining water levels in the tank.

Floor Flange: Connects a toilet to the sewer line; also known as a closet flange.

Frozen Pipe: Repairing frozen pipes in plumbing typically involves thawing the pipes to restore water flow and prevent further damage.

Gas Cock: On a main gas line, allows shutting off the gas.

Gas Pipe: A gas pipe is a conduit or tubing system designed to transport natural gas or other gases from one location to another. These pipes are typically made of materials such as steel, copper, or plastic, depending on the application and the specific requirements of the gas being transported. Gas pipes are an essential part of the infrastructure for delivering natural gas to homes, businesses, and industrial facilities for heating, cooking, and other purposes. They are often buried underground or run along buildings and structures, and they are regulated by safety standards and codes to ensure the proper handling and distribution of gas.

Gate Valve: Controls the flow of liquids in pipes.

Gravity Operated Toilet: Relies on the downward pressure of water in a toilet tank to flush.

Gray Water: Waste water from common fixtures, excluding toilets.

Horizontal Branch: Runs from plumbing fixtures to a waste stack.

Horizontal Run: The distance liquid travels from the entry point to the exit of a pipe.

Hose Bibb: Outdoor faucet connected to a flexible hose. Anti-siphon hose bibbs prevent backflow.

Leak: Unintentional escape of water. Types include:

  • Slab Leaks: Beneath concrete slabs.

  • Pinhole Leaks: Small, often in copper pipes.

  • Faucet Leaks: Common around handles or spouts.

Overflow Pipe: Pipe preventing flooding. Common in toilets and bathtubs, allowing excess water to escape.

Pipe: A tubular conduit for water or gas transportation. Materials vary:

  • Copper Pipes: Durable and corrosion-resistant.

  • PVC Pipes: Lightweight and cost-effective.

  • PEX Pipes: Flexible and easy to install.

Pipe Failure: Numerous factors contribute to pipe failure, including hard water, elevated water pressure, inadequate installation, and poor grounding. These issues can manifest over years of use. Additionally, materials in soil or concrete may react with copper pipes, gradually causing corrosion. Typically, older pipes are more susceptible to corrosion, mainly if they are corroded.

Pipe Issues: Homeowners should be attentive to several indicators that could signal the need for pipe repairs, including:

  • Detection of water leaks along the pipe

  • The presence of corrosion (manifested as white or green build-up) around pipe connections

  • Excessive water pressure experienced in the shower or from faucets

  • Audible signs such as banging or other noises emanating from the pipes or water-utilizing appliances are also known as water hammering.

Pipe Insulation: Material preventing heat loss or freezing. Important in colder climates to prevent burst pipes.

Plunger: Tool for clearing drain clogs. Types include:

  • Cup Plungers: For flat surfaces.

  • Flange Plungers: For toilets.

  • Shut-off Valve: Valve controlling water flow. Types include:

  • Ball Valves: Reliable and durable.

  • Gate Valves: Simple design for on/off control.

  • Globe Valves: Precise control with a globe-shaped disc.

Pressure Regulator: Device controlling and maintaining water pressure. Essential for preventing damage to plumbing fixtures.

P-trap: U-shaped trap under sinks. Ensures a water seal to prevent sewer gas from entering the home.

Rim Holes: Small holes around the toilet bowl, allowing water to wash over the surface.

Saddle Valve: A mounted pipe run by a clamping device, used for quick connections between low-demand devices.

Septic Tank: Underground tank treating sewage. Regular pumping and maintenance are essential.

Sewer Line: Sewer lines are underground pipes or conduits that carry wastewater from homes, buildings, and other facilities to a wastewater treatment plant or a septic tank for processing and disposal. These pipes transport various types of wastewater, including human waste, bathwater, kitchen sink water, and other forms of liquid waste, away from the property to prevent contamination and maintain sanitation. Sewer lines are a crucial component of a community's infrastructure, ensuring proper disposal of wastewater to protect public health and the environment.

Sink: A basin with a drain for washing. Common types include:

  • Drop-in Sinks: Installed from above and visible above the counter.

  • Undermount Sinks: Installed beneath the counter for a seamless look.

  • Pedestal Sinks: Stand-alone, ideal for smaller spaces.

Straight Stop Valve: A straight shutoff valve used to close off water supply during repairs.

Sump Pump: A pump removes accumulated water in basements or crawl spaces. Prevents flooding; primary and battery-operated backup pumps available.

Supply Line: A metal or plastic line carrying water from the main line to a plumbing fixture.

T&P Valve (Temperature and Pressure Valve): Used to release excess heat or pressure in a water tank safely.

Tailpiece: A pipe running between a fixture and trap.

Teflon Tape: Thin tape creating a watertight seal. Used on threaded connections to prevent leaks.

Toilet: A fixture for waste disposal. Varieties include:

  • Gravity-fed Toilets: Standard toilets use gravity for flushing.

  • Pressure-assisted Toilets: Enhanced flushing power with compressed air.

  • Dual-flush Toilets: Save water with two flush options.

Trap: U-shaped pipe preventing sewer gas entry. Common under sinks (P-traps) and less frequently used in other applications (S-traps).

Trapway: Connects the toilet bowl to a waste outlet, influencing clogging.

Trip Lever: The flush handle and actuating arm on a toilet tank; also refers to the drain in a tub.

Vent: A pipe allowing air into the drain system.

Vent Stack: Also known as a stink pipe, it releases gas and odors outside the home.

Water Hammer: A loud noise and vibration associated with pipes being turned on or off, caused by a sudden surge or halt of water in the pipes.

Water Heater: Device heating water for domestic use. Types include:

  • Tankless Water Heaters: On-demand and space-saving.

  • Storage Tank Water Heaters: Traditional with a tank.

  • Heat Pump Water Heaters: Energy-efficient.

Water Meter: Device measuring water consumption. Helps identify leaks and manage water bills.

Water Pressure: The force with which water is delivered. Measured in pounds per square inch (PSI). Proper pressure ensures efficient water usage.

Water Softener: A water softener is a device that removes minerals like calcium and magnesium from hard water, preventing limescale buildup and improving water quality.

Well Pump: A device employed to draw water from a well, available in different types such as submersible pumps, installed underwater, and jet pumps located above ground.

Familiarizing yourself with these plumbing terms will make you better equipped to make informed decisions about your plumbing's maintenance and any necessary repairs or replacements. If you have any questions or require plumbing services, don't hesitate to contact Refined Home Services. We're here to assist you in ensuring the longevity and performance of your plumbing system.


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