Plumbing Glossary

Welcome to Smoak’s plumbing glossary page. This page will educate those unfamiliar with the plumbing industry on the terminology and jargon. Understanding the language is crucial for making informed decisions, maintaining your plumbing system, or effectively communicating with experts.

This glossary aims to provide clear and concise explanations of the key terms, concepts, and components related to plumbing helping you navigate the world of home comfort and maintenance with confidence. Whether you’re looking for explanations of some of the most common plumbing terms or diving into more technical aspects of these systems, you’ll find the information you need here.

Please email us if there are any additional terms that we may have missed.

Plumbing Glossary

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The type of plastic material commonly used to manufacture bathtubs and shower enclosures, known for its durability, lightweight nature, and ease of maintenance.

ADA is an acronym that stands for the Americans with Disabilities Act, which sets guidelines and standards for accessible design in plumbing fixtures, ensuring they are usable by individuals with disabilities.

An aerator is a device typically attached to the end of a faucet that mixes air with the flowing water, reducing splashing, conserving water, and improving overall water efficiency.

A flexible tool or cable used to clear clogs from drains and pipes by breaking up and removing obstructions.


A ballcock is a valve mechanism used in toilet tanks to control the filling of the tank with water and shut off the flow once a certain water level is reached.

BTU (British Thermal Units)
BTUs is a unit of measurement used to quantify the heat energy required to raise the temperature of one pound of water by one degree Fahrenheit and is often used to measure the heating capacity of water heaters.


A cleanout is a removable access point or cap within a sewer or drain line that allows for the inspection, cleaning, and clearing of blockages or debris in the pipe.

A closet is slang for a water closet, commonly known as a toilet or commode.

A commode is a common term used to refer to a toilet, which is a fixture for human waste disposal and is connected to a sewage and drainage system.

A coupling is a short, tube-like fitting that connects two pipes together, allowing for the transmission of fluids while maintaining a secure and leak-resistant connection.

CPVC (Chlorinated Polyvinyl Chloride)
A type of plastic piping material used for the distribution of hot and cold water in residential plumbing systems.


Drainage is the process of removing excess water or other liquids from an area, typically through a network of pipes or drains.

A drainpipe is a pipe that carries wastewater from plumbing fixtures to the sewer or septic system. It helps maintain proper sanitation.


Energy Star
ENERGY STAR is a program initiated by the U.S. Environmental Protection Agency (EPA) that identifies and promotes energy-efficient plumbing products to help consumers reduce energy consumption and lower utility costs.

Expansion Valve
An expansion valve is a device that regulates the refrigerant flow into an evaporator coil, controlling the cooling process and reducing the refrigerant’s pressure and temperature, thus enabling efficient heat exchange.


A faucet, also known as a tap, is a device that controls the flow of water from a plumbing system. It is commonly used in sinks, showers, and bathtubs.

Finishes are the visible surface materials and textures applied to plumbing fixtures, such as faucets and showerheads, for aesthetic and functional purposes, including chrome, brass, satin nickel, and white.

A fitting is a component used to connect, join, or adapt pipes, tubes, or other plumbing materials to ensure proper fluid flow and connections within a plumbing system.

A flange is a rim or collar projecting from pipes, fixtures, or toilet bowls, employed to secure and connect them to surfaces such as floors and walls within a plumbing system.

Flow Volume
The flow volume represents the quantity of water that passes through a pipe, fixture, or faucet within a specified duration, commonly assessed in terms of gallons per minute (GPM) or liters per minute (LPM).

Flush Capacity (GPF)
Flush capacity, often referred to as Gallons Per Flush (GPF), is a metric that quantifies the amount of water a toilet expels with each flush, serving as an indicator of its water efficiency.


Garbage Disposal
An electric appliance, commonly integrated into a kitchen sink drain, dedicated to grinding and pulverizing food waste, facilitating its removal along with water, thereby reducing the volume of solid waste directed to landfills.

Gas Cock or Gas Valve
A gas cock, a vital component within a piping system, operates as a valve or shutoff mechanism responsible for regulating the flow of natural gas or propane. It is frequently used in conjunction with appliances like gas stoves and water heaters.

A flat, typically rubber or silicone sealing ring used to create a watertight connection between two plumbing components, such as between pipe sections or between a toilet tank and bowl.


Hard Water
Hard water is water that contains a high concentration of minerals, primarily calcium and magnesium ions that can lead to scale buildup in pipes, fixtures, and appliances.

Hose Bib
A hose bib is an outdoor faucet or spigot connected to a water supply, designed for attaching hoses and other watering devices for outdoor use, such as gardening or car washing.


A leak is an unintentional escape of water or gas from a pipe, fixture, or appliance. Leaks can cause damage and waste valuable resources.


Main Line
The main line refers to the primary sewer or water line that connects a building to the municipal or private utility system, serving as the central conduit for wastewater or freshwater distribution throughout the property.


PEX stands for cross-linked polyethylene, a flexible and durable type of plastic pipe used for water supply and radiant heating systems, known for its resistance to corrosion and ease of installation.

Pilot Light
A pilot light is a small, continuously burning flame in gas-fueled appliances, such as water heaters and furnaces, used to ignite the main burner and maintain a heat source for the appliance to function as needed.

A pipe is a tubular structure typically made of metal, plastic, or other materials that carries fluids, such as water or gas, within a plumbing system.

Piping is the network or system of pipes, tubing, and fittings used to convey liquids, gases, or solids within a plumbing or fluid transport system.

Plumbing Fixture
A plumbing fixture is a device or appliance such as a sink, toilet, shower, or faucet, designed for a specific function in a building’s plumbing system.

Plumber’s Putty
Plumber’s putty is a soft, malleable, and waterproof sealant used to create a watertight seal between surfaces of a plumbing fixture, like a sink or drain, and the connecting components, preventing water leakage.

PVC or polyvinyl chloride is a type of rigid plastic pipe are commonly used for drain, waste, and vent (DWV) systems, as well as for some water supply lines in residential plumbing.

A plunger is a tool used to clear clogged drains or toilets by creating pressure and dislodging blockages.


Sediment is the solid particles or debris, such as minerals, rust, or sand, that can accumulate in water supply lines or plumbing fixtures, potentially causing clogs or reduced water flow.

Shut-off Valve
A shut-off valve is the type of valve or faucet used to control or completely stop the flow of water or gas in a plumbing system, allowing for maintenance, repair, or isolation of specific areas.

A plumbing snake is flexible and coiled tool, also known as a drain auger or plumber’s snake, used to clear clogs or blockages from drains, pipes, or sewer lines by manually rotating and feeding it through the plumbing system.

Sump Pump
Sump pumps are a mechanical device installed in a basement or crawl space to remove excess groundwater or accumulated water, preventing flooding and water damage to the building’s foundation.


Tankless Water Heater
Tankless water heaters are a type of water heating system that heats water on demand without the need for a storage tank, providing hot water continuously and with increased energy efficiency.

A trap is a U-shaped pipe or fitting installed beneath sinks, drains, or toilets to prevent sewer gases from entering a building while allowing wastewater to flow through.


A vent is a vertical or sloping pipe or fitting that connects to a drain line to allow air to enter the plumbing system, equalizing pressure, preventing siphoning, and ensuring proper drainage and wastewater flow.


Water Heater
A water heater is a device that heats water for domestic use, such as bathing, cleaning, sanitizing, and cooking. Types include tankless, tank-style, gas, and electric water heaters.

Water Hammer
A water hammer refers to the sudden and forceful shockwave or noise in a plumbing system caused by the abrupt stop or change in the flow of water, typically resulting from quickly closing a valve or faucet, which can potentially damage pipes and fittings.

Water Key
A water key is a long-handled tool designed to open and close water valves located underground, typically used by utility workers and plumbers to control the flow of water in municipal water systems.

Water Pressure
Water pressure refers to the force or energy at which water is pushed through pipes and fixtures in a plumbing system, typically measured in PSI (pounds per square inch) or bars, influencing the flow and performance of water-related appliances.