Glossary 2
Sigma Faucet Parts Β· Reference Guide
Plumbing & Faucet Glossary
Understand the terminology behind faucets, shower valves, cartridges, and plumbing components. Find clear explanations of the parts and products used in quality plumbing installations.
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All glossary terms
Alphabetical reference
A
- Aerator
- A small device screwed into the tip of a faucet spout that mixes air with the water stream. This creates a smooth, splash-free flow while reducing water consumption and increasing perceived pressure.
- Anti-Scald
- A safety feature or valve type that prevents water temperature from exceeding a safe level (typically limited to 120Β°F), protecting users from burns caused by sudden pressure or temperature changes.
- Assembly
- A complete or pre-assembled collection of components that function together as a unit, such as a valve assembly, trim assembly, or cartridge assembly.
B
- Body Spray
- Small, directional water jets mounted on the shower wall that spray water from the sides for a massage-like or full-body rinse experience.
- Brass
- A durable copper-zinc alloy widely used in premium faucet bodies, valves, and fittings for its strength, corrosion resistance, and ability to hold fine finishes.
C
- Cartridge
- The replaceable internal valve mechanism inside a faucet or shower valve that controls water flow and the mixing of hot and cold water. Common types include ceramic disc, pressure-balancing, and thermostatic cartridges.
- Centerset
- A faucet configuration in which the handles and spout are mounted on a single base plate, typically spaced 4 inches apart center-to-center.
- Ceramic Disc
- A modern cartridge design using two hard ceramic discs that slide against each other to open, close, and regulate water flow. Known for smooth operation, durability, and leak resistance.
- Check Valve
- A one-way valve that allows water to flow in only one direction, preventing backflow that could contaminate the potable water supply.
D
- Deck-Mounted
- A faucet or fixture installed on the horizontal surface of a sink deck, countertop, or bathtub rim rather than on a vertical wall.
- Diverter
- A valve or mechanism that redirects water flow from one outlet to another, such as from a tub spout to a showerhead or between multiple shower outlets.
E
- Escutcheon
- A decorative plate or flange that covers the mounting hole or wall opening where a faucet handle, spout, or shower trim meets the surface, providing a finished appearance and helping seal against water.
F
- Finish
- The decorative surface treatment applied to a fixture for appearance and protection. Common luxury finishes include polished chrome, brushed nickel, polished nickel, oil-rubbed bronze, and matte black.
- Flow Rate
- The volume of water delivered by a faucet or showerhead, typically measured in gallons per minute (GPM). Lower flow rates help conserve water while still providing a satisfying experience.
- Flange
- A flat rim or projecting edge used for mounting or covering the base of a fixture, often serving a similar purpose to an escutcheon.
G
- GPM
- Gallons Per Minute β the standard unit used to measure the water flow rate of faucets and showerheads.
H
- Handle
- The control lever, knob, or cross handle used to operate a faucet or shower valve, adjusting water flow and/or temperature.
- Handheld Shower
- A detachable showerhead connected to a flexible hose, allowing the user to direct water precisely for rinsing or targeted cleaning. Also called a handshower.
I
- In-Wall
- Components or valves installed inside the wall cavity (behind the finished surface), as opposed to exposed or deck-mounted fixtures.
L
- Lever Handle
- A flat, elongated handle design that is easy to operate with the wrist or elbow, favored in modern and accessible luxury fixtures.
- Lubricant
- Silicone-based plumber's grease (also called silicone lubricant) used on O-rings, cartridges, and valve stems. It reduces friction, helps create a watertight seal, protects rubber from drying out, and makes parts easier to install or remove. Petroleum-based greases should be avoided because they can degrade rubber seals.
M
- MIP
- Male Iron Pipe β a male-threaded pipe fitting connection commonly used on valves and fittings.
- Mixing Valve
- A valve that blends hot and cold water supplies to deliver water at a desired temperature. Includes pressure-balancing and thermostatic types.
N
- NPT
- National Pipe Thread β the U.S. standard for tapered pipe threads used on fittings such as MIP connections. The taper creates a seal as the threads are tightened.
O
- Γ (Outside Diameter)
- Symbol for Outside Diameter, used to specify the external measurement of pipes, tubes, or fittings.
- O-Ring
- A circular elastomeric seal used in valves, cartridges, and fittings to prevent water leaks at connection points and moving parts.
P
- Pressure-Balancing Valve
- A shower valve that maintains a consistent water temperature by automatically adjusting the mix of hot and cold water when pressure changes occur in either supply line (for example, when a toilet is flushed). Also known as a Type P valve.
- Pull-Down
- A faucet spout that can be pulled downward from its resting position for extended reach, often incorporating a spray function.
R
- Rain Shower
- A large overhead showerhead that delivers a soft, wide, rain-like cascade of water for a spa-like experience.
- Rough Valve / Rough-in Valve
- The plumbing valve body installed in the wall during the rough-in stage of construction (before walls are finished). The decorative trim is later attached to this valve. Rough-in valves are typically brand-specific and must match the trim.
- Rough-in
- The construction stage during which the pipes, valve bodies, and other plumbing infrastructure are installed and tested before the walls and finishes are completed.
S
- Showerhead
- The fixture that disperses water in a shower. Available in fixed overhead, handheld, rain, and multi-function styles.
- Single-Hole
- A faucet that mounts through a single hole in the sink or deck, typically with an integrated handle or lever.
- Spout
- The outlet portion of a faucet from which water flows into the sink or tub.
T
- Thermostatic Valve
- A shower or tub valve that maintains a precise, user-set water temperature by sensing the actual mixed-water temperature and automatically adjusting the hot/cold ratio. Preferred in luxury installations for superior comfort, safety, and the ability to support multiple outlets. Also known as a Type T valve. Often used with a separate volume control.
- Trim
- The decorative and functional exterior components of a faucet or shower (handles, escutcheons, spouts, showerheads, etc.) that are installed after the rough-in plumbing is complete. Trim kits are usually brand- and valve-specific.
- Tub Spout
- The outlet that fills a bathtub. Many include an integrated diverter to redirect water to a showerhead.
V
- Valve
- The mechanism that controls the start, stop, and mixing of water flow. In showers, this typically refers to the rough-in valve body and its cartridge.
- Volume Control
- A separate control (often a second handle) that regulates the amount of water flow independently of temperature. Common on thermostatic shower systems.
W
- Wall-Mounted
- A faucet or shower fixture that is installed directly onto a vertical wall surface rather than on a deck or countertop.
- Widespread
- A faucet style with separate handles and spout that are mounted independently, typically with 8-inch centers, offering greater design flexibility.
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