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Plumbing & Hardware Glossary




California Assembly Bill 1953 (AB1953) was originally signed into law September, 2006. This legislation required a reduction in the lead content of products to a weighted average lead content of no more than 0.25% in pipes, fixtures and fittings. This includes kitchen faucets, bathroom faucets, and any other end-use devices intended to convey or dispense water for human consumption through drinking or cooking. In the new legislation, starting in 2010, only plumbing products and piping used to convey drinking water that meet this criterion can be sold in California.

AB1953 does not replace NSF/ANSI 61. AB1953 specifically addresses the lead content used in the manufacturing of the products, while the NSF/ANSI 61 is a performance standard that measures the amount of lead and other metals that may leach in the water at the point-of-use.

Plastic used in the manufacture of drain, waste and vent pipes.

A glassy, thermoplastic material that is cast and molded into shapes. A common material for bathtubs, whirlpools and shower bases, acrylic has a naturally glossy finish and is lightweight.

Adjustable backset:
Mechanism that allows adjusting to fit the distance from the door's edge to the center of the knob on pre-drilled doors.

A small device at the end of a faucet spout that mixes air into the flowing water.

Angle stop:
A shutoff valve between water pipes and a faucet or toilet. The inlet connects to the water supply pipe in a wall, the outlet angles up 90 degrees to the faucet.

Device that prevents water from flowing back into supply lines, possibly contaminating the water supply.

When water traveling from one device backs into any part of the main water supply, usually caused by siphoning.

Backflow preventer:
A device used to prevent backflow. In some areas, plumbing codes require a backflow preventer.

An escutcheon, typically larger than a rosette, on which a knob or pull sits.

The distance from the edge of the door to the center of the drilled knob or deadbolt hole. 2-3/8" is the most common backset, followed by a 2-3/4" backset.

A fill valve device in a toilet tank.

Circular vessel with sloping sides used to hold water for washing.

Used for washing posterior areas of the body. It is floor mounted, usually next to a toilet.

The diameter of the drilled holes in a door. 2-1/8" is the most common diameter bore.

Pipe fitting used for joining pipes with different diameters. A bushing is threaded on both the inside and outside.

Cast Iron:
Iron that has been liquefied and poured into a mold to make a tub, sink or other item.

Centerset faucet:
Style of faucet that has the spout and handles combined into a single part. Usually installed on a lavatory sink with 4" center-to-center faucet holes.

Ceramic disk valve:
Type of valve that relies on two-part revolving disks in a sealed cylinder. Each disk has a port in it that, when aligned with the other, will allow water to pass through.

Cock valve:
Valve used for regulating water flow.

A band, sometimes threaded, that can be used to accommodate doors of different thicknesses when installing an entrance set or deadbolt.

Compression fitting:
Pipe connection that is sealed without soldering. As you tighten a nut on one fitting, it compresses a washer around the second pipe, forming a watertight closure.

Compression valve:
Works by lowering or raising a stem. Turning the faucet handle causes the stem to drop or rise, allowing water to pass through the valve.

Concealed hinge:
Concealed hinges are not visible when the cabinet door is closed. These can be European style cup hinges or knife hinges, although knife hinges do leave a visible slot on the edge of the door.

Console sink:
A sink that is mounted to a wall, and rests atop a pair of front legs for additional support.

Straight fitting with female connections (inner threading) at both ends.

The top portion of a toilet seat or the top lid on a toilet's tank.

Locking mechanism most commonly used for entrance doors. Single-cylinder deadbolts feature exterior keyways and interior thumb turns, while double-cylinder deadbolts feature two keyways.

Demountable hinge:
Demountable hinges come in single and double varieties. Single demountables demount from the cabinet door only (requires a special slot be cut into the door for new installations) and screw directly to the edge of the face frame. Double demountables demount from both the door and the frame (both require machining for new installations).

Valves with one inlet that direct water to one of two or more outlets. Diverters are normally used with shower risers, hand showers and kitchen faucet sprayers.

Door Handing:
The way a door swings. Determines how latches and bolts need to be installed for proper operation. Left and right handing are most common for homes.

Door Thickness:
The thickness of a door where hardware is to be installed. Most common door thicknesses are 1-3/8" (interior doors) and 1-3/4" (entrance doors). About 10% of entrance doors are 2-1/4" thick.

Dummy lever/knob:
Often found on bi-fold and French doors, a dummy knob is used to open or close a door that has no latch. These knobs and levers do not require a standard hole to be drilled in the door.

Drainage, Waste & Vent. Pipes in a plumbing system that remove waste water.

Angled fitting for a pipe that changes the direction of a water line.

Emergency egress:
Another term for Interconnect Device, which allows a quick exit from your home in case of fire or other emergency. When installed on a single-cylinder entrance set, the deadbolt and latch retract with the turn of the interior knob or lever.

An opaque, vitreous composition applied to the surface of metal fixtures such as cast iron tubs and sinks.

Decorative, ring-shaped trim used behind a knob, lever or over a keyhole, or used to hide pipe connections to the wall.

Face plate:
The protective covering of the latch or lock system, located in the door.

Female IPS:
Pipe connection where the threads are on the inside of the fitting.

Glass in a fibrous form used in making the body of bathtubs.

Decorative tips found on door hinges, curtain rods and other hardware.

Female Iron Pipe. Standard threads that are on the inside of a pipe fitting.

A hard, dense and durable material that is molded primarily from clay and other minerals, then glazed. Used for sinks, fireclay is fired at a higher temperature than vitreous china, and has greater resistance to extreme heat.

General term that usually refers to faucets, shower valves, tub fillers, or various piping parts such as tees or elbows.

Broad term that encompasses sinks, tubs, toilets and basins.

Ring-shaped trim with a raised rim or lip that connects a pipe to another surface, offering stability.

Flex hose:
Flexible pipe usually made of braided stainless steel.

Flow rate:
The rate which water is discharged from an outlet.

Full inset hinge:
Inset means that the cabinet door is actually recessed into the cabinet opening. With full inset hinges, the front of the cabinet door is flush with the outside of the cabinet face frame when the door is closed.

Gallons per minute. Unit of measurement by which flow rates of faucets and showerheads are measured and regulated.

Gallons per Flush. Unit of measurement which flow rates of toilets are measured and regulated.

Material used to form the surface of some fiberglass bathtubs or showers; a colored, polyester resin.

Hand shower:
Showerhead designed with a handle that is attached to a water supply with a flexible hose.

A joined device or flexible piece on which a door, gate, shutter, lid or other attached part turns, swings or moves.
  hinge types: concealed, demountable, full inset, mortise, overlay, partial inset, self-closing, semi-concealed, wrap

Hose bib:
Outdoor faucet with hose threads on the spout.

ID (inside diameter):
Diameter measurement of the inside of a pipe. Commonly used for sizing pipe.

Opening providing an entrance or intake.

Interconnect device:
Another term for Emergency Egress. Allows a quick exit from your home in case of fire or other emergency. When installed on a single-cylinder entrance set, the deadbolt and latch retract with the turn of the interior knob or lever.

Iron Pipe Size. Pipe thread sizing system. The measurement of the inside diameter of a pipe.

Trademarked name for a tub with jets; often misused to mean any whirlpool tub.

The wood frame around the door. The latch catches on a boring in the jamb, often called the dustbox. Hinges are attached on one side to the door and on the other side to the jamb.

Where the key is inserted and turned to put the lock bolt into the locked position. Schlage keyways are widely used and can be keyed alike by a locksmith, if desired.

Moves in or out with the turn of the knob or lever and either allows the door to open or holds the door shut.

Latch plate:
The protective covering for the deadbolt or mortise latch housing, located in the door jamb.

Bathroom or washroom sink.

Left handing:
Used to determine latch mechanism placement for lever sets, entrance sets, and mortise lock sets. A door has left handing when the hinges are located on the left side of the door as it is pushed open.

Male IPS:
Pipe connection where the threads are on the outside of the fitting.

Male iron pipe. Standard external threads on pipe and fittings.

Mini widespread faucet:
Lavatory faucet with separate spout and handles, small enough to fit 4" center-to-center faucet holes. An alternative to a centerset faucet.

Mixing valve:
Mixes hot and cold water in the valve to set water temperature before delivery.

Mortise cylinder:
A threaded cylinder used specifically for the mortise lock assembly.

Mortise hinge:
A mortise is a shallow recessed area that allows the leaf of the hinge to lie flush with the door or frame.

Mortise lock set:
A box-style lock that is installed directly into an opening that has been mortised in the side of the door. A mortise lock houses both the latch and the deadbolt, making bore spacing particularly important. We recommend that mortise lock installation be done by a locksmith.

NSF/ANSI Standard 61 (NSF-61) is a set of national standards that relates to water treatment and establishes stringent requirements for the control of equipment that comes in contact with either potable water or products that support the production of potable water. The tests vary from a basic cold water test using water at different pH levels, to the more challenging chemical certification. In all cases the equipment is tested before and after exposure to a given fluid to determine whether anything has been leached out or extracted from the equipment. NSF-61 was developed by the National Sanitation Foundation (NSF), a global independent public health and environmental organization, and the American National Standards Institute (ANSI), which oversees the consensus for developing standards for manufacturing and procedures in the United States.

Nominal size:
A size name given to an item that does not necessarily reflect the item's actual dimensions.

Offset hinge:
Used for cabinets or furniture pieces where the door projects out from the frame, requiring an offset to accommodate the space between the surface of the cabinet frame and the door.

O ring:
Typically in a compression fitting, this round rubber washer is compressed to make a watertight seal.

OD (outside diameter):
A common method for sizing pipe, this is a measurement of the diameter of a pipe as taken from the outside edge.

A fitting or combination of fittings consisting of elbows or bends that bring one section of pipe out of line with, but into a line parallel with, another section of pipe. Often used for drains and water supplies.

Open front:
Style of toilet seat where there is an open space at the front. Often it is considered more sanitary in commercial applications.

In a bathtub or sink, a hole and/or drain in which excess water escapes. The overflow drain helps to prevent overflowing and possible water damage to a floor.

Overlay hinge:
The distance that the cabinet door extends past the actual cabinet opening on the hinge side.

Partial inset hinge:
Inset means that the cabinet door is actually recessed into the cabinet opening. If it is partially inset, the recess distance must be measured accurately to determine size needed (3/8" inset is a common partial inset hinge). To determine this dimension, measure the inside step of the recess cut (the part of the door that would extend into the cabinet opening when the door is closed).

Passage latch:
Passage sets are used on doors where no lock system is needed. Interior door sets often have passage function.

Passage spindle:
Piece of hardware that connects two knobs through a door, allowing them to turn freely.

Pipe nipple:
A short pipe that is threaded on both ends and installed between fittings.

Privacy function:
Privacy sets are used on interior doors where a lock system is needed. Commonly found on bathroom and bedroom doors, privacy function sets typically lock on only one side and have an emergency release hole on the other.

Privacy spindle:
Piece of hardware that attaches two knobs through a door, allowing them to turn. Privacy spindles allow turning on one side, while holding the other side stationary to enforce the privacy lock.

P trap:
Section of drain pipe that water is trapped in, blocking gases from escaping through the drain. This P-shaped pipe prevents sewer odors from escaping.

Pedestal sink:
A lavatory or sink in which the bowl is supported by a single column or leg.

Pop-up drain:
Mechanism that relies on a lever or rod to lift the drain stopper.

Powder coat:
Technique for applying paint to metal surfaces. The metal is covered with a powder of dry paint particles and is baked in an oven.

P.O. plug (plug outlet):
Style of drain outlet that is closed by a rubber stopper or plug. Used for lavatories.

Typically white, non-porous material made by heating specific types of refined clay.

Pressure balancing valve:
Maintains a constant water temperature by using a mixing valve that balances incoming hot and cold water supplies.

Polyvinyl chloride. A white plastic used to manufacture water supply pipes.

Physical vapor deposition. Durable zirconium or titanium coating that resists scratches, tarnish and corrosion.

Pipe fitting used for joining together pipes with different diameters. A bushing is threaded on both the inside and outside.

Easy to clean and incredibly durable, a stone-like material made of a poly-resin blend. Material is solid and the same color all the way through, similar to solid surface material.

Right handing:
Used to determine latch mechanism placement for lever sets, entrance sets, and mortise lock sets. A door has right handing when the hinges are located on the right side of the door as it is pushed open.

Inside edge of a toilet bowl, or the edge of a lavatory or sink.

Rim Lock:
An interior door locking device that attaches to the surface of the door, rather than fitting into the door. This type of lock may feature a keyhole with key, or a push button for locking and unlocking. Since rim locks are attached to the door's surface with exposed screws, this type should not be used on exterior doors, as they can easily be forced through.

Riser pipe:
Vertical pipe that feeds water to a fixture.

An escutcheon, usually round, that a knob or lever sits on.

Rough in:
Unfinished ends of drain or supply lines marking where fixtures and drains will be installed. In the case of a standard toilet rough in, it refers to the distance from the finished wall to the center of the outlet pipe.

Safe Water Drinking Act (SWDA):
The Safe Drinking Water Act (SDWA) was originally passed by Congress in 1974 to protect public health by regulating the nation’s public drinking water supply. The law was amended in 1986 and 1996 and requires many actions to protect drinking water and its sources—rivers, lakes, reservoirs, springs, and ground water wells. (SDWA does not regulate private wells which serve fewer than 25 individuals). SDWA authorizes the United States Environmental Protection Agency (US EPA) to set national health-based standards for drinking water to protect against both naturally-occurring and man-made contaminants that may be found in drinking water. US EPA, states, and water systems then work together to make sure that these standards are met.

Seat (or valve seat):
Fixed part of a valve. The stem will move against the seat to open and close the valve.

Self closing hinge:
Self-closing hinges close by themselves if the door is within a certain distance from the closed position. This feature has nothing to do with whether the hinges are concealed or non-concealed, overlay or inset.

Soft-close hinge and slide:
Soft-close hinges or soft-close slides allow the door or drawer to ease to the closed position, gently and quietly. This feature has nothing to do with whether the hinges are concealed or non-concealed, overlay or inset.

Self-rimming sink:
Style of bathroom lavatory or kitchen sink with a finished lip or rim that installs on top of a counter without requiring a metal sink rim.

Semi-concealed hinge:
With semi-concealed hinges, the hinge pin is visible when the cabinet door is closed. On some styles, the screws that mount the hinge to the cabinet frame are visible as well. If they are not visible, then the style is wrap, meaning it wraps around the frame and screws to the edge of the frame.

Semi-recessed sink:
Style of basin that installs partially on top of the counter rather than fully into the counter. The portion that is above the countertop is completely finished, while the portion under the counter may not be finished.

A stationary basin connected with a drain and water supply for washing and drainage.

Slip joint:
Connection made with compression fittings.

Hardware that attaches two knobs through a door. Spindles come in various lengths to accommodate different door thicknesses. Threading type determines what kind of knob will fit onto the spindle.

Section of pipe or threaded fitting that completes a connection.

Stem assembly:
Moving part of the valve that controls the amount and temperature of water released.

Part of the faucet that holds the handle on one end and the washer on the other.

Valve that allows water supply to be cut off to one fixture without affecting the water supply to the entire house or building. Common for use with clawfoot tubs, sinks, and toilets.

Straight stop:
Shutoff valve that is installed between the floor and the faucet or toilet on a supply line, and does not change direction.

Strike plate:
Attached to the door jamb and houses the latch when the door is closed. Often comes with a lip to protect the door jamb when a door is closed without turning the knob.

Tubular part of a lavatory drain that runs from the drain flange to the trap.

T-shaped fitting with three openings.

Thermostatic valve:
Mixing valve that automatically maintains the temperature setting by regulating fluctuations in water temperature at the water inlets and immediately adjusting the ratio of hot and cold water that is discharged by the valve.

A spiral edge on hardware or pipes that allows it to connect to another piece.

Trim Kit:
The outside decorative parts that hide a faucet rough-in; used to supply your sink or toilet with water.

Trip Lever:
Lever that opens and closes the drain on a bathtub's waste & overflow. The flush handle and actuating arm on a toilet tank.

Undermount sink (or Undercounter sink):
A type of sink that is installed beneath a cutout in the countertop.

Union nut:
Joins two sections of pipe using a fitting.

Vacuum breaker:
Anti-siphon device that prevents the backflow of water into the supply system.

A device that regulates water flow.

Valve seat:
Fixed part of a valve. The stem will move against the seat to open and close the valve.

A storage cabinet beneath the counter usually found in bathrooms.

Vessel sink:
Style of basin that installs on top of the counter rather than inside of it.

Vitreous china:
A common material used for bathroom sanitary ware, such as sinks and toilets. A mixture of clay and other minerals, vitreous china is baked at high temperatures after glazing which creates a high gloss, stain-resistant surface.

Waste and overflow:
Drain assembly for a bathtub. The drain at the top (overflow) removes excess water during tub filling and the drain at the bottom (waste) removes water when tub is drained.

WC ("water closet"):

Widespread faucet:
This faucet type measures 8" from each handle's center. It is recognized by its separate spout and handles.

Whirlpool tub:
A bathtub system that recirculates the tub water and mixes in air to create hydro therapy with jet inlets.

Wrap hinge:
A wrap hinge wraps around the cabinet frame from the front to the edge and sometimes partially around the back of the frame. Like the closing styles, this feature has nothing to do with whether the hinges are concealed or non-concealed, overlay or inset.


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