Common Terms for PVC Pipe, Fittings, and Parts

 

Common Terms for PVC Pipe, Fittings, and Parts

ABS or Acrylonitrile Butadiene Styrene is a group of plastics made from polymers with prescribed percentages of acrylonitrile.

Adapter is a fitting that joins two different pipes together. It can also join threaded with nonthreaded pipe.

Aging is the act of exposing materials to an environment for a period, or the effect on materials that have been exposed to an environment for an extended.

ASTM stands for American Society for Testing and Materials. Known today as ASTM International, this is a leader in international standards use for safety, quality and consumer confidence. There are a number of ASTM standards that apply to PVC and CPVC pipe and fittings.

Beam Loading is the process of applying specified force to a piece of pipe that’s supported at two points. This is usually expressed in pounds per distance between the centers of the supports.

Belled End pipe is made to flare out at one end, which allows another piece of pipe to slide into it without the aid of a coupling. These are typically only used in long stretches of straight pipeline.

Bend is often used in place of Elbow which changes the direction of a pipeline a certain number of degrees.

Cap is a type of stop that goes over the outside diameter of the pipe to cap.

Class 125 is a large diameter schedule 40 PVC fitting that is similar in every way to a standard schedule 40 fitting with the exception that it has not been through testing. These fittings are typically less expensive than standard Sch 40 PVC fittings, and are to be used in applications where tested and approved fittings are not required.

Cleanout is a fitting with a removable element that allows access to drains without the removal of plumbing fixtures.

Compact Ball Valve is Usually made of PVC and is a small ball valve that has a simple on/off function. Since this valve cannot be taken apart, it is not easily repaired and is often one of the least expensive ball valves.

Condensation is a chemical reaction that involves the combination of molecules which results in the elimination of a simple molecule, such as water, and the formation of a more complex compound of greater molecular weight.

Coupling is a simple type of fitting that connects two pipes (or a pipe and another fitting together) by slipping over the pipes. Some couplings have the capabilities of reducing, allowing a smaller diameter pipe to be connected to a larger diameter pipe (or vice versa).

CPVC aka Chlorinated Polyvinyl Chloride is similar to PVC in its corrosion and chemical resistances, as well as in its rigidity. However, CPVC boasts a higher temperature rating than PVC with a maximum working temperature of 200°F.

Crazing refers to small, fine cracks on or under the surface of a plastic.

Cross is a fitting that joins 4 pipe sections together.

Cure means to change the properties of a polymer to a stable, usable and final state, through the use of chemical agents, heat or radiation.

Degradation is the process where the chemical structure, appearance, or physical properties of plastic starts to deteriorate.

Dimensional Stability refers to the capability of a plastic part to maintain its original shape and dimension under standard conditions of use.

Dynamic Pressure is the pressure when water is flowing.

DWV is an abbreviation for Drain Waste Vent, which is a system of PVC for handling non-pressurized applications.

Elasticity is the property of plastic that allows it to return to its original dimension after deformation.

Environmental Stress Cracking are cracks that develop when a plastic part is subjected to incompatible chemicals and is put under stress.

EPDM or Ethylene Propylene Diene Monomer is a type of rubber used for sealing PVC fittings and valves.

Extrusion refers to the process used to continuously form a shape by forcing a heater or unheated plastic through a shaping orifice.

Fillers are relatively inert materials added to plastic to modify its strength, permanence, or working properties.

Fitting is used in piping systems to join together sections of pipe. Fittings are available in a variety of materials, sizes, and shapes.

Flush Bushing is a fitting that joins two pipes of different diameters together. The smaller pipe screws into the female end and the larger pipe to the male end.

FPT (FIPT) stands for Female (Iron) Pipe Thread. This threading found on the inside lip of a fitting allows for connection to a MPT (male pipe threaded end). FPT/FIPT threading is commonly used for systems with PVC and CPVC piping.

Furniture Grade PVC is a type of PVC that is not rated for pressure and is used for non-liquid handling applications. It is commonly used for structural or recreational applications. Unlike standard PVC, furniture grade PVC does not have any markings or obvious blemishes.

Fuse is to join plastic parts together by softening the material using solvents or heat.

Gasket is a seal that fills the space between two surfaces in order to prevent leakage.

Hoop Stress is the circumferential stress that is imposed on a pipe wall when exposed to an internal pressure load. This is usually expressed in pounds per square inch.

Hub is a term describing a DWV fitting. No hub adapters enable a pipe to slide into one end of the fitting.

ID stands for Inside Diameter and is the measure of distance from one inside wall of a pipe to the inside wall of the other side of the pipe.

Impact Strength is the measurement of a plastic part’s ability to withstand the effects of dropping or striking.

Injection Molding is the process used to form a shape by forcing a heated plastic, under pressure and in a fluid state, into the cavity of a closed mod.

IPS stands for Iron Pipe Size. Also known as Ductile Iron Pipe Standard or Nominal Pipe Size Standard, this is a common sizing used for PVC pipe.

Lubricant refers to any substance that reduces the friction between moving solid surfaces.

Modular Seal is a seal that is placed around a pipe to fill and seal the annular space surrounding the pipe. Commonly made up of links, these seals are assembled and tightened to fill the space between the pipe and a wall, floor, etc.

MPT (aka MIPT, Male (Iron) Pipe Thread) is designed with threaded ends on the outside to connect with a female pipe threaded end (FPT), which has threads on the inside. PVC and CPVC fittings often have MPT ends.

NPT is the US standard for tapered threads and stands for National Pipe Thread. These ends allow for pipes and fittings to fit together with a water-tight seal.

NSF stands for the National Sanitation Foundation, a system of standards for public health and safety.

OD stands for Outside Diameter and is a common measurement for PVC and CPVC pipes. Measuring the face of the pipe, OD is the straight distance from one outside edge of a pipe to the other outside edge.

Operating Temperature describes the temperature of both the media and surroundings of a piping system. PVC pipe’s recommended maximum operating temperature is 140 degrees Fahrenheit.

O-Ring is are found in some PVC fittings and valves and are used to create a water-tight joint between two pieces. This ring-shaped gasket sits right inside the valves and fittings, and is made from an elastic material.

Pipe Dope is a slang term for a chemical sealant. This pipe thread sealant ensures durable, leak-free seals by softening the thermoplastics in the pipe and fitting until they meld together.

Plain End describes a type of pipe end that has the same diameter as the rest of the length of pipe. Plain End pipes are often contrasted with belled end pipes. See Belled End.

Plug is used to seal an unused fitting outlet.

Primer is a solvent used to soften surfaces prior to the application of cement.

PSI (aka Pounds per Square Inch) is a common unit of measurement to describe the maximum pressure a pipe, fitting, or valve can handle without failure.

PVC stands for Polyvinyl Chloride. This rigid thermoplastic is corrosion and chemical resistant. PVC is known as a media handling pipe and is commonly used in commercial and consumer products around the world.

Reducer Coupling is a fitting that can join two pipes of different diameters together.

Saddle is a type of fitting that allows for a branch to be added to an existing piping system without completely deconstructing the system. These fittings clamp around the outside of a pipe to create a tee joint for a new line to be added to the system. A small hole is drilled into the top of this tee connection, allowing liquid flow to continue throughout the entire system.

Sanitary Fittings are fittings that join the pipes of a DWV system together. They are designed to allow solid material to pass through without clogging.

Sch an abbreviation for Schedule meaning the wall thickness of a piece of pipe.

Schedule 40 indicates the wall thickness of PVC and is usually white. When working on home projects and irrigation, Sch 40 is commonly used.

Schedule 80 is usually gray in color, schedule 80 PVC pipe and fittings have a thicker wall than schedule 40 PVC. This makes sch 80 able to withstand higher pressures. Sch 80 PVC is commonly used for commercial and industrial purposes.

Slip – See Socket

Socket This common fitting end type allows pipes to slip into fittings, creating a connection. To make this connection permanent and water-tight, PVC and CPVC require solvent welding.

Solvent Weld (Cement) is the process of melding pipe and fittings together by using a solvent chemical softener.

Spigot (Sp or Spg) designates the type of fitting end for a pressure fitting. Spigot ends fit inside socket ends of the same size. Spigot fittings should NOT be used to fit inside a pipe.

Static Pressure is the pressure when no water is flowing.

Street Elbows are a 90° fitting that has a male end and a female end.

Stress Crack is an external or internal crack in plastic that is caused by tensile stresses less than its short-time mechanical strength.

Tailpiece is a drain fitting that protrudes into the trap.

Thermal Expansion is the increase in a length of plastic due to a change in temperature.

Thermoplastics are a group of plastics that can repeatedly be softened by heating and hardened by cooling.

Trap is a curved or V-shaped section of drain line that prevents sewer odors from escaping.

Threaded is a type of connection on pipes and fittings. Threaded ends are tapered grooves that create water-tight seals. Additionally, this fitting end type allows for easy detachment and does not require welding.

True Union refers to a type of valve that is composed of two union ends that twist off to allow the main part of the valve to be easily removed for piping repair or replacement.

Unions are fittings that use gasket seals to connect two pipes together. These fittings make repairs easy in that only one pipe needs to be turned in order to disconnect the two pipes.

Viton is a brand of FKM and is trademarked by DuPoint. It is a high-performance fluoroelastomer, and this synthetic rubber compound is often used in O-rings and gaskets. Viton O-Rings are known for their durability in high temperatures, environmental challenges, and contact with chemicals.

Weld Line (Knit Line) is a mark on the molded plastic part, formed by the union of two or more streams of plastic flowing together.

Working Pressure is usually stated in PSI (Pounds Per Square Inch), and the working pressure is an operating pressure on a pipe, fitting, or valve. It indicates how much pressure a pipe can operate with a safe margin without failure.

Wye is a fitting with three openings used to create branch lines.