We've put together a list of the most common PVC terms and jargon and made them easy to understand. All terms are listed in alphabetical order. Find the definition of the PVC term you're wondering about below!
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.
Belled End – bell end pipe is made to flare out at one end, allowing another piece of pipe to slide into it without the need for a coupling. This option is usually only relevant for use in long stretches of straight pipe line.
Bushing – a fitting used to reduce the size of a larger fitting. Sometimes called a "reducer bushing"
Class 125 – this is a type of large diameter schedule 40 PVC fitting that is similar in every way to a standard schedule 40 fitting EXCEPT that it has not been through testing. Class 125 fittings are generally less expensive than standard sch. 40 PVC fittings of the same type and size and are therefore used commonly for applications where tested and approved fittings are not required.
Compact Ball Valve – a relatively small ball valve usually made of PVC that offers a simple on/off function. The valve cannot be taken apart or easily repaired and so it is generally the least expensive ball valve option.
Coupling – a fitting that slips over the ends of two pieces of pipe to join them together
CPVC (Chlorinated Polyvinyl Chloride) – a material similar to PVC in its rigidity, corrosion resistance, and chemical resistance. CPVC, however, has a higher temperature tolerance than PVC. The maximum working temperature of CPVC is 200F compared to 140F (standard PVC)
DWV – stands for Drain Waste Vent . A system of PVC created to handle non-pressurized applications.
EPDM – (Ethylene Porpylene Diene Monomer) a type of rubber used for sealing PVC fittings and valves.
Fitting – part of a pipe line used to fit together sections of pipe. Fittings can come in all shapes, sizes, and materials.
FPT (FIPT) – aka Female (Iron) Pipe Thread. This is a type of threading that is found on the inside lip of a fitting, allowing connection to a MPT or male pipe threaded end. FPT/FIPT threading is commonly used for PVC and CPVC piping systems.
Furniture Grade PVC – a type of pipe and fitting made especially for use in non-liquid handling applications. Furniture grade PVC is not rated for pressure and should only be used for structural/recreational applications. Unlike standard PVC, furniture grade PVC is made without any markings or obvious blemishes.
Gasket – a seal that goes between two surfaces to create a water-tight seal that is leak-free.
Hub – a type of DWV fitting end that allows pipe to slide into the end.
ID – (Inside Diameter) the greatest distance between the two inside walls of a piece of pipe.
IPS – (Iron Pipe Size) a common sizing system used for PVC pipe, also known as Ductile Iron Pipe Standard or Nominal Pipe Size Standard.
Modular Seal – a seal that can be put in place around a pipe to seal the space between the pipe and the surrounding material. These seals are commonly made up of links that are assembled and tightened to fill the space between the pipe and a wall, floor, etc.
MPT – aka MIPT, Male (Iron) Pipe Thread – a type of threaded end found on PVC or CPVC fittings where the outside of the fitting is threaded to facilitate connection with a female pipe threaded end (FPT).
NPT – National Pipe Thread – the US standard for tapered threads. This standard allows NPT threaded fittings to fit together in a water-tight seal.
NSF – (National Sanitation Foundation) a system of standards for public health and safety.
OD – Outside Diameter – the longest straight distance between the outside of a piece of pipe on one side to the outside of the pipe wall on the other side. A common measurement in PVC and CPVC piping.
Operating Temperature – the temperature of the media and immediate surroundings of a pipe line. PVC has a maximum recommended operating temperature of 140 degrees Fahrenheit.
O-Ring – a ring shaped gasket usually made from an elastic material. O-rings are found in some PVC fittings and valves and are used a seal to create a water-tight joint between two (usually moving or removable) pieces.
Pipe Dope – the slang term for pipe thread sealant. This is a pliable material that is applied to the threads of fittings before installation to ensure a water-tight and long-lasting seal.
Plain End – standard end type for pipe. Unlike belled end pipe this pipe is the same diameter the entire length of the pipe.
PSI – Pounds per Square Inch – a unit of pressure used to describe the maximum recommended pressure to put on a pipe, fitting or valve.
PVC (Polyvinyl Chloride) – a rigid thermoplastic material that is corrosion and chemical resistant. Used commonly in a wide range of commercial and consumer products around the world, PVC is known for its use in media handling pipe.
Saddle – a fitting used to create an outlet in pipe without cutting or removing the pipe. Saddles generally clamp on to the outside of a pipe allowing a hole to then be drilled for the outlet.
Sch – abbreviation for Schedule – the wall thickness of a piece of pipe
Schedule 40 – usually white, this is a wall thickness of PVC. Pipe and fittings can come in various "schedules" or wall thicknesses. This is the most commonly used thickness for home projects and irrigation.
Schedule 80 – 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 – an end type on a pipe fitting that allows the pipe to slide into the fitting to create the connection. In the case of PVC and CPVC, a solvent cement is used to weld the two pieces together.
Solvent Weld – a method of joining pipe and fittings by applying a solvent chemical softener to the material.
Spigot (Sp or Spg) – a type of fitting end that fits inside of another socket fitting of the same size (Note: This fitting does NOT fit inside of pipe! No pressure fittings are designed to fit inside of pipe)
Threaded – a type of end on fittings in which a series of interlocking tapered groves come together to form a water-tight seal.
True Union – a style valve that has two union ends that screw off to allow the valve to be removed from the surrounding pipe line after installation.
Union – a type of fitting used to join two pieces of pipe. Unlike couplings, unions use a gasket seal to create a removable connection between pipe.
Viton – a brand name fluoroelastomer used in gaskets and o-rings to provide a seal. Viton is a registered trademark of DuPont.
Working Pressure – the recommended pressure load on a pipe, fitting or valve. This pressure is usually denoted in PSI or pounds per square inch.
