Glossary

Term	Description
Anti-syphon	A type of waste trap, which is designed to prevent self syphonage (where the water seal is sucked out of the trap). Normally, this occurs due to the waste falling vertically before at an even gradient to the stack, thus creating a vacuum.
Appliances	Examples include a WC, sink, basin & bath, as well as a washing machine or dishwasher.
Compression	A screw type method of jointing. The fitting has a screw cap and a ring seal, which, when tightened, makes a watertight seal.
Cross flow	Where waste from one appliance crosses the soil stack into the waste run of another appliance.
Gravity drainage	Drainage which runs through pipework installed to a fall, and not therefore under pressure.
MuPVC	Modified Polyvinyl Chloride (able to withstand higher temperatures, generally used for waste systems)
Offsets	A vertical change in direction, normally of between 30 and 45 degrees.
Pan connector	Also called a WC connector. The connection from a WC to the soil stack.
Pipe support	A system of metal brackets which allows pipework to be installed horizontally, normally suspended under a floor. Used in commercial situations.
PVCu	Polyvinyl Chloride (unplastised)
Ring-seal	Joint with a seal to make it watertight
Socket	Female type connection
Soil Stack	Normally 4" or 110mm pipe. Installed vertically in a house (either internally or externally). Waste and WC connections are connected to the stack, which in turn connects to underground drainage pipe at ground level.
Solvent Weld	Using a solvent to adhere two surfaces (used with PVCu or ABS)
Spigot	male type plain connection
Stub stack	A short soil stack which is used to connect a group of ground floor appliances.
Vent Ventilation	A soil stack must be ventilated at high level to prevent a vacuum from forming or a build up of toxic or explosive gases.
Waste Trap	A fitting required where waste water is discharged to drain. The trap creates a water seal, preventing any odours from the drain to pervade the house.
WC connector	Also called a pan connector. The connection from a WC to the soil stack.
WC manifold	A system of WC connections made in line. For use in commercial situations, allowing a range of toilets to be connected in line above floor level, eliminating the need for specially fabricated fittings.