Soil, Drain & Rainwater Glossary
Air Admittance Stack: Valve that allows air to enter the system but not to escape in order to limit pressure fluctuations within the sanitary pipework.
Black Water: Waste water containing faecal matter or urine
Branch Discharge Pipe: Pipe connecting sanitary appliances to a discharge stack or drain
Branch Ventilating Pipe: Ventilating pipe connected to a branch discharge pipe.
Bar (accidental static water pressure): Measurement of pressure, 1 bar is approximately equal to 14.7psi. Accidental refers to - If a blockage in the pipe system occurs
Combined System: A drainage system for both rain and waste water in a single pipe
Connection Bend: First fitting in direction of flow after trap outlet.
Cast Iron: Alloy of cast iron and carbon in which graphite can be present in different forms.
Domestic Water: Water which is contaminated by use and normally discharged from WC, shower, bath, bidet, wash basin, sink, floor gully.
Drainage System: A system composed of drainage equipment, and other components collecting waste water and Discharging by means of gravity; effluent lifting plant may be part of a gravity drainage System.
Discharge Stack: Main (generally vertical) pipe, conveying discharge from sanitary appliances
Drain: Near horizontal pipe suspended within a building or buried in the ground to which stacks or ground floor appliances are connected.
Domestic Sanitary Appliances: Fixed appliances supplied with water and used cleaning or washing. For example: baths, showers, wash basins, bidets, WCs, urinals, sinks, dishwashers, washing machines.
Depth of Water Seal: The depth of water which would have to be removed from a fully charged rap before gases and odours at atmospheric pressure could pass through the trap.
External Diameter: Mean external diameter of the pipe barrel at any cross-section
Electrical Continuity: In situations where equip potential bonding (eathring) is requiredThe earthing of the pipe system.
Flood Level: The maximum level to which waste water can rise in a drainage system
Floor Gully: Discharge fitting intended to receive water from floors either through apertures in a grating or from pipes connected to the body of the gully. A gully may include a trap.
Grey Water: Waste water not containing faecal matter or urine
Internal Diameter (ID): Mean internal diameter of the pipe barrel at any cross-section.
Minimum Internal Diameter: Smallest internal diameter allowed with maximum tolerance
Nominal Diameter (dn or dia): Numerical designation of size which is a convenient round number approximately equal to the Diameter in mm
Non-Domestic Sanitary Appliances: Special sanitary appliances used in commercial kitchens, laundries, laboratories, hospitals, hotels, swimming pools etc.
Rain Water: Water resulting from natural precipitation that has not been deliberately contaminated.
Restrained: Pipework (pipes and fittings) prevented from moving eg. Bracketed - In areas particular where high internal pressures could occur eg rainwater systems
Separate System: A drainage system for draining rain and waste water separately by dedicated pipework.
Sanitary Pipework: Arrangement of discharge pipework , with or without ventilating pipes, connected to a Drainage system
Square Entry: Equal branch junction that is more than 45deg, or has a centre line radius less than the internal pipe diameter
Swept Entry: Equal branch junction that is 45deg or less, or has a centre line radius not less than the internal pipe diameter
Stack Offset: Non-vertical part of a discharge stack
Stack Vent: Extension of a vertical discharge pipe above the highest branch discharge pipe connection that terminates in an end, open to the atmosphere
Sewer: Systems of pipes designed to collect waste water and rainwater from buildings and surface water and to convey them to the point of disposal or treatment.
Trade Effulent: Water after industrial use and processes contaminated/polluted water including cooling water
Trap: Device that prevents the passage of foul air by means of water seal.
Ventilating Pipe: Pipe provided to limit pressure fluctuations within the discharge pipe system
Ventilating Stack: Main vertical ventilating pipe, connected to a discharge stack, to limit pressure fluctuations within the discharge stack.
Waste Water: Water which is contaminated by use and all water discharging into the drainage system, e.g. domestic and trade effluent, condensate water and also rainwater when discharged in a water drainage system.