Drain Dictionary

Drainage Structures

Traps, gullies, pits, openings and the other physical parts of a drainage system.

Benching The shaped concrete floor inside a manhole or pit that channels flow smoothly through the chamber and gives workers a standing surface. Grease Trap A tank installed on commercial kitchen drains that slows wastewater so fats and solids separate out before the water enters the sewer. Gully Trap A water-sealed fitting that collects wastewater from external pipes or fixtures and directs it into the sewer drain while blocking odours with its water seal. Inspection Opening A capped access point (commonly called an IO) built into a drain so it can be inspected, tested and cleared without digging. Manhole A large access chamber — formally a maintenance hole or access chamber — allowing entry to sewers and stormwater mains for inspection and maintenance. Overflow Relief Gully A drainage fitting (usually a grated outlet in the yard) set lower than indoor fixtures, designed to overflow outside if the sewer blocks — instead of sewage ba Reflux Valve A one-way flap valve installed in a drain that lets wastewater flow out but slams shut against any flow coming back — protection against sewer surcharge. Riser A vertical pipe section that brings a buried drain fitting — like an inspection opening or boundary trap — up to surface level for access.

More Categories

Pipes & Materials (4) Blockages & Causes (14) Inspection & Technology (9) Repair Methods (6) Cleaning & Clearing (3) Plumbing Fixtures (3) Sewer Systems (8) Stormwater (8) Trade Terminology (5) Regulations & Standards (5) Water Flow & Hydraulics (5) Tree Roots & Vegetation (2) Maintenance & Prevention (1)

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