Drainage Appliances and Equipment
This category applies to the apparatus that enables flow and access to the drainage system. In effect all the drainage appliances other than the pipework itself. This is a fairly large topic, so we will cover the most commonly used drainage appliances.
The most obvious are items such as manholes, inspection chambers and rodding eyes. These are placed in suitable areas to enable access to the system for maintenance purposes and have covers that can be removed for this purpose.
Other common appliances include gullies, which allow the outfall of surface or grey water via a grilled, surface-level water trap. These are commonly found at the base of surface water downpipes. Another common method of surface water dispersal is by use of a channel drain. These channels are normally covered by a grill and outfall to the below-ground system by a water trap (similar to a gulley).
Victorian properties may have a different type of trap on the main outfall drain that is designed to prevent smell coming back from the public sewer (in fact every water trap on any appliance is designed to stop smells). These are called Buchan or Winser traps, although in some areas they are called interceptors.