A valve in a sewer line that prevents sewage from flowing back into a house.
A backflow prevention device is used to protect water supplies from contamination or pollution.
A device installed in a drainage
extendible: capable of being lengthened
In software engineering, extensibility (sometimes confused with forward compatibility) is a system design principle where the implementation takes into consideration future growth.
(extendability) The ease with which a system or component can be modified to increase its storage or functional capacity. Syn: expandability; extensibility. See also: flexibility; maintainability.