Waste coupling is essentially a drain connector that connects the waste pipe from a sink to the drain pipe. This fitting element ensures efficient disposal of water and facilitates the flow of wastewater from a basin to the drainage system. Waste coupling helps avoid leakages and any other kind of damage to the plumbing system. The usual wash basin or sink waste coupling used for a has two parts: an overflow tube and a drain trap. The overflow tube ensures that water does not spill out of the basin in case of a drain blockage. The drain trap, on the other hand, holds water in the pipe’s bend so that sewer gases do not leak into the washroom or kitchen.