mechanical connectors 
Pipes joined using nuts and threaded metal parts; a gasket is inserted to tighten them, thus preventing leakage.
Threaded part into which two tubes can be inserted; they are made watertight by a gasket tightened with a nut.
Washer made of metal or rubber compressed against the pipe to prevent leakage in the fitting.
Threaded part joining two pipes.
Metal part that screws onto the fitting so that the gasket can be tightened on the tube.