are threaded. Here are the most common drain fittings. The list doesn't include couplers and ordinary bends, because they're ...

Pipes are hollow cylinders of uniform material with a certain ... of the system requiring frequent disconnection and reconnection during operation. Threaded fittings - Fittings with screw threads ...

Hydraulic pipes are larger diameter hydraulic tubes ... are convenient for sections of the system requiring frequent disconnection and reconnection. Threaded fittings have screw threads (built-in ...