ABS 90° Cross pieces are designed to link four pieces of ABS pipe together at right angles to each other.
The flow characteristics of ABS Cross pieces are different depending which branch of the cross the fluid is entering and leaving. If going straight through, the friction loss is quite low, but when fluid is also going through right angles (one way or the other), the flow dynamics become very complex and friction loss is much greater. It is important to note that fluid exiting three branches of a cross will not be evenly distributed due to turbulence inside the fitting. The ABS cross pieces have solvent cement welding sockets at each end.