Trunnion ball valve is a valve that opens by turning a handle attached to a ball inside the valve. It has a mechanical means of anchoring the ball at the top and the bottom; this design is usually applied on larger and higher pressure valves. The ball has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur.
Truss Bridges are used with steel bridges and produce light & efficient structures. They are less common on concrete structures because of the complex design and construction of the joint between the diagonals of the truss and the deck slabs. The design of the truss structure allows applied loads to be resisted primarily by axial forces in straight truss members. A truss bridge is a bridge composed of connected elements, which is stressed from tension, compression or sometimes both in response to dynamic loads.