Plug valves are valves with cylindrical or conically-tapered "plugs" which can be rotated inside the valve body to control flow through the valve. Plug valves are simple and often economical. When the plug is conically-tapered, the stem/handle is typically attached to the larger diameter end of the plug. The stem and handle often come in one piece, often a simple, approximately L-shaped handle attached to the end of the plug. The other end of the plug is often exposed to the outside of the valve too, but with a mechanism which retains the plug in the body.