To be of value, valves must be attached to a piping system. How that attachment occurs has changed over time. For decades, screwed or flanged connections were the only way to go. However, the perfection of fusion welding techniques in the 1930s led the way for new methods of joining piping components, including valves. These new ways are the butt-weld (BWE) (Figure 1) and socket-weld (SW) (Figure 2) end connections.