Ball valves come in one, two, or three pieces. One piece ball valves are inexpensive and generally not repaired. Two piece ball valves consist of two separate pieces, with the connection between them being either threaded or a bolt and flange assembly. As you may have guessed, a 3 piece ball valve consists of three pieces, two end caps and a body. The end caps are welded, threaded, or flanged to connect to the pipe on either side.
Why use a 3 piece ball valve?
3-piece-ball-valve For processes that put heavy demands on valves, having a 3 piece valve is more convenient than one or two piece ball valves. When seats and seals need to be routinely replaced, having three pieces allows for easy disassembly, servicing and reassembly without having to do major cutting on the pipe.
Three piece ball valves also allow for elastomers to be changed to accomodate different process conditions, temperatures, pressures and flows.
Need to weld the valve in place? Another benefit is being able to move the body with trim out of the way while welding, ensuring the internals stay intact.
