Ball Valves can be found in common household applications to the harshest of cryogenic environments. They typically involve a quarter turn valve which uses a pivoting ball to control the flow of media through it. They make excellent isolation valves because of their ease of use and versatility.
A common problem with ball valves, especially in cryogenic applications, is the fact that they trap expansible media within the ball when closed. If the pressure or state within this media changes, it can rupture the ball valve with explosive consequences. The last thing you want is an incorrectly specified ball valve with the potential to turn into a ticking time bomb.