In case the flow of a fluid is to be switched from one pipeline to another pipeline, there needs to be a changeover valve in place. Also called as switchover valve and selector valve, this kind of valve can be used in dual filtration system, multiple heat exchangers, and dual or multiple production lines. Where there are dual devices, this changeover valve is essential. For instance, in case of pressure relief devices, this valve ensures service of at least one of the two devices. And it ensures complete relief flow at the time of changeover.