An isolation valve is a valve designed to separate or isolate the fluid media from the inner workings of the valve. These are used for diverting process media, facilitating maintenance, equipment removal and shutdown. In a solenoid valve this is typically accomplished using a diaphragm. Also known as a diaphragm valve, the only materials wetted by the fluid media are the valve body and the diaphragm itself. The plunger and spring are isolated from the fluid media. Isolation valves are typically desirable in sensitive applications such as scientific and medical instrumentation, where engineers want to maintain the chemical integrity of a fluid sample.