Final answer:
Pneumatic position-detector valves are used in hazardous environments to eliminate ignition risks posed by electrical sparks. They use pressurized air or gas to function and enhance safety by avoiding the generation of electrical sparks in explosive atmospheres.
Step-by-step explanation:
Pneumatic position-detector valves are sometimes used in applications where electrical limit switches are not safe because of the risk of explosions from an electrical spark. These valves are part of a control system in various industries, especially where flammable gases or dust are present. The pneumatic position-detector valves eliminate the risk of ignition from electrical components as they use pressurized air or gas to function, hence no electrical spark is generated. These types of valves are crucial for maintaining safety in hazardous environments and ensuring that the processes can be controlled without introducing ignition risks.