Holds clamping pressure until released by a separate pilot pressure line (allows only one-way flow until released). Can be used as a safety device in case the fluid line to the fixture could become damaged. Can also be used to prevent workpieces from floating between opposing clamps. Leakage-free valve design with spring-loaded ball seat. The version shown here is used for in-line mounting with standard fittings and exposed fluid lines. Also available in a manifold-mounted version.