A nuclear plant specified a very compact pneumatically-operated actuator for a plant firefighting system. With no springs for the failsafe function, it had to be provided with a stored energy accumulator. The application was specified as: 1. A safety-related actuator application in a nuclear power plant 2. Environmental and seismic qualifications to IEEE 382, IEEE 344, and IEEE 323, as well as plant-specific requirements 3. Y-pattern type globe valve 4. 23.6 kN (5,300 lb) thrust requirements 5. 35mm (1.375 in) required stroke 6. 45 Barg (652 psi) available supply pressure 7. Mechanical spring prohibited 8. Fast operation (close stroke time of less than three seconds) 9. Compliance with European design codes (CE & PED).
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