Question 35 1AE01 - First Assistant Engineer

The Correct Answer is D **Explanation for Option D (Correct):** Before performing any maintenance or repair work on a hydraulic system, especially one equipped with accumulators, safety protocols require that all stored energy be neutralized or released. Accumulators store significant energy, usually in the form of pressurized nitrogen gas acting on hydraulic fluid. This stored energy must be safely bled off (released) to zero pressure before work begins to prevent serious injury, sudden component movement, or high-pressure fluid injection if components are disconnected. Bleeding off the stored energy ensures the system is de-energized and safe to work on. **Explanation for Other Options (Incorrect):** * **A) drain the accumulators and purge with oxygen:** This is highly incorrect and dangerous. Accumulators are typically charged with dry nitrogen (an inert gas). Purging with oxygen, especially in the presence of hydraulic fluid (an oil), creates a severe fire and explosion hazard. Furthermore, draining the accumulators is only done if they are being removed or replaced, not as the standard pre-work safety step for the overall system. * **B) pump the hydraulic fluid into the accumulators to prevent fluid loss:** Pumping fluid into the accumulators increases the pressure and thus increases the stored energy. This is the opposite of the required safety procedure. Preventing fluid loss is a secondary concern compared to ensuring safety by de-energizing the system. * **C) completely charge the accumulators to prevent system energy loss:** Charging the accumulators is equivalent to maximizing the system's stored energy. This creates the most dangerous working condition possible and completely violates fundamental hydraulic safety practices. The goal is to dissipate, not maximize, stored energy.