Final answer:
The scavenge isolator valve must be closed when working around the breech to avoid inadvertent breech motion.
Step-by-step explanation:
The scavenge isolator valve must be closed when working around the breech. Failure to close the valve could result in inadvertent breech motion.
The scavenge isolator valve is an important safety feature in engineering, specifically in marine diesel engines. It is responsible for preventing the escape of scavenging air from the cylinder through the exhaust ports, which helps maintain proper combustion.
By closing the valve, any potential movement within the breech area is restricted, reducing the risk of accidents or damage to the engine. It is crucial to follow safety protocols and ensure the isolation valve is properly closed to maintain a safe working environment.