Before connecting or disconnecting a high-pressure service hose, what must you ensure?

The requirement to ensure that the system is not pressurized before connecting or disconnecting a high-pressure service hose is critical for safety and operational integrity. If the system were pressurized during these actions, it could lead to unintended release of hazardous materials, injury to personnel, or damage to equipment. Ensuring that the system is not pressurized eliminates the risk of high-pressure fluid spray or backflow, which could pose significant dangers.

While it's important for the system to be closed or for the hose to be grounded and clean, the primary focus before interacting with high-pressure hoses revolves around the pressure status of the system. If the system is indeed pressurized, no other precautions might be sufficient to ensure safety when connecting or disconnecting hoses, making this step the most crucial in the process.