When fully open, indicating valves must stay open for how long at a minimum before closing?

Indicating valves must remain fully open for a minimum of 5 seconds before closing to ensure that any necessary observations can be made. This period allows enough time for personnel to verify that the indication accurately reflects the status of the system, which is critical for safety and operational assessments. In fire protection systems, validating that a valve is functioning correctly is paramount; a brief opening may not provide sufficient assurance that the valve's position is registered correctly, especially in systems with high flow or turbulent conditions. This standard aligns with industry practices aimed at fostering reliable operation and safety during inspections and maintenance activities.