Why is it essential to ensure a valve is shut before removing the cap of a sounding tube?

Ensuring that a valve is shut before removing the cap of a sounding tube is crucial primarily to maintain safety during maintenance. If the valve is open, fluid from the system could escape unexpectedly, leading to potential hazards such as spills or exposure to pressurized liquids. By shutting the valve, the risk of injury or accidents is significantly minimized, safeguarding both the personnel performing maintenance and the integrity of the equipment.

While preventing liquid overflow is a consideration, the broader context of safety encompasses a range of factors including reducing the risk of accidents or exposure to hazardous materials. Keeping the valve closed until maintenance is complete is a standard procedure that emphasizes safety as the top priority in operational protocols.