What should protect valves on compressed air cylinders when they are being transported or stored?

Valves on compressed air cylinders should be protected by covers during transport or storage. Covers are specifically designed to shield the valves from physical damage, contamination, or debris that could interfere with their safe operation. When compressed air cylinders are moved or stored, bumps or falls can occur, which may lead to damage or accidental opening of the valve. By using covers, you ensure that the valves remain intact and secure, reducing the risk of injury or malfunction.

Other options may not provide adequate protection. While bags could potentially secure the cylinder, they lack rigidity and may not effectively shield the valves. Wooden crates can offer protection but might not be as practical or readily available for all circumstances. Metal shields could provide significant protection, but they may be heavy and cumbersome, making them less suitable for transport or storage. Covers strike an optimal balance between protection and convenience.