What is a key storage requirement for gas cylinders?

Gas cylinder storage is crucial for safety and compliance with regulations. Keeping gas cylinders away from heat sources is essential because exposure to high temperatures can increase the internal pressure of the gas cylinders, potentially leading to ruptures or explosions. Elevated temperatures can also degrade the integrity of the cylinder and the materials used in their construction. Hence, maintaining a safe distance from heat sources helps ensure the stability and proper functioning of the cylinders, protecting both individuals and property from dangerous situations.

The other listed options present safety hazards or violate standard safety practices. Storing gas cylinders in wet areas could lead to corrosion, which can compromise the cylinder's integrity. Allowing them to obstruct safety exits creates risks for emergency evacuations, posing danger during emergencies. Stacking cylinders horizontally is generally not advisable because it can lead to instability, tipping over, and potential damage to the valves or welds. Proper vertical storage is part of best safety practices in handling gas cylinders.