What can occur if a horizontal cylinder is not stored in its proper position?

If a horizontal cylinder is not stored in its proper position, liquid propane can enter the vapor system. This is significant because propane cylinders are designed to store gas vapor above any liquid propane within. When the cylinder is stored horizontally, liquid propane can flow into the vapor line that is meant to supply gas. This can lead to various issues, including improper combustion in appliances and potential safety hazards due to liquid entering systems that are only meant to handle gases. Proper storage ensures that only vapor is released, maintaining effective and safe operation of propane-fed equipment.