While it is technically possible to transport refrigerant cylinders in a vertical position, it is not recommended. Transporting cylinders vertically can increase the risk of damage or leakage, as the cylinder’s valve and other components may be subjected to excessive stress. Additionally, vertical transportation may not comply with regulatory requirements, such as those outlined in the DOT’s HMR. It is recommended to transport refrigerant cylinders in a horizontal position, securely fastened to prevent shifting or falling.