We offer the most complete line of loading arm systems and loading-rack equipment for today's bulk loading and unloading requirements. Loading arm systems allow the transfer of gas or liquefied gas from one tank to another through a pipe system. When transferring gas, you will need both a bottom and top loading arm. Whether the application involves tank trucks, railcars, drums or totes, and the moving of petroleum products, liquefied gases, asphalt, solvents or hazardous/corrosive chemicals, OPW Engineered Systems is the preferred loading arm system choice worldwide.