Uni-Chem™ Standard Chemical Service PS Composite Hose. Specifically designed for in-plant liquid transfer operations as well as tank truck delivery and rail car loading. These hoses offer supreme flexibility in comparison to rubber hoses. This flexibility aids operators when handling both charged and uncharged hoses. Constructed with multiple plies of polypropylene films and polyester vapor barrier, these hoses can be operated at positive pressure or full suction.