For handling samples of liquids, gases or liquified gases. The sample cylinders are made from 316 stainless steel. Each end has female pipe threads to accommodate needle valves with a working pressure of 1,800 lbs. All cylinders conform to Department of Transportation Regulations. Supplied without valves. All cylinders that are 1000mL and larger are available with protective caps that screw on to a ring. Caps and rings are factory installed for an additional charge. Working pressures of 3000 and 5000 PSI are available as a special order.