ISO 16139:2006 specifies requirements for the design, functional characteristics and manufacture of gate valves made of thermoplastics materials intended for isolating service, their connection to the pipe system, the body materials and their pressure/temperature rating between -40 degrees Celsius and +120 degrees Celsius, for a lifetime of 25 years, and also specifies their tests.. ISO 16139:2006 is applicable to hand- or power-operated valves to be installed in industrial pipe systems, irrespective of the field of application and the fluids to be conveyed. This International Standard is concerned with the range of DN 10, DN 15, DN 20, DN 25, DN 40, DN 50, DN 65, DN 80, DN 100, DN 125, DN 150, DN 200, DN 250, DN 300 and DN 350, and the range of PN 6, PN 10, PN 16, and Class 150.