SYSTEM 1738 is a system fully certified to UL 1738, consisting of pipe, fittings, termination kits, and cement manufactured to strict quality, performance and dimensional standards. SYSTEM 1738 Flue Gas Venting offers a full range of pipe, fittings and termination components that are manufactured from an engineered PVC compound, rated for a maximum flue gas temperature of 149°F and that are fully certified to the rigorous requirements of UL 1738 venting standard for gas-burning appliances, Categories II and IV. Material type, application and temperature rating is included in the pipe print line as well as on the orange and black labels applied to each fitting. All SYSTEM 1738 products have been certified by Intertek and carry an ETL mark as proof of certification.