Chen Full(China) was found in 2002 that specializes in the design and manufacture of Teflon coated ductwork (Stainless steel welded ductwork with inside ECTFE coating) has been approved by Factory Mutual Research Approval Standard Class Number 4922----Stainless Steel Welded Duct(SUS304 or SUS316) with ECTFE Coating, ECTFE(Teflon) is fluorin phosphorus high polymer chemicals, which has excellent and high heat prevention ,  corrosion resistance, insulativity , and low combustibility . Now it is mostly used in semiconductor industry , chemical engineering corrosion prevention ,acid or alkali resistant system. Because of the excellent corrosion resistance , Stainless steel welded duct (SUS 304 or SUS 316L) has been mostly used in various high tightness technics exhaust system. On the other hand, We also custom design and build duct accessories such as ducting elbows, reducers,tees, and dampers,etc.for various industries on a variety of applications. Our products are all modular designed to be fast hooked up and is also flexible for field repair and modification. We own a complete facilities to offer a full gamut of services: design, Plasma/X-Ray/CNC auto-cutting, Tig atomatic welding, sandblasting,cleaning, and ECTFE coating. Thus, we can make our quality and delivery time controlled very well. Our experienced staff have worked on just about everything that was ever made out of metal and have the knowledge to do it in your choice of products