Zhejiang Shangzhuan Fan (浙江上专风机有限公司), formerly Shangyu Shangzhuan, is based in Shangyu, Shaoxing. It manufactures centrifugal cabinet fans, mixed-flow and axial fans, and roof fans, including HTF high-temperature fire smoke exhaust fans and dual-use fire/ventilation roof fans. It also makes matching valves and accessories. Its fire dampers and smoke exhaust valves hold fire product certifications 5982026ZY060087 and 5982026ZY060092 from the Tianjin Fire Research Institute of the Ministry of Emergency Management.