(1) Globe Valve: Used for opening and closing fluid in pipelines. (2) Control Valve: Used for adjusting and maintaining the specified pressure and flow of the medium. (3) Check Valve: Used to automatically prevent reverse flow of the medium in the pipeline. (4) Safety Valve: Prevents media pressure from exceeding specified values by discharging excess media outward. (5) Steam Trap: Used to drain condensate from steam pipelines and equipment. (6) Blowdown Valve: Used to drain sewage containing mud and salt from steam drums and headers. (7) Pressure Reducing Valve: Used to reduce media pressure. (8) Others include temperature and pressure reducing valves, air valves, etc. Viessmann wall-hung boiler Q&A; According to their purposes, into how many types can valves be divided? Source of information: http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3778856