News

Blind flanges can be classified according to material, sealing surface form, connection mode, etc. as follows:
Classification according to material
Carbon Steel Blind Flanges: Commonly used carbon steel materials are Q235, 20# steel and so on. With low cost and high strength, it is suitable for general low-pressure, non-corrosive media piping system, such as ordinary water, air, steam and other media transportation pipeline.
Stainless steel blind flange: common stainless steel materials are 304, 316, 316L and so on. With good corrosion resistance, oxidation resistance and hygiene performance, widely used in chemical, food, pharmaceutical, beverage and other industries for corrosion resistance and high hygiene requirements of piping systems.
Alloy steel blind flange: 15CrMo, 12Cr1MoV and other alloy steel materials. With high strength, high temperature resistance and creep resistance, it is suitable for high temperature, high pressure and certain corrosive media, such as high temperature and high pressure pipelines in the petrochemical industry, steam pipelines in the electric power industry.
According to the sealing surface form classification
plane sealing blind flange: the sealing surface is flat, simple structure, easy processing. Suitable for piping systems with low pressure, clean media and no particles, such as some normal temperature and pressure water supply and drainage pipelines.
Convex sealing blind flange: the sealing surface is convex, which can provide better sealing performance when used with concave flange. It is suitable for medium pressure piping system, such as compressed air piping and medium pressure hot water piping in some industrial plants.
Concave face sealing blind flanges: used with convex face flanges, they have better sealing performance and can be used in medium pressure piping system, which can effectively prevent medium leakage.
Tongue and groove face sealing blind flanges: the sealing face consists of tongue and groove face, which can realize high-precision sealing fit. It is suitable for high-pressure, flammable and explosive, toxic and hazardous media pipelines which require high sealing requirements, such as natural gas transportation pipelines, chemical material transportation pipelines and so on.
Ring connecting surface sealing blind flange: adopting metal ring as sealing element, it has superior sealing performance and can withstand high temperature and high pressure. Commonly used in high pressure, high temperature pipeline systems in oil, natural gas and other industries, such as refinery hydrogenation device pipeline, natural gas long-distance pipeline station.
Classified by connection method
Butt-welding blind flange: butt-welding connection with pipeline, high quality of welded joints, can withstand high pressure and stress. It is suitable for high pressure and high temperature pipeline system, such as main steam pipeline in electric power industry, import and export pipeline of hydrogenation reactor in petrochemical industry.
Flat Welding Blind Flange: It is connected with the pipeline by flat welding, with simple welding process and low cost. Applicable to low pressure, room temperature piping system, such as general civil building water supply and drainage piping, ventilation and air conditioning piping.
Socket Welding Blind Flange: Insert the pipe into the socket hole of the flange for welding, applicable to small caliber pipeline, can reduce welding deformation and improve welding quality. Commonly used in instrumentation piping, small flow process piping, etc..
Threaded blind flange: connected with the pipeline through threads, easy to install and dismantle. It is suitable for some low-pressure, small-diameter pipeline systems, such as household gas pipelines, laboratory of some small flow pipelines. But it is not suitable to be used in high temperature, high pressure and vibration occasions.