对焊钢法兰：用于法兰与管子的对口焊接，其结构合理，强度与钢度较大，经得起高温高压及反复弯曲和温度波动，密封性可靠。公称压力为0.25-2.5Mpa的对焊法兰采用凹凸式密封面。      平焊钢法兰：适用于公称压力不超过2.5Mpa的碳素钢管道连接。平焊法兰的密封面可以制成光滑式，凹凸式和榫槽式三种。光滑式平焊法兰的应用量最大，多用于介质条件比较缓和的情况下，如低压非净化压缩空气、低压循环水，它的优点是价格比较便宜。     承插焊法兰：常用于PN≤10.0Mpa,DN≤40的管道中；      松套法兰：松套法兰俗称活套法兰，分焊环活套法兰，翻边活套法兰和对焊活套法兰。常用于介质温度和压力都不高而介质腐蚀性较强的情况。当介质腐蚀性较强时，法兰接触介质的部分(翻边短节)为耐腐蚀的高等级材料如不锈钢等材料，而外部则利用低等材料如碳钢材料的法兰环夹紧它以实现密封；      整体法兰：常常是将法兰与设备、管子、阀门等做成一体，这种型式在设备和阀门上常用。

Butt welding steel flange: suit for flange and pipe welding, its structure is reasonable, the strength and stiffness is bigger, can withstand high temperature and high pressure curve and temperature fluctuation, and repeated the sealing is reliable. The nominal pressure of a 250-2.5 Mpa is used with a concave convex cover. Flat welding steel flange: it is suitable for the carbon steel pipe connection with no more than 2.5 Mpa. The cover of flat welding flange can be made of smooth, concave and mortise type 3 kinds. Smooth type of flat welding flange are the biggest, in the condition of medium is more moderate cases, such as suit low circulating water, the purification of compressed air, and it has the advantage of the price is cheaper. Socket welding flange: used in the pipeline for PN less than 100 Mpa, DN less than 40; Loose flange: the loose flange is commonly known as the live flanged flanged flanged flanged flanged flanged flanged flanged flanged flanged flanged flanged flange. It is often used for low medium temperature and pressure. When strong corrosive medium, part of the flange contact medium (flanging nipple) as the corrosion resistance of high grade materials such as stainless steel materials, while the external use of inferior materials such as carbon steel material of flange ring clamp it in order to realize the seal; Integral flange: often is the flange with equipment, pipe, valve etc., this type is used in equipment and valve.