ASME B16.5 Class 300 flanges have a variety of types and can be classified according to the connection method:welding neck flange,slip on flange，socket welding flange，threaded flange，lap joint flange，blind flange。According to material:carbon steel flange,alloy steel flange,stainless steel flange,duplex stainless steel flange etc.

The EN10253-4 stainless steel butt welded pipe standard includes more than 20 European standard stainless steel materials, including X2CrNi18-9（1.4307）、X2CrNi19-11（1.4306）、X2CrNiN18-10（1.4311）、X5CrNi18-10（1.4301）、X6CrNiTi18-10（1.4541）、X6CrNiNb18-10（1.4550）、X1CrNi25-21（1.4335）、X2CrNiMo17-12-2（1.4404）。Stainless steel material.The following is a table of chemical composition and mechanical performance parameters for each material grade.

ASTM A335 is a common material for American standard alloy steel seamless pipes, which are widely used industry such as petroleum, chemical, power, and nuclear energy. It's material contains alloy elements such as Cr, Ni, and Mo, which can improve the high-temperature and high-pressure resistance, corrosion resistance, and mechanical properties of steel pipes. It can be widely used in complex pipeline environments with high temperature and pressure.

ASTM A106 seamless steel pipe outer diameter size range from 1/8 inch to 48 inches.The length of seamless steel pipes is divided into fixed length and loose length, with fixed length generally being 5.8 meters or 6 meters, 11.8 meters or 12 meters per unit length.

As can be seen from the above picture, the EN 1092-1 TYPE11 flange is a weld neck flange. Weld-neck flange is a type of flange pipe with a neck and a circular steel pipe connection, which is connected to the pipe end by butt welding. Weld neck flanges are not easy to deform and are used in conjunction with bolts and gaskets.

EN1092-1 flanges are a European standard flange that specifies requirements for the dimensions, types, materials, and manufacturing of flanges under different pressure levels. This standard ensures the interchangeability and compatibility of flanges, allowing pipe fittings produced by different manufacturers to be smoothly connected.