- Materials- Carbon Steel (ASTM A 105 and A 181), Stainless Steel (ASTM A 182 and A 240), Alloy Steel (ASTM A 182 and GR F1, F11, F22, F5, F9, F91).
- Grade- Super Duplex stainless steel UNS S32750, F 304, 304L, 304H, 317, 347, 347H, , 316, 316L, 316Ti, 904L, Duplex stainless steel UNS S31803.
- Nickel Alloys- Monel 400 & 500, Inconel 600 & 625, Incolloy 800, 825, Hastelloy C22, C276.
- Copper Alloys- Copper, Brass & Gunmetal.
- Size- 1/8″ NB TO 48″NB.
- Class- 900#, 1500# & 2500#, ANSI B16.5 Class 150, ANSI B16.5 Class 300, ANSI B16.5 Class 600, ANSI B16.5 Class 900, ANSI B16.5 Class 1500, ANSI B16.5 Class 2500.
- Standard- ANSI, ANSI B16.5, ANSI B16.47, DIN2566, DIN2573, DIN2642, DIN2655, DIN2576, DIN2641, DIN2632, DIN2633, DIN2634, DIN2635, DIN2628, DIN2629, DIN2638, DIN2673
Normally, manufacturing of weld neck flanges is in various pressure ratings. As a matter of fact, each class of weld neck flange handles more pressure than previous class of its construction. Strangely enough, higher the class is, thicker the metal which leads to a good handling of huge pressures. The pressure capacity of flanges alters when various factors such as the type of metal used and others. Ironically, as the pressure reduces, the temperature increases and is thus vice-versa. To identify flanges, a tough stamp of flange specification is imprint on the outer diameter of the base flange. However, the standard and arithmetical average roughness height (AARH) determines the flange face finish. Above all, there are five types of flange finishes which are as below.
- Cold water – this is done with a wide tool at faster speed which gives mirror like finishing surface or ground surface. It has a mirror like finish. The flange surfaces which have such type of finish are useful in metal to metal applications and not in gasket. They are also useful in oil, chemical and other industries.
- Concentric serrated –to make the grove; a 90 degree align angle tool makes a grove of 0.4 mm deep and 0.2 mm apart in concentric circle.
- Smooth – This is made in various types of tool shapes and has roughness of finish from 5 to 10 micro millimeters.
- Spiral serrated – much similar like stock finish, the only difference is the method of making grove. The same 90 degree incline angle tool is useful to make a grove 0.4 mm deep and 0.2 mm distance.
- Stock – This kind of surface is made using a continuous spiral groove which has a roughness of the finish range from 5 to 20 micro millimeters. This is further cut with a tool having approximately 1.5 mm or larger radius.
Flanges which are often bought into use, have a soft gasket squeeze in between the harder flange surfaces which forms a leak-free seal. Materials used for gasket can be rubbers, elastomers (springy polymers), soft metal (copper or aluminum) and soft polymers covering a springy metal (e.g., PTFE covered stainless steel).
- Most common type of high pressure flange
- Long tapered butt weld hub
- The inside diameter of flange matches the inside diameter of the pipe used
- Preferred in an environment with extreme temperature conditions