Welding neck flange is the correct terminology to be used as per Gost 12821--80, ASME B16.5. However in the industry Welding Neck Flanges are commonly refered to as Weld Neck Flange or WN flange. The welding neck flange consists of a tapered hub which is secured to the pipe by a full penetration butt weld. Because of the additional reinforcement area avaliable in the hub of weld neck flange and due to its installation by welding, the hub becomes an integral part of the pipe. This gives a weld neck flange greater strength and integrity and ability to withstand considerably higher bending moments than a slip on flange. Since weld neck flanges are secured to pipe by butt welding, the internal diameter of the hub end should match the internal diameter of the pipe ID or wall thickness are required to be specified for purchasing welding neck flange.
The butt weld permits non-destructive examination by radiography to be carried out on the weld neck flange unlike slip on flange which can be examined only by magnetic particle inspection or dye penetration inspection. The weld neck flange can be directly welded to butt weld fittings like elbows, tees or reducers without requiring any short piece of pipe unlike slip on flange which require a straight length of pipe for installation. Despite the initial procement cost of weld neck flange being higher than a slip on flange, the installation cost which includes welding and inspection reduces the differential. Welding neck flanges can withstand higher bending moments. Welding neck flanges are suitable for piping systems subject to high pressures, high cyclical loading, high temperatures as well as cryogenic services.
The industrial process come into die forging and machining, we can provide a wide range of flanges, following on standards like ASME B16.5 Flange, ASME B16.47 A&B flange, DIN2631 welding neck flange, JIS 5K SOP and 10K SOH Flange. ASME Flange include B16.5, B16.47 A&B flange, this standard system include slip on flange, blind flange, welded neck flange, lapped joint flange ( loose flange), socket welded flange, B16.36 Orifice Flange, long weld neck flange, and Special Flange, size from 1/2 inch to 60 inch, class 150-class 2500.
Contact Now
