Long Weld Neck Standard
Class 600 Long Weld Neck Flanges
MSS SP-97 long weld neck flanges for Class 600 service
Class 600 Long Weld Neck flanges are heavy-duty components for high-pressure vessel nozzles in refining, petrochemical, and power generation service. The substantial hub wall thickness and forged construction provide the strength needed to handle both internal pressure and external piping loads at Class 600 conditions.
At this pressure class, the advantage of a one-piece forged LWN flange over a separate pipe-and-flange assembly becomes most apparent. The elimination of the circumferential butt weld between the pipe and flange removes a potential failure point and reduces the scope of radiographic inspection at each nozzle.
Class 600 LWN flanges are standard components on high-pressure separators, reactor vessels, and heat exchanger channels in hydroprocessing, catalytic reforming, and high-pressure steam service. Ring-type joint faces are commonly specified for maximum sealing reliability.
