The long type is unsuitable for pipes and is used in process plant.
[3] A weld neck flange consists of a circular fitting with a protruding rim around the circumference.
Generally machined from a forging, these flanges are typically butt welded to a pipe.
[4] Such flanges are suitable for use in hostile environments that have extremes of temperature, pressure or other sources of stress.
[4] The resilience of this type of flange is achieved by sharing the environmental stress with the pipe with which it is welded.