Stub End is a short length of pipe with one flared end and one square-cut end, which is welded to a pipe of the same NPS, material grade and schedule. Stub ends are fittings used in place of welded flanges where rotating back up flanges are desired. They are mainly used with standard Lap Joint Flanges
The stub ends are available in three types –
Type A, Type B and Type C. Type A and B stub end are similar to forged fittings, such as elbows and tees, and type C stub end are made in customized sizes.
Type A –The type A stub end is used for standard lap joint flange. The lap thickness on the stub end is greater than or equal to the nominal thickness of pipe wall.
Type C- The type C stub end can be used for standard lap joint flange and slip on flange. It is flared leaving a rounded edge at the inside diameter of the lap. If necessary, the radius can be made closed to a square.