Stub Ends for Flanged Joints

A stud end and alap joint flangecan be used together as an alternative way to make a flanged connectionthan welding neck flanges.

The two devices to be combined, in this case, are:

• The stub end, which is essentially a piece of pipe, with one end flared outwards and the other prepared to be welded to a pipe of the same bore size (NPS = nominal pipe size),materialand wall thickness. The most widely used fabrication tool for stub ends is the flaring machine, which is able to flare the end of the pipe and then cuts it to length.

• A Lap Joint Flange, which is used to actually bolt the two lengths of pipe together.

Stub ends are available in three different types, named “Type A”, “Type B” and “Type C”:

• The first type (A) is manufactured and machined to match standard lap joint backing flange (the two products have to be used in combination). The mating surfaces have an identical profile to permit a smooth loading of the flare face
• Stub ends type B are have to be used with standard slip-on flanges
• Type C stub ends can be used either with lap joint or slip-on flanges and are manufactured from pipes

SHORT/LONG PATTERN STUB ENDS (ASA/MSS)

Stub ends are available in two different patterns:

• the short pattern, called MSS 43 -A stub ends
• the long pattern, called ASA-A stub ends (or ANSI length stub end)

Chemical Composition % of (UNS32750) 2507

ASTM A815 UNS S32750 Pipe Fittings Specification

Equivalent Grades of ASME SA815 Super Duplex Steel Buttweld Fittings