Stub Ends are fittings used in place of welded Flanges
JAV Forgings & Engineering Private Limited in Faridabad Haryana India discusses Stub Ends are fittings employed in place of welded flanges wherever rotating back up flanges are desired. They are also referred to as Lap Joints and Vanstone flared Laps. JAV Forgings & Engineering Pvt. Ltd. is India’s leading steel forging manufacturer and supplier of a diverse range of products. Our forging product list includes high quality of Flanges, Tube sheets, Rings and Shafts, Spectacle Blinds, Stub ends, Ring-joint gaskets and Self-reinforced nozzles.
A rotating back up flange seats itself against the back surface of the Stub end. Once bolts are added, the clamping action of the bolts presses the rotating back up flange against the back of the Stub end. The gasket surface of the Stub end then presses against a gasket and another gasket surface provides joints like standard flange joints. The seal is formed by the gasket surface of the stub end alone, the flange only provides the clamping pressure on the joint.
A stub end and a lap joint flange can be used together as an alternative way to make a flanged connection than 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), material and 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.
BENEFITS OF LAP JOINT STUB ENDS
The use of stub ends has these two advantages:
- 1. Reduces the overall cost of the flanged joint
- 2. Facilitates the installation of the flange
Stub End Types
Stub ends are available in three different types, named “Type A”, “Type B” and “Type C”:
- 1. 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.
- 2. Stub ends type B are have to be used with standard slip-on flanges.
- 3. 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:
- 1. The short pattern, called MSS-A stub ends
- 2. The long pattern, called ASA-A stub ends (or ANSI length stub end)
Stub End Finish
Stub ends can be ordered with different ends finishing:
- 1. Beveled Ends
- 2. Squared Ends
- 3. Flanged Ends
- 4. Grooved Ends
- 5. Threaded Ends (Male Only)