Products

Type "C" and "CS" Stub Ends

Stub Ends are fittings used in place of welded flanges where rotating back up flanges are desired. They are also called Lap Joints and Vanstone Flared Laps. A rotating back up flange seats itself against the back surface of the Stub End. When 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 providing joints like standard flange joints. The seal is made by the gasket surface of the stub end alone, the flange only provides the clamping pressure on the joint.

Since Stub Ends are made from material compatible with the designed piping system, back up flanges do not have to be made from the same material. The flange can be made from less expensive material because it never comes in contact with the process fluid.

Stub Ends are typically manufactured by two methods. Type A & B Stub Ends are made similar to forged fittings such as Elbows and Flanges.

Stub Ends are available in two standard lengths, MSS and ANSI and are normally provided with a standard weld bevel. Stub end dimensions are shown below.

Type C Stub End Size Chart

NPSODGMSS FASA FIDTIDT
1/2"0.84"1-3/8"2"3".0674".083".622".109"
3/4"1.050"1-11/16"2"3"0.884".083".0824".113"
1"1.315"2"2"4"1.097".109"1.049".113"
1-1/4"1.660"2-1/2"2"4"1.442".109"1.380".140"
1-1/2"1.900"2-7/8"2"4"1.682".109"1.610".145"
2"2.375"3-5/8"2-1/2"6"2.157".109"2.067".154"
2-1/2"2.875"4-1/8"2-1/2"6"2.635".120"2.469".203"
3"3.500"5"2-1/2"6"3.260".120"3.068".216"
4"4.500"6-3/16"3"6"4.260".120"4.026".237"
5"5.563"7-5/16"3"8"5.295".134"5.047".258"
6"6.625"8-1/2"3-1/2"8"6.357".134"6.065".280"
8"8.625"10-5/8"4"8"8.329".148"7.981".322"
10"10.750"12-3/4"5"10"10.420".165"10.020".365"
12"12.750"15"6"10"12.390".180"12.000".375"

** We also manufacture stub ends with special lap face diameters

Type C Stub End

These Stub Ends are for use with standard Lap Joint Flanges and Slip On Flanges. The Lap of a Type “C” is flared over – leaving a rounded edge at the I.D. of the Lap. If required this radius can be made nearly square. The Lap thickness is 75% of the pipe wall under consideration. The Type “C” has a very short outside fillet radius small enough to accomodate any back up flange. The Lap face on a Type “C” is not machined and is smooth.

Type A Stub Ends

These Stub Ends are for use with standard Lap Joint Flanges.The Lap thickness on these Stub Ends is greater than, or equal to, the minimum thickness of the pipe wall under consideration. The Type “A” has its outside corner radiused to accommodate Lap Joint Flanges. The inside corner is square. The Lap generally has a machined serrated face.

Type B Stub Ends

These Stub Ends are for use with standard Slip-On Flanges acting as Lap Joint Flanges. The Lap thickness on these Stub Ends is greater than, or equal to, the minimum thickness of the pipe wall under consideration. The Type “B” has an outside corner radius small enough to accommodate Slip-On Flanges that are being used as the Backup Flange. The inside corner is square. The Lap generally has a machined serrated face.