Duplex Stainless Steel Stub Ends , ASTM A815 UNS S31803 Steel Weld Pipe Fittings

ASTM A815 UNS S31803 Duplex Stainless Steel Butt Welding Stub End

Stub end(Lap joint) is a fitting that is used replace welded flanges when the support of a rotating back up flange is required. And It can be supplied in standard and non-standard ANSI dimension that is used for connecting pipes of different diameter.

Stub End Types

Stub end are offered in three different ways, type A, B and 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. In addition, the outer corner radius of the type A can receive the lap joint flange. The inside corner is square. Lap usually has a machined serrated face.

Type B

The type B stub end is used for standard slip on flanges as lap flanges. The lap thickness on these short ends is greater than or equal to the nominal thickness of pipe wall. Also, the outer corner radius of type B is small enough to receive the slip o flange that can be used as a backup flange. The inner corner is square. Lap usually has a machined serrated face.

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. The lap thickness is 75% of the pipe wall. The type C is very short enough to accommodate any backup flange. The lap joint on type C is smooth, and it is not machine.

Stub ends are usually manufactured in two ways, Type A and Type B. They are available in two standard length, long (ANSI) or short pattern (MSS).Sch5s and 10s stub end are usually offered in short lengths, and long lengths are available on special order. Sch 40s stub end are supplied in either short or long lengths.

ASTM A815 Standard

ASTM A815 is the standard specification for Wrought Ferritic, Ferritic/Austenitic, and Martensitic Stainless Steel Piping Fitting. This specification covers two general classes, WP and CR. Class WP fittings are subdivided into four classes:

WP-S, seamless products.

WP-W, welded products.

WP-WX, Pipe fittings which contain welds where all welds have been radiographed.

WP-WU, fittings that contain welds where all welds have been ultrasonically tested.

Product Information

Material (UNS S31803) Chemical Compositions

ASME B16.9 Stub End Dimensions (mm)