Lap joint stub end is generally a section of the lap joint flange.The stub end of the stainless steel is matched with the carbon steel flange to form a lap joint flange.Lap joint flanges are often used when the medium temperature and pressure are not high and the medium is corrosive.When the medium is highly corrosive,the part of the flange that contacts the medium(the stub end) is a corrosion-resistant high-grade material such as stainless steel,and the outside is clamped with a flanged ring of a low-grade material such as carbon steel to achieve the seal.
ASME B16.9 A403 lap joint stub ends finished in Haihao Group
There are two types of stub end:long stub end and short stub end,and the manufacturing standards usually include MSS SP-43 and ASME B16.9.Whether in the ASME B16.9 standard or in the MSS SP-43,the main difference between long stub end and short stub end is the total length.Take the ASME B16.9 standard as an example.Please see the following stub end drawings and their corresponding dimensions.
ASME B16.9 lap joint stub end drawing
| Norminal Pipe Size
NPS |
Otside Dimension of Barrel | Long pattern length(F) | Short pattern length(F) | Radius of Filler R | Diameter of Lap(G) | |
| Max | Min | |||||
| 1/2″ | 0.896 | 0.809 | 3 | 2 | 0.12 | 1.38 |
| 3/4″ | 1.106 | 1.019 | 3 | 2 | 0.12 | 1.69 |
| 1″ | 1.376 | 1.284 | 4 | 2 | 0.12 | 2 |
| 1-1/4″ | 1.716 | 1.629 | 4 | 2 | 0.19 | 2.5 |
| 1-1/2″ | 1.965 | 1.869 | 4 | 2 | 0.25 | 2.88 |
| 2″ | 2.456 | 2.344 | 6 | 2.5 | 0.31 | 3.62 |
| 2-1/2″ | 2.966 | 2.844 | 6 | 2.5 | 0.31 | 4.12 |
| 3″ | 3.596 | 3.469 | 6 | 2.5 | 0.38 | 5 |
| 3-1/2″ | 4.096 | 3.969 | 6 | 3 | 0.38 | 5.5 |
| 4″ | 4.593 | 4.469 | 6 | 3 | 0.44 | 6.19 |
| 5″ | 5.683 | 5.532 | 6 | 3 | 0.44 | 7.3 |
| 6″ | 6.743 | 6.594 | 8 | 3.5 | 0.5 | 8.5 |
| 8″ | 8.743 | 8.594 | 8 | 4 | 0.5 | 10.62 |
| 10″ | 10.913 | 10.719 | 8 | 5 | 0.5 | 12.75 |
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