Buttweld Stub End
Stub End : Specifications | Materials | Types | Dimensions | Weight Chart | Tolerances | FAQ
Top Manufacturer & Global Exporter of ASME B16.9 Buttweld Stub Ends – Offering high-quality stub ends in Stainless Steel, Carbon Steel, Alloy Steel, and High Nickel Alloys, available in both Seamless and Welded types (SCH 40 / SCH 80)
Best Export Prices: sales@midlandforgefittings.com
Midland Forge and Fittings Pvt. Ltd. is a trusted name in the global piping component industry, known for its precision-engineered ASME B16.9 Stub Ends. Manufactured with cutting-edge technology and strict quality control, our stub ends are designed for durability and corrosion resistance. Available in both Seamless (½″ NB to 24″ NB) and Welded (½″ NB to 48″ NB) forms, these fittings are ideal for industries that require reliable disconnection and rotation within piping systems—such as petrochemicals, power plants, and marine applications.
Short Stub Ends (also known as MSS Type A or Type B) are designed for systems where frequent dismantling is required for inspection, cleaning, or maintenance. These fittings are typically used in conjunction with lap joint flanges and are ideal for low-pressure and non-critical applications.
Long Stub Ends are primarily used in high-pressure pipelines and corrosive environments where added reinforcement and strength are needed. These are ideal for use in industries such as oil & gas, petrochemical, marine, and power generation. Manufactured with precision using advanced machinery and strict quality protocols, each long stub end ensures perfect alignment and high resistance.
We have built a solid reputation for supplying top-quality pipe fittings to over 30 countries worldwide. With a strong foothold in major markets such as Germany, Australia, South Africa, and the Middle East, Midland Forge and Fittings Pvt. Ltd. is committed to delivering exceptional value through competitive pricing, prompt delivery, and tailored solutions. Whether you’re sourcing ASME B16.9 buttweld stub ends or other critical fittings, Midland stands as your trusted partner for engineering excellence and long-term reliability.
Stub End Specifications, Sizes & Standards
Stub Ends – Materials, Grades & Standards
| Material Category | Grade | Standards (ASTM / ASME) | Typical Use/Application |
|---|---|---|---|
| Stainless Steel | 304 / 304L / 304H | ASTM A403 WP304/304L/304H | General purpose, corrosion resistance |
| 316 / 316L / 316H | ASTM A403 WP316/316L/316H | Marine & chemical applications | |
| 317 / 317L | ASTM A403 WP317/317L | High corrosion resistance | |
| 321 / 321H | ASTM A403 WP321/321H | High temperature, stabilized | |
| 347 / 347H | ASTM A403 WP347/347H | High-temp pressure systems | |
| 904L | ASTM A403 WP904L / B625 | Acid handling, sulfuric environments | |
| 254 SMO | ASTM A403 / B366 | High chloride environments | |
| Carbon Steel | A234 WPB / WPC | ASTM A234 | Pressure piping & general piping systems |
| A420 WPL6 | ASTM A420 | Low temperature services | |
| Alloy Steel | A234 WP1 / WP5 / WP9 | ASTM A234 | High-temp & pressure pipelines |
| A234 WP11 / WP22 | ASTM A234 | Steam lines & refineries | |
| A234 WP91 | ASTM A234 | Power generation, high performance | |
| Duplex Steel | UNS S31803 / S32205 | ASTM A815 / A790 | Corrosion & high strength use |
| Super Duplex Steel | UNS S32750 / S32760 | ASTM A815 / A790 | Offshore, seawater applications |
| Nickel Alloys | Nickel 200 / 201 | ASTM B366 / B162 | Alkali & chemical processing |
| Inconel 600 / 625 / 718 | ASTM B366 | Heat exchangers, aerospace | |
| Incoloy 800 / 825 | ASTM B366 | Petrochemical & chemical processing | |
| Hastelloy C22 / C276 | ASTM B366 | Severe corrosion resistance | |
| Monel 400 / K500 | ASTM B366 | Seawater, chemical industries | |
| Alloy 20 | ASTM B366 | Sulfuric acid services | |
| Nimonic 75 / 80A | ASTM B366 / B637 | High-temp applications | |
| Copper Nickel | Cu-Ni 90/10 / 70/30 | ASTM B466 / B467 | Marine systems, seawater service |
| Titanium | Grade 2 / Grade 5 | ASTM B363 | Lightweight, corrosion resistance |
| Aluminium | 6061 / 5083 | ASTM B361 | Low-pressure, non-corrosive piping |
Dimensions of Buttweld Stub End
| Nominal Pipe Size (NPS) | OD (mm) | Short Pattern – Lap Length (mm) | Long Pattern – Lap Length (mm) |
|---|---|---|---|
| 1/2″ | 21.3 | 14 | 51 |
| 3/4″ | 26.7 | 16 | 51 |
| 1″ | 33.4 | 18 | 51 |
| 1 1/4″ | 42.2 | 19 | 51 |
| 1 1/2″ | 48.3 | 21 | 57 |
| 2″ | 60.3 | 22 | 64 |
| 2 1/2″ | 73.0 | 25 | 70 |
| 3″ | 88.9 | 27 | 76 |
| 4″ | 114.3 | 32 | 83 |
| 5″ | 141.3 | 35 | 95 |
| 6″ | 168.3 | 38 | 102 |
| 8″ | 219.1 | 41 | 111 |
| 10″ | 273.0 | 44 | 121 |
| 12″ | 323.8 | 48 | 152 |
Weight Chart: ASME B16.9 Stub End (SCH 40 / STD)
| Size (inches) | Short Stub End (kg) | Long Stub End (kg) |
|---|---|---|
| ½″ | 0.15 | 0.25 |
| ¾″ | 0.25 | 0.35 |
| 1″ | 0.35 | 0.50 |
| 1½″ | 0.70 | 1.00 |
| 2″ | 1.10 | 1.60 |
| 3″ | 2.30 | 3.20 |
| 4″ | 3.80 | 5.50 |
| 6″ | 7.00 | 10.50 |
| 8″ | 12.50 | 18.00 |
| 10″ | 19.00 | 27.50 |
| 12″ | 26.00 | 38.00 |
| 14″ | 34.00 | 50.00 |
| 16″ | 42.00 | 62.00 |
| 18″ | 50.00 | 74.00 |
| 20″ | 60.00 | 88.00 |
| 24″ | 78.00 | 115.00 |
Stub End Pipe Fitting Tolerances as per ASME B16.9
| Fitting Type | Parameter | Tolerance | |
|---|---|---|---|
| Up to 4” NPS | Above 4” NPS | ||
| Stub End(Short & Long) | Outside Diameter at Bevel | ±1.6 mm (1/16″) | ±1.6 mm (1/16″) |
| Center-to-End (A, B) | ±1.6 mm (1/16″) | ±3.2 mm (1/8″) | |
| Wall Thickness | -12.5% (no positive tolerance) | ||
| Ovality | Shall not exceed 1% of specified OD | ||
When should we use a long pattern stub end over a short one?
Long Pattern Stub End:
- High-Pressure Systems: The longer hub provides better support and distributes stress over a larger area, reducing the risk of flange or pipe deformation.
- Frequent Disassembly: Systems that require regular maintenance or disassembly benefit from long stub ends because they maintain flange alignment and ensure consistent gasket compression.
- Corrosive or Aggressive Environments: The longer hub offers more surface area for corrosion resistance, and when paired with lap joint flanges, it allows the flange to remain intact while the stub end is replaced.
Short Pattern Stub End:
- Cost-Sensitive Applications: Short stub ends use less material, making them more economical.
- Tight Installations: When space is limited, a short stub end fits easily without requiring extra clearance.
- Low-Pressure Systems: In systems with lower pressure and less frequent disassembly, short stub ends provide sufficient performance.
Are long and short stub ends interchangeable?
No, long and short stub ends are not fully interchangeable. Although both types are designed to work with lap joint flanges and serve the same basic function, the difference in hub length affects how they fit within the piping system. Using a stub end of the wrong length can impact:
- Flange Alignment: Longer or shorter hubs can shift the flange position, leading to misalignment with connected equipment or piping.
- Spacing and Clearance: Pipeline layout may require a specific hub length to maintain proper spacing between components.
- Gasket Compression: Incorrect stub end length can alter gasket compression, potentially compromising the seal.
Are short pattern stub ends compatible with all flange types?
Short pattern stub ends are primarily designed for use with lap joint flanges and, in some cases, slip-on flanges. Compatibility depends on several factors:
- Flange Face Type: The stub end must match the flange face (e.g., raised face, flat face) to ensure proper sealing and gasket compression.
- System Requirements: They are ideal in systems that require frequent dismantling or maintenance, allowing the flange to remain in place while the stub end is replaced.
- Pressure and Temperature Considerations: Short stub ends are suitable for low- to medium-pressure applications, but may not provide adequate support in high-pressure systems compared to long pattern stub ends.