Expander
Expander : Specifications | Materials | Dimensions | Weight Chart | Tolerances | FAQ
Renowned Manufacturer & Exporter of ASME B16.9 Buttweld Expanders – Offering Seamless and Welded Pipe Expanders (½” to 24”, SCH 40 / SCH 80) in Stainless, Carbon, and Alloy Steel for Oil & Gas, Petrochemical, and Power Industries across the UAE, Saudi Arabia, Australia, the USA, and Germany.
Best Export Prices: sales@midlandforgefittings.com
Midland Forge and Fittings Pvt. Ltd is a trusted manufacturer and exporter of high-quality Expander Buttweld Fittings, specializing in seamless and welded expanders in stainless steel, carbon steel, alloy steel, and high nickel alloys. With decades of experience, we deliver precision-engineered expanders that meet stringent international standards such as ASME B16.9, ASTM, and ISO.
Committed to excellence, we combine advanced manufacturing techniques, rigorous quality control, and timely delivery to ensure the superior performance of our expanders. Our range includes pipe expanders in various sizes (½” to 24”) and schedules (SCH 40 / SCH 80), designed for seamless integration with Buttweld piping systems. With a strong global presence, we serve clients across multiple countries, providing reliable solutions for critical pipe size transitions.
A Buttweld Expander is a type of pipe fitting designed to increase the diameter of a pipeline at one end while maintaining a smooth flow path. It provides a gradual expansion from a smaller pipe to a larger pipe, typically in a single-ended configuration, unlike reducers which reduce size.
Expanders are manufactured to ASME B16.9 standards and are available in seamless or welded construction. The primary function of an expander is to facilitate a pipe size transition while ensuring minimal turbulence, maintaining system integrity, and allowing proper connection with flanges, valves, or other piping components.
We prioritize the safe handling and delivery of our products, ensuring that every pipe fitting and flange reaches our clients in pristine condition. Each item is carefully inspected, cleaned, and individually packed using high-quality protective materials to prevent corrosion, damage, or contamination during transit.
For bulk orders, we employ customized packaging solutions, including wooden crates, pallets, and steel drums, tailored to the size, weight, and material of the fittings. Our robust packaging is complemented by a streamlined logistics process, ensuring timely shipment and secure delivery to clients across domestic and international markets, including sensitive regions where precision and care are paramount.
expander buttweld fittings - Specifications, Sizes & Standards
pipe expander fittings – 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 ASME B16.9 expander
| Small End NPS (inch) | Large End NPS (inch) | Small End OD (mm) | Large End OD (mm) | Length H (mm) | Schedule / Wall Thickness |
|---|---|---|---|---|---|
| ½” | 1″ | 21.3 | 33.4 | 80 | SCH 40 |
| 1″ | 2″ | 33.4 | 60.3 | 100 | SCH 40 |
| 2″ | 3″ | 60.3 | 88.9 | 120 | SCH 40 / SCH 80 |
| 3″ | 4″ | 88.9 | 114.3 | 140 | SCH 40 / SCH 80 |
| 4″ | 6″ | 114.3 | 168.3 | 160 | SCH 40 / SCH 80 |
| 6″ | 8″ | 168.3 | 219.1 | 200 | SCH 40 / SCH 80 |
| 8″ | 10″ | 219.1 | 273.0 | 220 | SCH 40 / SCH 80 |
| 10″ | 12″ | 273.0 | 323.9 | 250 | SCH 40 / SCH 80 |
| 12″ | 14″ | 323.9 | 355.6 | 280 | SCH 40 / SCH 80 |
| 14″ | 16″ | 355.6 | 406.4 | 300 | SCH 40 / SCH 80 |
| 16″ | 18″ | 406.4 | 457.2 | 320 | SCH 40 / SCH 80 |
| 18″ | 20″ | 457.2 | 508.0 | 340 | SCH 40 / SCH 80 |
| 20″ | 24″ | 508.0 | 609.6 | 380 | SCH 40 / SCH 80 |
Weight Chart: stainless steel expander fitting (SCH 40 / STD)
| NPS (inch) | O.D. Small End (inch) | O.D. Large End (inch) | Schedule | Weight per Piece (lbs) |
|---|---|---|---|---|
| 1/2 | 0.840 | 1.050 | SCH 40 | 0.60 |
| 3/4 | 1.050 | 1.315 | SCH 40 | 0.80 |
| 1 | 1.315 | 1.660 | SCH 40 | 1.20 |
| 1 1/4 | 1.660 | 1.900 | SCH 40 | 1.70 |
| 1 1/2 | 1.900 | 2.375 | SCH 40 | 2.30 |
| 2 | 2.375 | 2.875 | SCH 40 | 3.30 |
| 2 1/2 | 2.875 | 3.500 | SCH 40 | 5.00 |
| 3 | 3.500 | 4.000 | SCH 40 | 6.80 |
| 4 | 4.500 | 5.000 | SCH 40 | 10.50 |
| 6 | 6.625 | 8.000 | SCH 40 | 22.00 |
| 8 | 8.625 | 10.000 | SCH 40 | 36.00 |
| 10 | 10.750 | 12.000 | SCH 40 | 53.00 |
| 12 | 12.750 | 14.000 | SCH 40 | 74.00 |
seamless & welded pipe expander - Tolerances as per ASME B16.9
| Parameter | Tolerance |
|---|---|
| Outside Diameter (OD) | ±1% of nominal OD |
| Wall Thickness | ±12.5% of nominal wall thickness |
| Center-to-End (CTE) / End-to-End (ETE) Length | ±1/16 inch for sizes ≤ 12” ±1/8 inch for sizes > 12” |
| Angle of Bend (Elbows) | ±1° for 45° and 90° elbows ±2° for 180° elbows |
| Concentricity of Reducers | ≤ 5% of difference between large and small end OD |
| Out-of-Roundness | ≤ 1% of OD |
| Surface Finish (Inside / Outside) | As per good commercial practice; smooth, , free from cracks, scale, and roughness |
| Bevel Angle (BW Ends) | 30° ± 5° (typical for welding prep) |
| Squareness of End to Centerline | ±1/8 inch for ≤ 12” ±1/4 inch for > 12” |
What is the difference between a reducer and an expander?
| Feature | Reducer | Expander |
|---|---|---|
| Function | Reduces pipe size from large to small | Increases pipe size from small to large |
| Flow Impact | Can increase velocity, may cause pressure drop | Decreases velocity, may reduce pressure drop |
| Installation | Used where pipe diameter decreases | Used where pipe diameter increases |
How are ASME B16.9 Buttweld Expanders manufactured?
Seamless / Welded Pipe Selection: High-quality pipe material is selected based on size and schedule.
Hot Forming: For seamless expanders, pipe ends are expanded using hydraulic or mechanical methods.
Forging / Welding (if applicable): Larger sizes may require welded fabrication.
Heat Treatment: To relieve stress and achieve proper mechanical properties.
Inspection & Testing: Includes dimensional checks, PMI (Positive Material Identification), NDT (X-ray, UT, or hydrotesting).
How is flow affected by expanders?
Expanding pipe diameter reduces fluid velocity, lowering frictional pressure losses.
Minimizes turbulence compared to sudden diameter jumps.
Helps prevent erosion in sensitive equipment downstream.