High Quality SS Buttweld Pipe Fittings

309/310/310S • Strength • Sealing • Durability

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Premium Stainless Steel 309/310/310S Buttweld Pipe Fittings by Ratnadeep Steel & Engg. Co.

Ratnadeep Steel & Engg. Co. is a leading manufacturer, exporter, and supplier of premium-quality Stainless Steel 309 / 310 / 310S Buttweld Pipe Fittings. These fittings are manufactured from high-alloy austenitic stainless steels with high chromium and nickel content, using advanced production techniques to ensure excellent mechanical strength, dimensional accuracy, and long-term reliability. Our SS 309, 310, and 310S buttweld fittings are widely used in high-temperature and corrosive environments where superior oxidation resistance and structural stability are critical.

Stainless Steel 309, 310, and 310S grades are specifically designed for elevated-temperature applications and offer exceptional resistance to scaling and oxidation. Their buttweld pipe fittings feature precision-beveled ends that allow full-penetration welding, resulting in strong, leak-proof, and permanent joints. These fittings provide a smooth and continuous internal surface throughout the piping system, minimizing flow turbulence, reducing pressure drop, and enhancing resistance to corrosion, erosion, and thermal fatigue under severe operating conditions.

  • Stainless Steel 309 90° Elbow
  • ASTM A403 SS 310 45° Elbow
  • UNS S31000, S31008 180° Elbow
  • UNS S30900 LR Elbow
  • DIN 1.4841 SR Elbow
  • ANSI B16.9 SS 310S 90° Short Radius Elbow
  • 310S SS 45° Long Radius Elbow
  • SS ASTM A403 WP309 Equal Tee
  • ASME B16.9 Stainless Steel 310S Pipe Tee
  • DIN 1.4833 Butt weld Tee
  • ASME SA403 Stainless Steel 310 Reducing Tee
  • DIN 1.4833 Unequal Tee
  • UNS S30900 / S31000 / S31008 Tees
  • A403 WP 310 SS Straight Tee
  • B16.9 Stainless Steel 309 Eccentric Reducer Supplier
  • ASTM A403 Stainless Steel WP310 Eccentric Reducer
  • ASTM A403 WP310S SS Eccentric Reducer
  • UNS S31000 | S31008 Eccentric Reducers
  • DIN 1.4845 Eccentric Reducer
  • ANSI B16.9 Stainless Steel 309 Concentric Reducer Supplier
  • SS ASME SA 403 WP310 Concentric Reducer
  • Stainless Steel 310S Concentric Reducer
  • UNS S31000, S31008 Concentric Reducers
  • SS DIN 1.4833 / 1.4841 Concentric Reducer
  • ASTM A403 WP309 SS Long Stub End Supplier
  • ASME B16.9 Stainless Steel 310 Long Stub Ends
  • UNS S30900 / S31000 / S31008 Long Stub End
  • SS 310S Long Stub End
  • SS 309 / 310 Lap Joint Stub End
  • DIN 1.4833 / 1.4841 Long Stub End
  • ASTM A403 SS 309 Short Stub End Supplier
  • ASME B16.9 Stainless Steel A403 WP 310S Short Stub Ends
  • ASME SA 403 Stainless Steel 310S Short Stub End
  • SS UNS S30900 Short Stub Ends
  • DIN 1.4841 Short Stub End
  • ASTM A403 / SA403 Stainless Steel WP309 Pipe Cap Supplier
  • ASME B16.9 SS 310 End Pipe Cap
  • SS UNS S30900 Pipe End Cap
  • UNS S31000 Buttweld Cap
  • DIN 1.4845 Cap
  • A403 WP 310S Buttweld Pipe Cap
  • UNS S31008 End Cap
  • ASTM A403 Stainless Steel 309 Equal Cross
  • ASME B16.9 SS 310 Buttweld Cross
  • ASTM A403 WP310S Cross
  • SS UNS S30900 / S31000 Unequal Cross
  • SS S31008 Cross
  • DIN 1.4833 Reducing Cross
  • ASME SA 403 SS 309 Pipe Bend Exporter
  • B16.9 Stainless Steel 310 Piggable Bend
  • UNS S30900 / S31000 / S31008 U Bend
  • SS DIN 1.4841 Long Radius Bend
  • ASTM A403 Stainless Steel 310S Buttweld Bend

CHEMICAL COMPOSITION OF SS 309/310/310S SEAMLESS AND WELDED PIPE FITTINGS

Element SS 309 SS 310 SS 310S
Ni 14 max 19 – 22 19 – 22
Cr 23 max 24 – 26 24 – 26
C 0.20 max 0.25 max 0.08 max
Fe 60 max Balance
Mn 2 max 2 max 2 max
Si 1 max 1.50 max 1.50 max
S 0.030 max 0.03 max 0.03 max
P 0.045 max 0.045 max 0.045 max

MECHANICAL PROPERTIES OF ASME SA403 SS WP309 / 310/ 310S BUTTWELD PIPE FITTINGS

Element SS 309 SS 310 SS 310S
Tensile Strength Psi – 89900, MPa – 620 Psi – 75000, MPa – 515 Psi – 75000, MPa – 515
Yield Strength (0.2%Offset) Psi – 45000, MPa – 310 Psi – 30000, MPa – 205 Psi – 30000, MPa – 205
Elongation 45 % 35 % 35 %

SPECIFICATION OF SS 309/310/310S BUTTWELD FITTINGS

Specifications ASTM A403 / ASME SA403
Dimensions ASME/ANSI B16.9, ASME B16.28, MSS-SP-43, BS4504, BS4504, BS1560, BS10 ASME 16.11, MSS SP-79, 83, 95, 97, BS 3799
Size Seamless Butt Weld Fittings: ½” – 10″ | Welded Butt Weld Fittings: ½” – 48″
Schedule SCH10, SCH20, SCH30, STD SCH40, SCH60, XS, SCH 80, SCH 100, SCH 120, SCH 140, SCH 160, XXS available with NACE MR 01-75
Bending Radius R=1D, 2D, 3D, 5D, 6D, 8D, 10D or Custom
Type Seamless / ERW / Welded / Fabricated
Thickness 20 Swg., 18 Swg., 16 Swg., 14 Swg., 12 Swg., 10 Swg., & Sch. 10, Sch. 40, Sch. 80 etc.

309/310/310S STAINLESS STEEL ASTM A403 BUTTWELD FITTINGS EQUIVALENT GRADES

STANDARD UNS WNR. AFNOR EN JIS BS GOST
SS 309 S30900 1.4833
SS 310 S31000 1.4841 X2CrNi18-9/X2CrNi19-11 SUS 310 310524 20Ch25N20S2
SS 310S S31008 1.4845 X8CrNi25-21 SUS 310S 310516 20Ch23N18

PHYSICAL PROPERTIES OF ASTM A403 STAINLESS STEEL 309/310/310S PIPE FITTINGS

Property SS 309 SS 310 SS 310S
Density 8.0 g/cm³ 8.0 g/cm³ 8.0 g/cm³
Melting Point 1455 °C (2650 °F) 1454 °C (2650 °F) 1454 °C (2650 °F)

💡 Practical Difference in Use

Use Stainless Steel 309 / 310 / 310S Buttweld Pipe Fittings when: continuous or intermittent high-temperature service, excellent oxidation resistance, and superior strength at elevated temperatures are required in aggressive thermal environments. → Example: furnace piping, heat treatment equipment, thermal processing lines, and high-temperature petrochemical systems.

Applications of SS 309 / 310 / 310S Buttweld Pipe Fittings

Stainless Steel 309, 310, and 310S Buttweld Pipe Fittings are engineered for extreme heat and oxidation resistance, making them ideal for demanding high-temperature industrial piping applications.

  • Heat Treatment & Furnaces: Radiant tubes, burner lines, and high-temperature gas piping.
  • Petrochemical & Refining: Cracking units, reformers, and hot process fluid lines.
  • Power Generation: Boiler internals, superheater connections, and exhaust piping.

When to Choose SS 309 / 310 / 310S?

These grades are selected for applications requiring exceptional resistance to oxidation, scaling, and thermal fatigue at elevated temperatures, along with strong and reliable welded joints.

Choose SS 309 / 310 / 310S when:

  • Service temperatures exceed the limits of SS 304/304L
  • Outstanding oxidation and scaling resistance is critical
  • Strong, leak-proof welds are required under thermal cycling
  • High chromium and nickel content is needed for heat resistance
  • Used in furnaces, thermal reactors, and high-temperature pipelines

Industries That Use SS 309 / 310 / 310S Buttweld Pipe Fittings

These fittings are widely used in industries where extreme temperatures, oxidation resistance, and structural integrity are essential.

Heat Treatment & Furnace Industry

Designed for components exposed to continuous high temperatures.

Uses

Radiant tubes, burner assemblies, and hot gas piping systems.

Why SS 309 / 310 / 310S?

Exceptional resistance to oxidation, scaling, and thermal degradation.

Petrochemical & Refining

Used in severe high-temperature and corrosive process environments.

Uses

Reformer units, cracking furnaces, and hot process transfer lines.

Why SS 309 / 310 / 310S?

High chromium-nickel content ensures strength and stability at elevated temperatures.

Power Generation

Essential for high-heat and exhaust system applications.

Uses

Boiler internals, superheater connections, and flue gas piping.

Why SS 309 / 310 / 310S?

Excellent heat resistance, weldability, and long service life under thermal stress.

Usage guide for SS 309/310/310S Buttweld Pipe Fittings

When to use SS 309/310/310S Elbow

Smooth directional change in high-temperature pipelines.

Choose Elbow when

  • 45°, 90°, or 180° direction change is required
  • High-temperature resistance is critical
  • Used in furnace, heat exchanger, or chemical lines
  • Corrosion and oxidation resistance is needed
When to use SS 309/310/310S Tee

Creates branch connections in high-temperature pipelines.

Choose Tee when

  • Equal or unequal branching is required
  • High flow distribution efficiency is needed
  • Used in thermal, chemical, or pressure systems
  • Leak-proof welded joints are essential
When to use SS 309/310/310S Eccentric Reducer

Maintains top or bottom alignment in high-temperature pipelines.

Choose Eccentric Reducer when

  • Avoiding air pockets is critical
  • Pump suction lines or boiler feed lines are involved
  • Horizontal piping systems are used
  • Flow disturbance must be minimized
When to use SS 309/310/310S Concentric Reducer

Uniform transition between different pipe diameters in high-temp lines.

Choose Concentric Reducer when

  • Centered pipe alignment is required
  • Vertical piping systems are used
  • Smooth flow reduction is needed
  • Used in furnace, boiler, or heat exchanger discharge lines
When to use SS 309/310/310S Long Stub End

Used with lap joint flanges for easy dismantling in high-temperature systems.

Choose Long Stub End when

  • Frequent dismantling is required
  • Cost-effective flange solutions are needed
  • Corrosion-prone, high-temp environments exist
  • Low-pressure or thermal systems are used
When to use SS 309/310/310S Short Stub End

Compact and economical lap joint connection for high-temperature applications.

Choose Short Stub End when

  • Space constraints exist
  • Economical flange connections are needed
  • Used in chemical or thermal lines
  • Clean, corrosion and oxidation-resistant materials are required
When to use SS 309/310/310S Cap

Seals the end of high-temperature pipelines securely.

Choose Pipe Cap when

  • Pipe ends must be closed
  • Used for pressure testing or isolation
  • Leak-proof sealing is essential
  • High-temperature corrosion resistance is required
When to use SS 309/310/310S Cross

Four-way branch connection for complex high-temperature systems.

Choose Cross when

  • Flow must be split in multiple directions
  • Used in chemical, thermal, or power systems
  • High-strength welded joints are required
  • Long-term corrosion and oxidation resistance is needed
When to use SS 309/310/310S Pipe Bend

Large-radius directional change for smooth high-temperature flow.

Choose Pipe Bend when

  • Gradual direction change is required
  • Used in refineries, boilers, and high-temp pipelines
  • Turbulence and pressure loss must be low
  • Durable, corrosion and oxidation-resistant flow paths are needed

Our Buttweld Pipe Fittings are manufactured using advanced processes and undergo extensive quality checks to ensure flawless weldability, durability, and long service life. Each fitting is thoroughly inspected using key NDT techniques such as radiographic testing (RT), ultrasonic testing (UT), hydrostatic testing, and visual/dimensional examination. We also perform detailed chemical composition analysis and mechanical property testing to ensure material compliance with strict industry standards.

Throughout the forming and welding stages, every buttweld fitting is monitored closely to eliminate defects such as misalignment, surface irregularities, and wall-thickness variations. This ensures perfect joint integrity and high-performance reliability in pipelines carrying high temperatures, pressures, and corrosive media. All our buttweld fittings fully comply with ASME, ASTM, MSS-SP, and related global specifications, making them a preferred choice for critical piping systems worldwide.

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