ASTM A815 UNS S31803 Duplex Stainless Steel Butt Weld Equal Tee is a wrought duplex stainless steel pipe fitting designed for equal-size branch connections in industrial piping systems. This equal tee has three openings with the same nominal diameter and is designed for butt welding to compatible pipes and fittings. Manufactured from UNS S31803 duplex stainless steel, it combines an austenitic-ferritic microstructure with high mechanical strength and good resistance to localized corrosion.

The fitting is manufactured according to ASTM A815 requirements, with applicable dimensions based on ASME B16.9. Different sizes, wall thicknesses, schedules, surface conditions and inspection requirements can be supplied according to project specifications.

UNS S31803 is a duplex stainless steel grade containing both austenitic and ferritic phases. Its alloy system includes chromium, nickel, molybdenum and nitrogen. The duplex microstructure provides a combination of mechanical strength and corrosion resistance, making UNS S31803 suitable for selected industrial piping applications where both properties are important.

UNS S31803 is commonly associated with the Duplex 2205 material family. However, UNS S31803 and UNS S32205 have different specified chemical composition requirements, so the exact grade should always be confirmed against the applicable material standard and Material Test Certificate.

• ASTM A815 covers wrought ferritic, ferritic/austenitic and martensitic stainless steel piping fittings.
• For UNS S31803, the corresponding fitting designation is WP S31803.
• ASTM A815 defines applicable material and manufacturing requirements for wrought stainless steel piping fittings. For this product, ASME B16.9 can be used as the dimensional reference for factory-made butt welding fittings.

ASME B16.9 provides dimensional requirements for factory-made wrought butt welding fittings. An equal tee has three openings with the same nominal diameter and is used to create an equal-size branch connection in a piping system.

Typical configurations include:

• 2" × 2" × 2" Equal Tee
• 3" × 3" × 3" Equal Tee
• 4" × 4" × 4" Equal Tee
• 6" × 6" × 6" Equal Tee
• 8" × 8" × 8" Equal Tee

The exact dimensions, wall thickness and end preparation are determined according to the applicable standard, nominal size and project requirements.

The manufacturing process of ASTM A815 UNS S31803 duplex stainless steel equal tees may include:

1. Raw material selection
2. Material cutting and preparation
3. Forming
4. Solution heat treatment
5. Sizing and dimensional correction
6. End beveling
7. Surface treatment
8. Dimensional inspection
9. Chemical and mechanical testing
10. Final inspection
11. Marking and traceability
12. Packing for shipment

The specific manufacturing route may vary according to fitting size, wall thickness, production method and applicable specification.

ASTM A815 UNS S31803 equal tees can be supplied in different nominal sizes and wall thicknesses according to project requirements.

Common Wall Thickness Schedules:

• SCH 10S
• SCH 20
• SCH 40
• STD
• SCH 80
• XS
• SCH 160
• XXS

Special sizes and wall thicknesses can be reviewed according to engineering drawings, piping class and technical specifications.

Inspection and testing can be performed according to ASTM A815, applicable dimensional requirements, purchase orders and project specifications.

Available inspection items may include:

• Chemical Composition Analysis
• Mechanical Property Testing
• Hardness Testing
• Dimensional Inspection
• Visual Inspection
• Surface Inspection
• Heat Treatment Records
• Positive Material Identification (PMI), when specified
• Non-Destructive Testing (NDT), when required
• Material Traceability
• Material Test Certificate
• EN 10204 3.1 Certificate

• Duplex Stainless Steel Construction: UNS S31803 provides an austenitic-ferritic duplex microstructure and is commonly selected for applications requiring a combination of mechanical strength and corrosion resistance.
• Equal Branch Configuration: The three openings have the same nominal diameter, making the fitting suitable for equal-size branch connections.
• Butt Weld Connection: The butt weld ends are prepared for welding to compatible piping components and can be integrated into fabricated piping systems.
• ASTM A815 Material Specification: The fitting is manufactured according to the applicable ASTM A815 requirements for wrought stainless steel piping fittings.
• ASME B16.9 Dimensions: Applicable dimensions can be supplied according to ASME B16.9 requirements for factory-made butt welding fittings.
• Multiple Size and Schedule Options: Different nominal sizes and wall thicknesses can be supplied according to piping class, engineering drawings and purchase requirements.
• Project-Specific Inspection: Chemical analysis, mechanical testing, dimensional inspection, PMI, NDT and material certification can be arranged according to applicable project requirements.

• Oil and Gas Piping: UNS S31803 duplex stainless steel equal tees can be specified for oil and gas piping systems where duplex stainless steel is required according to service conditions and engineering specifications.
• Chemical Process Piping: The fitting can be used in selected chemical processing systems where material compatibility and resistance to localized corrosion are important considerations.
• Offshore and Marine Piping: Duplex stainless steel pipe fittings can be specified for selected offshore and marine piping systems where mechanical strength and corrosion resistance are required by the project design.
• Desalination and Water Treatment: S31803 duplex stainless steel fittings can be used in selected water treatment and desalination systems where chloride-containing environments require suitable corrosion-resistant materials.
• Industrial Process Piping: The equal tee is suitable for branch connections in industrial process piping, utility systems and other engineered piping applications.

Each ASTM A815 UNS S31803 Duplex Stainless Steel Equal Tee can be supplied with documentation according to the agreed purchase and inspection requirements. Available documentation may include:

• Material Test Certificate
• EN 10204 3.1 Certificate
• Chemical Analysis Report
• Mechanical Test Report
• Heat Treatment Record
• Dimensional Inspection Report
• PMI Report
• NDT Report, when required
• Packing List
• Certificate of Conformity

Material identification and traceability can be maintained throughout the applicable manufacturing and inspection process.