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Large Diameter Custom DN1200 Stainless Steel Reducing Butt Weld Tee ASTM A815 S31803

Place of Origin Zhejiang, China
Brand Name WNRLN
Certification ISO 9001:2015, PED 2014/68/EU, NORSOK M-650 Qualified
Model Number LD1200-DSS-TEE
Minimum Order Quantity 1 Piece (custom large diameter)
Price USD 500-5000+ / Piece
Packaging Details Custom steel frame crating with internal bracing for large diameter fittings, seaworthy protection
Delivery Time 25-45 working days for custom large diameter fabrication
Payment Terms T/T,L/C
Supply Ability 500 Pieces per Month
Product Details
Product Name Large Diameter Custom DN1200 Duplex Stainless Steel Reducing Tee Material Grade ASTM A815 Duplex UNS S31803 / 1.4462 (2205)
Maximum Diameter DN1200 (48") Yield Strength ≥450 MPa (2× WP316L)
PREN (Corrosion Resistance) 34-35 Application Desalination, Offshore Water Injection, Chemical Plant, Pulp & Paper
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Large Diameter Reducing Tee

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Custom DN1200 Pipe Tee

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Duplex S31803 Butt Weld Tee

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Product Description
Large Diameter Custom DN1200 Stainless Steel Reducing Butt Weld Tee ASTM A815 S31803
Product Overview

The Large Diameter Custom DN1200 Stainless Steel Reducing Butt Weld Tee is a specialized large-bore pipe fitting manufactured from ASTM A815 Duplex UNS S31803 (2205) stainless steel. This custom-engineered reducing tee with nominal diameter up to DN1200 combines the high strength of duplex microstructure (approximately 50% austenite, 50% ferrite) with excellent corrosion resistance (PREN 34-35), providing approximately twice the yield strength of standard austenitic grades like WP304L and WP316L.

The higher strength enables thinner wall design for the same pressure rating, reducing weight and material cost in large diameter applications. Each large diameter custom stainless steel reducing butt weld tee is engineered to project-specific dimensional requirements including non-standard reducing ratios, custom center-to-end dimensions, and special end preparations. The duplex S31803 material offers outstanding resistance to chloride stress corrosion cracking, pitting, and crevice corrosion, making it ideal for large-bore piping systems in aggressive service environments.

Technical Specifications
Parameter Specification
Material Grade ASTM A815 Duplex UNS S31803 / 1.4462 / F51 / 2205
Maximum Diameter Up to DN1200 (48") for Welded Construction
Type Reducing Tee (Custom Reducing Ratios Available)
Wall Thickness Custom Thickness per Design Calculation (typically SCH10S - SCH40S for Large Diameter)
Microstructure Dual-Phase ~50% Austenite + ~50% Ferrite
Yield Strength ≥450 MPa (65 ksi) - Approximately 2* WP304L/WP316L
PREN 34-35 (Excellent Pitting & Crevice Corrosion Resistance)
Standard ASME B16.9, ASTM A815, MSS SP-43, NORSOK M-650
Manufacturing Process Welded Construction with 100% RT of Longitudinal and Circumferential Seams
Testing Hydrostatic Test, 100% RT, PT, PMI, Ferrite Content Measurement, Impact Test
Key Advantages & Application Fields
  • Weight-Optimized Large Diameter Design: The high yield strength of duplex S31803 enables thinner wall design for large diameter custom DN1200 stainless steel reducing butt weld tee fittings, reducing weight by up to 30-40% compared to equivalent pressure-rated WP316L fittings, which lowers structural support requirements and installation costs.
  • Superior Stress Corrosion Cracking Resistance: The duplex microstructure provides exceptional resistance to chloride stress corrosion cracking (SCC), a critical failure mode for standard austenitic stainless steels in large diameter process piping exposed to chlorides above 60°C.
  • Desalination Plants: Ideal for large-bore seawater intake and brine discharge piping, RO membrane feed lines, and MED evaporator connections in both SWRO and thermal desalination facilities.
  • Offshore Water Injection Systems: Large diameter duplex stainless steel reducing tees serve seawater injection and produced water reinjection manifolds on offshore platforms where weight savings and corrosion resistance are critical.
  • Chemical & Petrochemical Plants: Suitable for large-diameter process piping handling chlorinated hydrocarbons, organic acids, and caustic solutions in chemical manufacturing and petrochemical complexes.
  • Pulp & Paper Industry: Resists corrosive white, green, and black liquors in large-bore pulp mill piping systems including digester blow lines and bleach plant piping.
Frequently Asked Questions
Q: What are the advantages of duplex S31803 over WP316L for large diameter stainless steel reducing tee fittings?
A: The large diameter custom DN1200 stainless steel reducing butt weld tee in duplex S31803 offers four key advantages over WP316L for large-bore applications. First, the yield strength of ≥450 MPa is approximately double that of WP316L (≥170 MPa), enabling thinner wall designs that significantly reduce fitting weight and material cost in large sizes. Second, PREN of 34-35 versus 24-26 for WP316L provides substantially better pitting and crevice corrosion resistance. Third, duplex S31803 is virtually immune to chloride stress corrosion cracking, a critical failure mode for WP316L above 60°C in chloride environments. Fourth, the thermal expansion coefficient of duplex S31803 (~13*10⁻⁶/°C) is closer to carbon steel (~11.7*10⁻⁶/°C) than WP316L (~16*10⁻⁶/°C), reducing thermal stress at dissimilar metal welds in large diameter hybrid piping systems.
Q: How are custom large diameter DN1200 tee fittings manufactured and what quality controls apply?
A: Our large diameter custom DN1200 stainless steel reducing butt weld tee is manufactured through a welded fabrication process using ASTM A815 S31803 duplex stainless steel plate. The process includes CNC plasma or waterjet cutting of plate components to precise dimensions, fit-up and tack welding per qualified WPS/PQR, full-penetration welding using ER2209 duplex filler metal, and 100% volumetric NDT (radiographic testing) of all longitudinal and circumferential weld seams. Post-weld quality controls include dye penetrant testing of all surfaces, PMI verification, ferrite content measurement (targeting 35-65% ferrite per ASTM E562), Charpy V-notch impact testing at design minimum temperature, and hydrostatic pressure testing. The entire process is documented with full traceability from plate heat number to final inspection report, and supervised by certified welding inspectors (CWI) to ASME Section IX and AWS D1.6 requirements.
Q: What dimensional customization options are available for large diameter reducing tees?
A: For our large diameter custom DN1200 stainless steel reducing butt weld tee, we offer extensive customization including: non-standard reducing ratios (e.g., 1200*900, 1200*750, 1200*600 and any intermediate combination); custom center-to-end dimensions (C and M values) to match existing piping layouts; special end preparations including weld neck flange ends, lap joint stub ends, or Van Stone ends; reinforcements including pad-reinforced branch connections for high D/d ratios; and pup piece extensions for direct butt welding to adjacent components. Each custom design is supported by engineering calculations per ASME B31.3 area replacement rules and finite element analysis (FEA) when required for non-standard configurations. We provide detailed manufacturing drawings for customer approval before fabrication begins, ensuring your large diameter custom tee exactly meets project piping isometric requirements.