NXF UNS S20910 XM-19 OD DN15-1200 Thickness SCH10-XXS Special Stainless Steel Fitting Butt Welding Latrolet/Elbolet

1. Raw Material Incoming Quality Control and Traceability- Core Process: Certified forged steel billets/bars (carbon steel ASTM A105, stainless steel ASTM A182 F304/F316L, alloy steel, duplex steel, nickel alloys, etc.) are used, perfectly matching the material grade of the connected pipes.- Quality Control Focus: 100% verification of factory inspection certificates (MTC), spectrometer material verification, hardness testing, and surface defect inspection. Each batch is assigned a unique heat number for full-process traceability.

2. Precision Blanking and Pre-forming- Core Process: Precise billet weight and dimensions are calculated based on 3D product drawings, and CNC sawing is used to cut individual steel billets. Oxide scale is removed, and pre-upsetting is performed to optimize the metal flow path, while allowing machining allowances for special structures such as bends/elbows.- Quality Control Focus: Strict control of billet weight and dimensional tolerances, especially for bends, allowing sufficient curvature machining allowances.

3. Integral Hot Forging (Core Forming Process)- Core Machining: The billet is heated to the standard forging temperature range using medium-frequency induction heating. Then, using a custom-made precision die, closed-die forging is performed by a CNC hydraulic press to form a seamless, one-piece self-reinforcing structure.- Side Bending: A custom-made die with a fixed 45° branch angle is used to form an integral lateral structure in a single forging.- Bending: A special die matching the curvature of standard 90°/45° long radius (LR)/short radius (SR) bends is used to form the arc-shaped saddle base profile.- Quality Control Focus: Continuous and complete metal production line, free from forging defects (cracks, creases, underfill). Strict control over the 45° angle tolerance of the bend and the profile of the bend saddle base.

4. Standard Heat Treatment- Core Process: Eliminate residual forging stress and optimize metallographic structure and mechanical properties through standard heat treatment processes:- Carbon Steel: Normalizing + Tempering- Stainless Steel: Solution Annealing- Alloy Steel: Quenching + Tempering- Quality Control Focus: Batch hardness testing and mechanical property verification, with complete heat treatment records maintained.

5. CNC Precision Machining (Key Dimension Control Process)- Core Process: Two-step roughing and finishing processes using CNC lathes and five-axis machining centers, strictly adhering to the dimensional tolerances of the butt weld ends according to ASME B16.9 standard.- General Machining: Precision machining of branch pipe butt weld bevels conforming to ASME B16.9 standard, ensuring perfect matching with the outer diameter and wall thickness of the connecting pipe; all surfaces are finished, and sharp edges are chamfered.- Latrolet Exclusive Control: Strict control over the tolerance of the 45° branch angle and the coaxiality of the branch ends, ensuring precise alignment on site.- Elbolet Exclusive Control: Utilizing five-axis simultaneous machining, the 3D curved saddle base is perfectly matched 1:1 to the outer diameter and curvature of the main unit's bending pipe, ensuring a zero-clearance fit with the pipe's outer wall.- Quality Control Focus: 100% dimensional inspection of key parameters, especially the branch angle of the Latrolet and the curvature of the Elbolet's saddle.

6. 100% Non-Destructive Testing (NDT)- Core Processes: Comprehensive testing according to ASTM standards, with a focus on stress concentration areas (Latrolele steel pipe 45° transition zone, Elborough steel pipe saddle base transition zone):- Visual Inspection (VT): Comprehensive inspection for surface defects- Magnetic Particle Testing (MT): Used for carbon steel products, detecting surface and near-surface defects- Penetrant Testing (PT): Used for stainless steel and non-magnetic alloy products- Ultrasonic Testing (UT): Used to detect internal defects in thick-walled and high-pressure (Class 600 and above) products- Quality Control Focus: No non-conforming defects are permitted upon delivery.

7. Surface Treatment- Carbon Steel: Sandblasting to Sa2.5 grade + rust-preventive oil/coating; Hot-dip galvanizing (HDG) for high corrosion resistance requirements- Stainless Steel: Pickling and passivation; Mechanical/electrolytic polishing for sanitary applications

8. Permanent Traceability MarkingLaser marking or low-stress stamping on non-welded surfaces. Standard marking includes: nominal size (pipe section × branch section), pressure rating, material grade, furnace number, manufacturing standard, 45° marking (for pipe fittings), and matching elbow specifications (for elbows).