NXF UNS S20910 XM-19 OD DN15-1200 Thickness SCH10-XXS Special Stainless Steel Butt Welding Fitting Lap Joint Stub End

Our Advantages

1.Raw Material Selection and Pre-treatment: 304/316L stainless steel bars/tubes conforming to ASTM standards are selected. Upon arrival at the factory, spectral composition and mechanical property tests are conducted to ensure material compliance. Subsequently, surface oxide scale and impurities are removed through sandblasting and pickling, completing the raw material pre-treatment.

2.Precision Blanking and Forming: According to product specifications, the raw material is precisely blanked using a CNC sawing machine, and then hot forging, cold heading, or spinning processes are used to integrally form a joint blank with a chuck flange, ensuring structural strength and dimensional accuracy, and avoiding hygiene hazards caused by weld gaps.

3.Machining and Finishing: Precision machining of the inner hole, outer diameter, and chuck end face is performed using CNC lathes and milling machines, strictly controlling dimensional tolerances and coaxiality. Simultaneously, chamfering is performed at the joints to eliminate burrs, preparing for subsequent polishing processes.

4.High-precision polishing of inner and outer walls: First, rough polishing and semi-fine polishing remove machining marks, followed by mirror polishing to control the surface roughness of the inner wall to Ra≤0.4μm (Ra≤0.2μm for pharmaceutical grade), ensuring no unsanitary corners and no media residue, meeting clean transport requirements.

5.Passivation and surface treatment: The polished joint is immersed in a special passivation solution to form a dense oxide protective film on the surface, significantly improving the corrosion resistance of the stainless steel. Degreasing and cleaning are then performed to remove surface oil and chemical residues.

6.Non-destructive testing and quality control: Sealing performance is tested using water pressure/air pressure testing. Eddy current testing and penetrant testing are used to check for internal cracks and defects. Simultaneously, dimensions, roughness, and material are fully re-inspected to ensure the product meets industry standards such as 3A and GMP.

7.Clean packaging and shipping: Final cleaning and drying are completed in a cleanroom. Food-grade dust-free packaging is used for sealing to avoid secondary contamination. Material certificates and test reports are included before shipping.