1. Incoming Raw Material Inspection: Material analysis and visual inspection of raw steel (round bars/forging billets); verification of material grade and heat/batch numbers; rejection of defective materials. 2. Material Cutting: Cutting billets to product specifications while allowing for machining allowances.
3. Heating and Forging: Heating billets to forging temperature and forging into T-shaped tee blanks; forming the general external shape of the main and branch outlets.
4. Heat Treatment: Normalizing or annealing to relieve forging stresses, refine the microstructure, and enhance fitting toughness.
5. Blank Cleaning: Shot blasting or sandblasting to remove oxide scale and forging skin; inspection for surface cracks or folding defects.
6. Machining (Core Process)
Turning of outer diameters and end faces; Drilling and boring of inner bores at the three ports;
Threading (NPT tapered threads or BSP parallel threads);
Machining of weld bevels and chamfers.
7. Dimensional and Thread Inspection: Inspection using calipers and thread gauges; checking inner/outer diameters, thread profiles, and wall thickness.
8. Non-Destructive Testing (NDT): Magnetic particle or liquid penetrant testing to detect internal and surface cracks.
9. Stamping/Marking: Marking material grade, specifications, standards, and heat/batch numbers.
10. Surface Treatment: Anti-rust treatment (black oxide, phosphating, or galvanizing, per customer requirements).
11. Finished Product Inspection: Full inspection of appearance, dimensions, and threads; hydrostatic pressure testing on a sampling basis.
12. Packaging and Warehousing: Packaging in anti-rust bags and cartons/wooden crates; labeling and warehousing.