C. The internal parts with no need for overlaying sealing surfaces
The manufacturing process of the internal parts with no need for overlaying sealing surfaces consists of the following steps: procurement of raw materials (according to the standard), the factory inspection (according to the standard, manufacturing of blanks (the round steel or the forge piece, according to the technological requirements of the drawing), rough machining of the ultrasonic testing surface (according to the pattern) and finish machining.
The Third Step: The Manufacturing Process of the Fastener
The Standard of Fastener Manufacturing: DL439-1991
The manufacturing process of the fastener consists of the following steps: procurement of raw materials (according to the standard), the factory inspection (according to the standard), manufacturing of blanks (the round steel or the forge piece, according to the technological requirements of the drawing), necessary inspection of some samples, rough machining, finish machining and spectrum inspection.
The Fourth Step: Final Assembly
The final assembly consists of the following steps: getting the parts, clearing up and cleaning the parts, having rough assembly (according to the pattern), having hydraulic tests for the valve (according to the drawing and technology), dismantling and cleaning the valve after the test, having final assembly, adjusting the
valve, shipment and delivery.
The Fifth Step: Processes of the Product Production and Inspection
1. Companies purchase raw materials of various specifications.
2. Use the spectrum analyzer to test raw materials and print the analysis report of raw materials for back-up.
3. Use blanking machines to cut raw materials.
4. Inspection personnel inspect the cutting diameter and length of raw materials.
5. Forge and mold raw materials in the forging workshops.
6. Inspection personnel inspect the sizes of blanks for molding.
7. Workers remove waste edges of blanks.
8. Sanding workers process the surface of blanks by the sand blasting process.
9. Inspection personnel inspect the surface after the sand blasting surface treatment.
10. Process the valve's sealing screws. Inspection personnel inspect the processed products.
11. Process the valve's connecting screws.
12. Process mesopores.
13. Inspectors carry out the general inspection.
14. Qualified semi-finished products are sent to the warehouse of semi-finished products.
15. Electroplate semi-finished products.
16. Inspect the electroplated surfaces of semi-finished products.
17. Inspect various parts such as balls, valve stems, sealing valve seats, etc.
Assemble products in the assembly shops. Inspection personnel of the assembly line inspect the valve products.
18. Assembled products are sent to the next procedure after stress tests and drying processes.
19. Pack valve products in assembly shops. Inspection personnel of the packing line inspect tightness, appearance and torsion of valves.
20. Qualified valve products are packed and sent to the finished product warehouse.
21. All inspection records will be classified and stored up in the computer for the inquiry at any time.
22. Qualified valve products are sent home and abroad by containers.
