Investment Casting Process and After Process for Valve Body

Orifice fitting is used to hold the orifice plate to create different pressure in order to measure the flow rate. As most of valve bodies, they are made by investment casting. Due to complex designs, it is still a challenge for some metal casting factories. The following steps are what we ask our supplier and ourselves to follow.

1. Design or OEM engineering（you provide the sample for massive production）
2. Molding
   1. Mother mold (Aluminum)
   1. Wax pattern
3. Investment casting
   • Chemical composition analysis
   1. Dimension inspection
   1. Visual inspection – MSS-SP 55
   • Heat treatment

• Quality control
  • Mechanical property (Tensile Test& impact test)
  1. Dimensions
  1. Surface quality inspection
     1. According to MSS SP 55 Visual Inspection for casting surface defect such as gas porosity, hot tears, cracks, shrink, sand inclusions, veining,
     1. ASTM E 165 Test Method for Liquid Penetrant Examination if necessary
     • ASTM E 709 Guide for Magnetic Particle Examination if necessary
  1. Inner quality inspection (NDT)
     • Radiography Procedure – ASTM E94
     • Ultrasonic examination – ASTM A609
     • Destructive test for the crucial area of the part

• Machining
• Hydraulic testing – API Spec 598
• Inner quality inspection (NDT) for the crucial area of the part if necessary
  1. Radiography Procedure – ASTM E94
  1. Ultrasonic examination – ASTM A609

7. Assembly
8. Packing & Shipping

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