用于垫圈连接的设计系数
DESIGN FACTORS FOR GASKET JOINTS

• 在负载期间，全封闭外科使得垫圈能够保持正轴向支撑。
  Full enclosure to allow gasket to retain positive radial support during loading.
• 通过密封环槽的精密公差和径向膨胀的修正来进行压缩的精确调整控制。
  Accurate control of compression through close tolerances of gasket groove and allowance for radial expansion.
• 无摇臂钻床加工痕迹。
  No radial machine marks.
• 最少三层内部包裹，有利于防止挠曲。
  Minimum of three inner wraps to prevent buckling.
• 至少三处定位焊。
  Minimum of three tack welds.
• 至少三层填料包裹。
  Minimum of three filler wraps.
• 密封垫厚度的紧公差为± 0.18 mm。
  Close tolerance ±0.005” (0.18 mm) for gasket thickness.
• 最小宽度达127 mm内径7.62 mm。
  Minimum width up to 5” (127 mm) ID of 0.30” (7.62 mm).
• 由于质量的波动的影响，所接收的密封垫弹性需要进行定期地测试和检查。
  Gasket resiliency tested regularly and inspected at receiving due to sensitivity to variations of quality.

连接紧固性
JOINT TIGHTENING

• 所有小型锻钢阀门连接都采用多个多转螺母进行紧固，以提供均匀压力和超级零ppm密封性。
  All small forged steel valve joints are tightened with multiple nut runners providing uniform loading and superior zero ppm tightness.
  Warning: Gasket is not reusable.

填料腔和阀杆参数
PACKING CHAMBER AND
STEM PARAMETERS

• 阀杆经过硬化和研磨抛光，光洁度达16 RMS。
  Stem hardened and ground to 16 RMS finish.
• 平直度每25.4mm为0.03mm。
  0.001” per inch straightness
  (0.03 mm per 25.4 mm straightness).
• 圆柱度为0.08mm。
  0.003” (0.08 mm) cylindricity.
• 填料腔表面光洁度最大为63 RMS。
  63 RMS maximum surface finish of packing chamber.
• 直径间隙：
  阀杆-密封压盖，阀杆-后座：0.76 - 1.02 mm。
  填料腔-密封压盖：0.38 - 0.51 mm。
  Diametrical clearances:
  stem-gland, stem-backseat: 0.030–0.040” (0.76–1.02 mm).
  packing chamber-gland: 0.015–0.020” (0.38–0.51 mm).
• 最多为6个密封环。
  Maximum of six packing rings.
• 逐个压缩：对于石墨环，压力为3500-4000 psi.
  Individual compression: 3500– 4000 psi for graphite rings.