即使在理想的实验室测试环境下，不考虑法兰光洁度和密封垫负载，API 600所规定的没有石墨的标准波纹钢板密封垫也被认为不适用于低排放场合。在测试了几种替代密封垫后，我们选择了在我们的测试中表现性能最好的密封垫 - 带石墨填料通路的波纹钢板密封垫。
　　Standard corrugated steel gaskets without graphite as specified in API 600 were found to be an unacceptable choice for low emission service, even under ideal laboratory test conditions, and regardless of flange finish and gasket load. After testing several alternative gaskets, we selected the best performing gasket in our tests - a corrugated steel gasket with graphite filled channels.

典型测试结果
TYPICAL TEST RESULT:

　　DN150，150磅级阀门，经过3700次循环开关测试后，泄露为零ppm。
　　3700 cycles with zero ppm for 6" Class 150.

结构特征：
DESIGN FEATURES:

• 通过广泛的实验室测试，保证泄漏不会超过20 ppm。
  Ensures leakage of no more than 20 ppm as demonstrated through extensive laboratory testing.
• 经过长期循环测试后，不需要回位扭矩。
  Requires no retorquing after long cycling.
• 在温度压力大幅波动状态下，保持高效性。
  Effective under wide fluctuations of temperature and pressure.
• 不受法兰表面光洁度的影响。
  Insensitive to flange finish.
• 石墨通道的钢壁防止氧化、腐蚀和爆裂的破坏。
  Steel walls of graphite channels provide additional protection from oxidation, corrosion and blow-out.
• 密封具有柔性石墨的优点（0-14pH，-200至1093^oC）。
  Seal offers the advantage of flexible graphite (0 –14pH, -328°F to +2000°F).
• 较小的螺栓扭矩。
  Lower bolt torques.
• 现代扭转方式。
  Modern torquing methods.