Actuated on-off valves shall be specific valves as exactly defined in piping specifications unless special requirements such as actuator style, stroking speeds or tight shutoff dictate otherwise.

• 受驱动的开关阀应是如配管规范中定义的特定阀门，除非另有例如执行机构的类型，开关速度或不泄漏关闭的规定。