Similarly, high-level events can be decomposed into one or more low-level events or actions; for example, changing a pressurecontrolvalve, sounding an alarm, or signaling an alert.
Wherein the controlpressure is called pressurecontrolvalve to control the flow of known flow control valve to control flow through ﹑ called off and the direction control valve.
其中控制压力的称为压力控制阀，控制流量的称为流量控制球阀，控制通﹑断和流向的称为方向控制球阀。
3
The old special pressurecontrolvalve is substituted by the currency valve which is a mature product.