常开常闭

请明确区分常开常闭阀。

Please differentiate clearly valve which is normally open and close .

本实用新型具有能耗低、无温升、使用方便、寿命长、常开常闭兼容一体的特点。

The utility model has the characteristics of low energy consumption , no temperature rising , convenient operation , long service life and compatibility of constant opening and constant closing .

高层建筑设置常开和常闭风口比较

Comparison of the Permanent Open and Close Vents Installed in the High rise Building

在临界转速附近，转子运行过程中裂纹处于常开或常闭状态。

The crack keeps open or close when the rotor runs near the critical speed .

带有信号输出端口：由电子控制主板里的常开、常闭、公共三个端口引线可外接电磁阀或增压泵。

S with signal output port : by electronic control in the mainboard to often open and closed , public three port fuses can external electromagnetic valve or booster pump .

控制方式：常开□、常闭□、自保式□。

Control mode : Normally open □, NC □, self-protection type □ .