远程执行机构
Remote Actuators

　　在许多应用场合，操作阀门可能要求采用电动、气动或液动执行机构。这种装置主要应用在下列阀门上：(1) 太大或具有很高的关闭压差，以至于人工无法关闭；(2) 操作人员无法接近操作；(3) 作为系统的一部分，要求许多阀门同步操作；(4) 必须进行远程控制，对于危险区域的紧急关闭常常是不可缺少的。
　　In many applications, operation of valves may require the use of electric, pneumatic or hydraulic actuators. Such applications include those where the valve (1) is too large or has too high a differential shut-off pressure for manual operation; (2) is not accessible for manual operation; (3) is part of a system requiring simultaneous operation of many valves; (4) must be triggered from a remote location, as is often essential for emergency shut-off in hazardous areas.
　　我们很愿意配置任何类型或根据用户的规定制造执行机构，或者对于用户特殊的应用条件提供我们的建议。所有美国太平洋闸阀、截止阀和止逆阀(单向阀)都可以配置电动、气动或液动马达执行机构或缸体执行机构。
　　We will gladly furnish any type or make of actuator you specify, or make recommendations for your particular service conditions. All Pacific gate, globe and non-return valves can be supplied with electric, air, gas or hydraulic driven motor actuators or cylinder actuators.

马达执行机构
Motor Actuators

　　用于升降阀杆(明杆)阀门的马达执行机构可以采用空气、燃气、液体或电力作为动力。最常见的方法是电动马达执行机构，因为一般情况下，这是一种性价比最高的方法。
　　Motor actuators for rising stem valves can be powered by air, gas, hydraulic or electric power. The most common method of actuation is the electric motor actuator, as it is generally the most cost effective.
　　电动马达执行机构操作的阀门能够满足广泛的需求，包括操作循环时间，整体或远程控制，启动器和指示器，以及容易得到的电源。这种执行机构与缸体执行机构相比，比较不适用于故障安全操作，因为电动马达执行机构通常需要更多的储备能源。
　　Electric motor actuated valves can be provided to meet the broadest range of requirements including operating cycle time, use of integral or remote controls, starters and indicators, and a wide range of power sources. They are less readily adaptable to fail-safe operation than cylinder actuators because they generally require more stored energy.
　　气动马达执行机构通常用于很危险的区域，在那种地方没有电源或者不允许电源存在。这种类型执行机构的主要优点是气源消耗，特别是适用于大通径阀门。除非气源供应系统是经过特殊配置，以满足这种类型执行机构的要求，或者高齿轮传速比和长冲程的组合可能会耗尽整个气源系统。和电动马达执行机构相同，这种执行机构也不适用于故障安全模式。
　　Air motor actuators are often specified in very hazardous locations where electric power is not available or permitted. The major disadvantage of this type of actuator is air consumption, particularly when applied to large valves. The combination of high gear ratio and long stroke can drain an entire air system unless the air supply system is specially designed to accommodate this type of actuator. Like electric motor actuators, these are not readily adaptable for a fail-safe mode.

1. 阀门通径，型号或规格说明。
   Valve size, figure number or description.
2. 阀门操作条件(压力，温度，流量和流体介质)。
   Valve operating conditions (pressure, temperature, flow rate and fluid).
3. 最大(关闭)压差。
   Maximum differential (shut-off) pressure.
4. 主要能源供应：
   Primary power supply:
   1. 电压，相数，频率，
      electric-voltage, phase cycles,
   2. 气体或液体，可供的流量，最大和最小压力。
      gas or hydraulic-fluid, available flow rate, maximum and minimum pressure.
5. 控制电压。
   Control voltage.
6. 阀杆位置。
   Valve stem position.
7. 关闭时间和频率。
   Closing time and frequency.
8. 所要求的结构(NEMA，等等)，或者当地环境。
   Required construction (NEMA, etc.) or local environment.
9. 辅助设备：
   Auxiliary equipment:
   1. 按钮板，
      push-button stations,
   2. 可逆控制器，
      reversing controllers,
   3. 位置指示器，
      position indicators,
   4. 其它(例如，阀杆盖，等等)
      other (i.e., stem covers, etc.)
10. 特殊要求(例如，辐射，地震，等等)
    Special requirements (i.e., radiation, seismic, etc.)
11. 如果有的话，特别指定的制造商或品牌。
    Preference for specific manufacturer, if any.