安装建议和要求
INSTALLATION RECOMMENDATIONS AND REQUIREMENTS

垂直安装
VERTICAL INSTALLATIONS

　　通径DN150及以上的阀门避免安装在垂直排放位置（阀杆水平或阀盖指向侧面）。如果用户需要安装在这种位置，请咨询工厂，或者在订购时指明。
　　Avoid mounting valves 6" and larger in a vertical discharge position (valve stem horizontal or cover pointed sideways). If your installation requires this mounting position consult the factory or specify at time of order.

隔离关闭阀
ISOLATION SHUT-OFF VALVES

　　在自动控制阀的上游和下游应该安装蝶阀或类似的阀门，以便于进行维护维修。安装隔离阀使得用户不需要进行系统排放或使维修人员承受管线压力的威胁就能够进行维护维修。
　　Butterfly or similar type valves should be installed in the line upstream and downstream of the automatic control valve to allow for maintenance service. Installing isolation valves will allow you to perform maintenance service without draining the system or exposing service personnel to line pressures.

特别考虑因素
SPECIAL CONSIDERATIONS

浮球阀
FLOAT VALVES

• 由于可能出现的应用故障，因此应该避免在敞开式容器上安装阀门
  Installing valves over open tanks should be avoided due to possible servicing problems.
• 在浮球阀周围安装静水井，防止它们受到扰动的影响
  Install stilling wells around floats to protect them from turbulence.
• 远程安装的浮球控制阀应该用DN10口径的管道连接到主阀上
  Remote mounted float controls should be connected to the main valve with ³/₈" size tubing.

电磁阀
SOLENOID VALVES

• 电源线应该符合美国电气制造者协会NEMA规程，以确保正常的阀门工作状态和使用寿命。
  Electrical wiring should conform to NEMA codes to assure proper valve operation and longevity.

流量阀流速
RATE OF FLOW VALVES

• 蝶阀隔离阀不能够直接安装在阀门进口法兰上，因为其阀瓣将会接触到节流板。可以采用闸阀或球阀，或者可以将隔离阀安装在更上游的地方。
  A butterfly isolation valve cannot be installed directly to the valve inlet flange, as the disc will contact the orifice plate. A gate or ball type valve can be used or the isolation valve can be installed further upstream.

水位控制阀
ALTITUDE VALVES

• 在尽量靠近容器的地方安装阀门，最远不要超过管道口径的40倍，这样才能够确保精确控制。
  Install the valve as close to the tank as possible, a maximum of 40 pipe diameters to assure accurate control.
• 需要将一条液压控制管路将水位控制阀连接到容器上。为了提供精确的水头压力参数，管线应该连接到水柱的底部。液压控制管路的最小口径是DN15。在管线上应该安装一个关闭阀，以便于维修和启动。
  A sense line is required to connect the altitude control to the tank. To provide accurate reading of head pressure, the line should connect at the base of the water column. Minimum sense line size is ¹/₂". A shut-off valve should be installed in this line for service and start-up.

阀门通径 - 减压
VALVE SIZING — PRESSURE REDUCING

　　正确选择减压阀的通径相对来说比较简单。选型标准是最小流量，正常流量，最大流量和通过阀门的压降。下面是减压阀三种安装方式的说明。这些方式也可以应用在与减压功能结合在一起的其他任何功能上，如减压/止回阀和减压/电磁阀。
　　Selection of the correct size pressure reducing valve is a relatively simple process. Criteria for selection is minimum flow, normal flow, maximum flow and pressure drop across the valve. Following are explanations of the three types of PRV installations. These also apply to any functions combined with the reducing function, such as reducing/check and reducing/solenoid valves.

单个阀门安装
SINGLE VALVE INSTALLATION

　　如果一个阀门通径可以满足工作流量和要求，并且压降处于空穴区外，则可以安装单个减压阀。
　　A single reducing valve can be applied if operating flow, requirements are within the capacity of one size valve, and pressure drop is outside the Cavitation Zone.

1. 在最低到最高流量范围内，从通径图表中选择阀门通径。（考虑最低需要设备的要求。）
   Select the valve size from SIZING CHART that is within the range of low to high flow. (Consider requirements of lowest demand equipment.)
2. 止回压降（进口 - 出口）确保所需的出口压力处于推荐的最低出口设置点上，以避免空穴现象发生。（止回阀空穴图表，第32页）
   Check Pressure Drop (inlet-outlet) to insure that desired outlet pressure is above the recommended lowest outlet setting to avoid cavitation conditions. (Check Cavitation Chart page 32.)

并联安装
PARALLEL INSTALLATION

　　如果流量要求超出单个阀门的空穴区外，则可能需要并联安装一个较小的附属阀门。这种并联安装方式中，大阀门处理降到低流量空穴下的最大流量需求。小阀门扩大了两个阀门的最大流量。
　　If flow requirements fall outside the capacity of a single valve, an additional smaller valve installed in parallel may be required. In parallel installations, the larger valve handles the requirements for maximum flow down to its low flow capacity. The small valve extends to the sum of the maximum flow of both valves.

1. 在最低到最高流量范围内，从通径图表中选择阀门通径。
   Select the valve size combinations from SIZING CHART that is within low to high flow system range.
2. 止回压降（进口 - 出口）确保所需的出口压力处于指标性psig或止回空穴图表上，以避免空穴现象发生。
   Check Pressure Drop (inlet-outlet) to confirm desired outlet pressure is above index psig., or check Cavitation Chart.

串联安装
SERIES INSTALLATION

　　如果压降要求导致出口压力位于指标性psig以下，或者落在空穴区内，则可能需要串联安装两个阀门。每个阀门将起着避免落在空穴区内的作用，通过两个步骤，将高进口压力安全降到所需的出口压力。阀门通径以前面所述的最小-最大流量范围确定。
　　If pressure drop requirements cause the outlet pressure to be below the index psig., or fall in the Cavitation Zone, then two valves in series may be required. Each valve will function outside the cavitation zone to safely drop the high inlet pressure, in two steps, to the desired outlet pressure. Valve size is based upon the Minimum - Maximum flow ranges previously explained.