Service Recommendations for Valves
闸阀应用建议
Service Recommendations for Gate Valves
1. 闸阀通常应用于开启-关闭场合，不推荐用于节流应用。
Gate valves are normally used for on-off service and are not recommended for throttling service.
2. 闸阀通常安装在水平管道上，阀杆垂直向上。也可以安装在垂直管道或者阀杆不是垂直向上的水平管道上，但是根据阀门的通径大小、应用环境和材料的具体情况，可能要求特殊的结构。如果购买的阀门准备采用特殊的安装方式，则在订购时，应该说明阀门的朝向。
Gate valves are normally installed in horizontal pipe runs with the stem vertical. They can also be installed in vertical or horizontal pipe runs with the stem other than vertical, but may require special construction depending on valve size, service conditions and materials. WHEN PURCHASING VALVES FOR OTHER THAN NORMAL INSTALLATION, THE VALVE ORIENTATION SHOULD BE SPECIFIED.
3. 对于温度超过260oC的应用环境，建议采用柔性或拼合式楔形闸板，避免楔形闸板由于热膨胀而被卡住。这种情况在阀门冷关闭而后热开启状态下可能发生。
Flexible or split wedges are recommended for service above 500oF to avoid wedge binding due to thermal expansion. This may occur if the valve is closed when cold, and then heated to operating temperature.
4. 当用于高速流体(湍流)或热循环应用时，为了避免松开，螺纹阀座环应该锁焊在阀体上。请在订购时加以指定说明。
Threaded seat rings should be lock welded to the body when used in high velocity (turbulent) or thermal cycling services to avoid loosening. Please specify.
5. 在以足够的力量关闭闸阀后，阀杆应该稍微回转(1/8至1/4圈)，以释放阀杆负载。这使得阀杆能够稍微膨胀，不会卡住或损坏阀门，也不会影响关闭效果。
After closing a gate valve with sufficient force to develop shutoff, the stem should be backed off slightly (1/8 to 1/4 turn) to relieve stem load. This will enable the stem to expand slightly without binding or damaging the valve and will not affect shutoff.
6. 如果拆卸掉阀座环安装耳柄，则高度整体性关闭闸阀可以用在热水出口或采用软铁的管道系统中。在订购时请加以指定说明。
High Integrity Shutoff gate valves can be used for hot tapping or in pipeline services where a soft pig is used if the seat ring installation lugs are removed. Please specify.
截止阀应用建议
Service Recommendations for Globe Valves
1. 通常在安装截止阀时，要让流体流进和压力位于阀瓣的下方。如果流体流进是在另一个方向，那么在安装之前，要与制造商进行确认。在某些特定的应用条件下，或者阀门配置缸体或电动马达执行机构，那么设计和安装阀门，让流体从阀瓣上方流进，就可能具有成本低的优点。如果执行机构是根据这些条件进行选型，则必须小心谨慎，确保阀门安装正确。
Globe valves are normally installed with flow and pressure under the disc. Always check with the manufacturer before installing valves with flow in the other direction.Under certain service conditions or when valves are equipped with cylinders or electric motor actuators, there may be a cost advantage in the designing and installing the valves with flow over the disc. If actuators are sized for these conditions, care must be taken to assure valves are installed correctly.
2. 当用于高速流体(湍流)或热循环应用时，为了避免松开，螺纹阀座环应该锁焊在阀体上。请在订购时加以指定说明。
Threaded seat rings in valves in services with high velocity (turbulent) flow or thermal cycling should be lock welded to the body to avoid loosening. Please specify.
3. 通常截止阀适用于大多数节流应用，并且当管线流速(英尺/秒)不超过240 (v是流体介质的特定流量英尺3/磅)时，使用寿命也是最长的。不建议截止阀长期在开启度小于10%状态下用于节流应用，因为可能产生剧烈的振动、噪音，并且损坏阀瓣和阀座。采用流量较小的更小通径的阀门或V型端口阀内件，可以增加阀门开启度，从而避免造成损坏。连续严酷的节流应用可能要求采用控制阀。
Conventional globe valves are suitable for most throttling applications and will provide the greatest service life where pipe line velocity in FT/SEC does not exceed 240 . (v is a specific volume of flowing medium, ft.3/lb.) Prolonged throttling at less than 10% open is not recommended due to the possibility of excessive vibration, noise and damage to disc and seats. Use of smaller valves or V-Port trim with lower flow capacity may permit the valve to be open at a greater percentage, thus avoiding damage. Continuous severe throttling applications may require a control valve.
