(1) 阀盖连接 - ANSI压力等级不同，连接结构也有所不同。
(1) Bonnet Joint – joint design varies with ANSI class rating.

(2) 铰链销 - 精密机加工实心销钉，强度最高，使用寿命最长。
(2) Hinge Pin – precision machined solid pin for maximum strength and service life.

(3) 铰链 - 能够承受迅速关闭而产生的冲击负载，确保使用寿命更长和连续关闭。
(3) Hinge– designed to withstand the shock load of quick closing to insure longer life and continued shut-off.

(4) 阀座环 - 坚固耐用，全流道(全端口)密封焊接装配在阀体内。
(4) Seat Ring – heavy duty, full ported seal welded into body.

(5) 连接端口 - 根据连接管道的情况，可选择法兰或对焊连接端口。
(5) End Connections – choice of flanged or butt weld ends for piping flexibility.

(6) 阀瓣挡块 - 在开启位置提供积极的止回功能；位置阀瓣在水平或垂直(流向朝上)管道的功能明显。
(6) Disc Stop – provides positive stop in open position; positions disc to effectively function in either horizontal or vertical (flow-up) pipe runs.

(7) 反旋转凸缘 - 凸缘允许阀瓣到阀座运动自如，同时防止阀瓣旋转和磨损。
(7) Anti-Rotation Lugs – lugs allow disc to seat freely and prevent disc spinning and wear.

(8) 阀瓣 - 坚固耐用的阀瓣通过螺栓和销钉固定在铰链上；接地阀座表面配置成对的阀座环，有利于有效的关闭。
(8) Disc – rugged disc is bolted and pinned to hinge; ground seating surface is mated to seat ring for positive shutoff.

(9) 阀体 - 全流道(全端口)，坚固耐用阀体，API 600标准壁厚，最大限度延长使用寿命。配置轮毂用于备选排泄阀。
(9) Body – full ported, heavy duty body with API 600 wall thickness for maximum service life. Provided with bosses for optional drains.

材料范围
Range of Materials

　　标准阀体/阀盖材料包括9个等级的碳钢，低合金钢和不锈钢。对于特殊应用，可以提供其它等级的合金钢和不锈钢。可提供完整系列的阀内件材料以满足各种应用环境。可提供标准或备选填料和垫圈材料，以满足各种应用环境。
　　Standard body/bonnet materials include nine grades of carbon, low alloy and stainless steels. For special applications, they can be supplied in other grades of alloy and stainless steel. There’s a full range of trim materials to match any service. Standard and optional gaskets are available for a wide variety of service conditions.

可靠的运行
Reliable Operation

　　这种阀门适用于水平或垂直(流向朝上)的管道，关闭迅速有效。阀体阀座环安装成3^o角度。这使得我们的旋启式止回阀无论安装在水平管道还是垂直(流向朝上)管道上，都能够实现完全的关闭。
　　Valves are designed to close quickly with positive shutoff in either horizontal or vertical (flow up) pipe runs. The body seat ring is installed on a 3^o angle. This allows our swing check valve to close completely even when installed in a horizontal pipe run with no flow.

易于维护
Easy Maintenance

　　我们的螺栓阀盖结构使得拆卸简单化，维护容易。例如，我们独特的螺纹阀座环易于接近进行维修或更换。
　　Our bolted bonnet design is simple to disassemble, easy to maintain. For example, our unique threaded seat rings are easily accessible for repair or replacement.

更长的使用寿命
Longer Life

　　我们坚固的铰链销/铰链和阀瓣结构适用于承受迅速关闭所产生的冲击，延长了使用寿命。阀瓣上的反旋转凸缘在可能产生旋转和磨损的湍流、高速流应用中更加稳定可靠。
　　Our rugged hinge pin/hinge and disc construction is designed to withstand the shock of quick closing and provides years of service. Anti-rotation lugs on discs extend service life in turbulent, high velocity services which can otherwise cause spinning and wear.

选择旋启式止回阀的通径
Sizing Swing Check Valves

　　在选择旋启式止回阀的通径时应该考虑到三个因素；通过阀门的压降，流体通过阀门的流速，与阀门其它管道部件的相对位置。
　　Three factors should be considered when sizing swing check valves; the pressure drop across the valve, the flow velocity of the fluid through the valve, and the location of the valve in relation to other piping components.
　　为了获得最好的性能，旋启式止回阀应该运行在流量速度足够将阀瓣稳定支撑在离开阀座的位置，或让阀瓣停止在全开的位置。应该避免应用在可能出现空穴现象的流速异常高速的场合。此外，此外，存在着接近阀瓣停止位置而可能使阀瓣变得不稳定的中等流速范围。应该避免落在这种流速范围内，以使阀门发挥出最好的性能，延长阀门的使用寿命。
　　For best performance swing check valves should operate with fluid velocity sufficient to hold the disc in a stable position off the seat or fully open against the disc stop. Extremely high velocities should be avoided due to possible cavitation. In addition, there is a mid-range of velocity where the disc may become unstable as it approaches the disc stop. Operation in these velocity ranges should be avoided to achieve best performance and valve life.

计算压降
Calculating Pressure Drop

　　请参考《技术资料》章节中有关旋启式止回阀流量系数和公式的“流量计算”内容，计算通过阀门的压降。
　　Please refer to “Flow Calculations” in the Technical Data section for swing check valve flow coefficient (Cv) and equations to calculate pressure drop through the valve.

计算流速
Calculating Velocity

　　《技术资料》内包括流速公式。在选择旋启式止回阀的通径时，阀座端口的流速应该控制在下列指定的一般范围内。
　　Velocity equations are included in the Technical Data Section. When sizing swing check valves, the seat port velocity should be controlled within the general ranges specified below.

　　0 – 55 – 避免这个范围。
　　0 – 55 – Avoid this range.
　　55 – 240 – 一般优化的运行流速范围(参阅注释)。
　　55 – 240 – Generally optimum operating velocity range (See note).
　　超过240 – 避免这个范围。
　　Over 240 – Avoid this range.
　　在此： v = 流体流动英尺³/磅的特定流量。
　　Where: v = The specific volume in ft³/lb of the fluid flowing.
　　注释：存在着一种中间运行流速，在这个范围内阀瓣变得不稳定。这种非优化的运行流速范围通常位于115 至135之间，但是，如果上游管道部件太靠近阀门，就有可能扩大这个范围。
　　Note: There is an intermediate operating velocity within this range at which the disc may become unstable. This non-optimum operating velocity range is generally from 115 to 135, however, upstream piping components placed in close proximity to the valve will tend to increase this range.

阀门位置的影响
Influence of Valve Position

　　如果过于靠近其它管道部件，如泵，控制阀，仪表，收缩管，三通，弯管，等等，旋启式止回阀可能会被湍流反作用。通常，旋启式止回阀与上游部件的距离至少要有管道直径的10倍，这样才能够将反作用降到最小程度。
　　Swing check valves can be adversely affected by turbulence if placed too closely to other piping components such as pumps, control valves, meters, reducers, tees, elbows, etc. In general a minimum of 10 pipe diameters of straight pipe should be provided upstream of a swing check valve to minimize adverse conditions.