超压活门
一、名称
OVERPRESSURE VALVE
超压活门
二、件号
3290718-1(6743A010000)
三、章节号
36-12-69
四、适用机型
A330/A340
五、系统
36 PNEUMATIC
气源
六、安装位置
发动机吊架
七、部件原理
1. Overpressure Valve
(1) The pneumatic system overpressure valve is a pneumatically-operated, spring-loaded open, butterfly-type valve. It is used in the aircraft’s pneumatic system.
(2) The pneumatic system overpressure valve has:
– a visual position indicator
– a test port
– a valve body assembly
– a butterfly plate
– an actuator support assembly
– an actuator assembly.
(3) The actuator assembly has:
– a piston assembly
– Chamber A
– a vent
– Chamber B
– a connecting link
– a spring.
(4) The piston assembly has a static seal and a moveable seal.
(5) Refer to Figure 2.
1. 超压活门
(1) 气动系统超压活门是一个气动操作、弹簧开启的蝶形活门。它用于飞机的气动系统。
(2) 气动系统超压活门有：
– 一个可视位置指示器
– 一个测试口
– 一个活门壳体组件
– 一个蝶板（活门板）
– 一个作动器支撑组件
– 作动器组件。
(3) 作动器组件包括
– 活塞组件
– 腔室 A
– 排气孔
– B 室
– 一个连杆
– 一个弹簧。
(4) 活塞组件有一个静密封和一个动密封。
(5) 参见图 2。
2. Operation
A. Pneumatic System Overpressure Valve
(1) Upstream air pressure enters a tube and flows into Chamber A, where it pushes against the force of the spring in Chamber B. During periods of operation, when upstream air pressure is less than a specified value, the force of the spring holds the butterfly plate in the open position. When the upstream air pressure becomes more than the specified value, it causes the piston assembly to compress the spring. This causes the butterfly plate to start to close. As the upstream air pressure becomes higher, the butterfly plate moves to the fully closed position.
(2) The static seal prevents leaks around the piston assembly and decreases the amount of contamination that enters the pneumatic system overpressure valve. When the static seal moves away from the wall of the actuator assembly, the area of the piston face increases. This starts the butterfly plate to close with a quick movement.
(3) The vent prevents unwanted pressure on the piston face between the static seal and the moveable seal. This unwanted pressure (if not released through the vent) can cause the piston assembly to move before the upstream pressure increases to the specified value.
2. 操作
A. 气动系统超压活门
(1) 上游气压进入管道并流入腔室 A，在腔室 B 中受到弹簧力的推动。在运行期间，当上游气压小于规定值时，弹簧力将蝶板保持在打开位置。当上游气压超过规定值时，会导致活塞组件压缩弹簧。这将导致蝶板开始关闭。当上游气压变更高时，蝶板会移动到完全关闭的位置。
(2) 静态密封可防止活塞组件周围泄漏，减少进入气动系统超压活门的污染量。当静态密封远离执行器组件的壁时，活塞面的面积就会增大。从而启动蝶板快速运动关闭。
(3) 排气孔可防止在静密封和动密封之间的活塞面上产生不必要的压力。这种不需要的压力（如果不通过排气孔释放）会导致活塞组件在上游压力增加到规定值之前移动。
八、工作参数
九、在飞机系统中的工作原理及互联
An Overpressure Valve (OPV) gives protection to the downstream pneumatic system if the PRV does not operate correctly.
The OPV is a pneumatically actuated valve and is normally open.Muscle pressure for valve actuation is tapped from an integral pressure port located upstream of the valve.
In case of overpressure caused by the bleed valve failure, the overpressure valve closes.
A fully pneumatic Overpressure Valve (OPV) protects the system against overpressure.
如果 PRV 无法正常工作，超压活门 (OPV) 可为下游气动系统提供保护。
OPV 是一个气动作动的常开活门。用于驱动活门的气压从位于活门上游的一个整体压力口获得。
在引气活门失效导致超压的情况下，超压活门会关闭。
全气动超压活门 (OPV) 可防止系统超压。
OVERPRESSURE PROTECTION
If the bleed regulated pressure rises above 60 psi, the BMC detects an overpressure condition and closes the PRV. A warning message is displayed on the EWD and the BLEED page comes up automatically on the SD showing the HPV and the PRV closed in amber.
In addition to the overpressure electrical monitoring done by the BMC,the OPV gives a fully pneumatic back up protection in case of failure.The OPV is designed to start to close automatically when the upstream pressure increases above 75 psi and is fully closed at 85 psi. The valve remains closed as long as the upstream pressure is higher than 52 psi (±3 psi).
超压保护
如果引气调节压力升至 60 psi 以上，BMC 会检测到超压情况并关闭 PRV。EWD 上会显示警告信息，SD 上会自动出现引气页面，显示 HPV 和 PRV 已关闭的琥珀色信息。
除了 BMC 进行的超压电气监控外，OPV 还可在发生故障时提供完全气动的后备保护。OPV 的设计是在上游压力超过 75 psi 时开始自动关闭，并在 85 psi 时完全关闭。只要上游压力高于 52 psi (±3 psi)，活门就会保持关闭。
Overpressure valve
(a) Operation
The overpressure valve (6 in. dia) protects the downstream pneumatic system if the bleed valve does not operate correctly (overpressure).The overpressure valve is entirely pneumatic and normally open.The valve closes depending on the upstream pressure:
– the valve is normally fully open when the upstream pressure is lower than 75 psig
– the valve is controlled to the closed position when the upstream pressure is higher than 85 psig plus 0, minus 10 psig.
After closure due to overpressure, the valve opens again as soon as the upstream pressure is 52 psig plus or minus 3 psig.
超压活门
(a) 操作
超压活门（直径 6 英寸）在引气活门无法正常工作（超压）时保护下游气动系统：
– 当上游压力低于 75 psig 时，活门通常全开。
– 当上游压力高于 85 psig 正 0 负 10 psig 时，活门被控制在关闭位置。
因超压而关闭后，只要上游压力为 52 psig 正负 3 psig，活门就会再次打开。
