泵自动再循环阀，最小流量阀，也称自动再循环阀、三通回流阀、泵保护阀或空排止回阀

RETZ工业/美国瑞茨，我们一直致力于流体控制领域的持续创新，始于2005……自动再循环阀是一种泵保护装置.它自动对离心泵（尤其输送热水介质）在低负荷运行时泵体内可能出现的部分气蚀损害和不稳定进行保护.一旦泵流量低于预设流量,旁路完全打开以确保泵所需最小流量.即使主路全关闭,主路流量为零,最小流量也可以通过旁路进行自动循环.压力通过旁路中的集成多级节流减压阀降压。The automatic recirculation valve is a pump protection device that automatically protects the centrifugal pump (especially when conveying hot water medium) from possible cavitation damage and instability in the pump body during low load operation. Once the pump flow rate is lower than the preset flow rate, the bypass is fully opened to ensure the minimum required flow rate of the pump. Even if the main circuit is fully closed, the main circuit flow rate is zero, The minimum flow rate can also be automatically circulated through the bypass. The pressure is reduced by the integrated multi-stage throttle and pressure reducing valve in the bypass.

进口泵自动再循环阀 最小流量阀 自控回流阀慨述 Principle description

自动再循环阀（自控回流阀）是一个独立的系统，能够动态的感知主路流量的变化，随主路流量调整旁通流量。它集止回、流量感知、旁通流量控制、多级减压功能于一身 RETZ The automatic recirculation valve (automatic return valve) is an independent system, which can dynamically sense the change of the main flow and adjust the bypass flow with the main flow. It integrates check, flow sensing, bypass flow control and multi-level pressure reduction functions

当主阀处于全开位置时（图3a），旁通阀关闭。阀瓣带动操纵杆上升，由杠杆原理，操纵杆使副阀朝关闭方向移动直至完全关闭。其流场分布见图4 When the main valve is in the fully open position (Fig. 3a), the bypass valve is closed. The valve flap drives the operating lever to rise. Based on the lever principle, the operating lever moves the auxiliary valve in the closing direction until it is completely closed. The flow field distribution is shown in Figure 4

当主阀逐渐关闭时（图3b），阀瓣下降，操纵杆和副阀脱离，在压差的作用下，副阀逐渐开启 When the main valve is gradually closed (Fig. 3b), the valve clack drops, the control lever and the auxiliary valve are separated, and the auxiliary valve is gradually opened under the action of differential pressure

当主阀关闭时（图3c），旁通开度，满足泵的最小流量。旁通阀具有多级减压功能，其流场分布见图5 When the main valve is closed (Fig. 3c), the bypass opening is the largest to meet the minimum flow of the pump. The bypass valve has the function of multistage pressure reduction, and its flow field distribution is shown in Figure 5

进口泵自动再循环阀 最小流量阀 自控回流阀主要特点DESIGN FEATURES

离心泵用于锅炉水、冷凝液或其他液体供给时，在泵启动和小工艺流量时需要进行最小流量保护  When the centrifugal pump is used to supply boiler water, condensate or other liquids, the minimum flow protection is required when the pump is started and the process flow is small

由于液体摩擦和压力损失，液体的温度会升高。图1a为典型的温度、压头和流量关系曲线。额定流量点，温度正常，对泵的操作无影响，因为泵内产生的热量随流出泵的液体散发。当工艺流量减少，散热降低，液体温度升高并汽化，过热和蒸汽压会破坏泵的密封、轴承和其他旋转零件 The temperature of the liquid will rise due to liquid friction and pressure loss. Figure 1a shows a typical temperature, head and flow relationship curve. The normal temperature at the rated flow point has no impact on the operation of the pump, because the heat generated in the pump is emitted with the liquid flowing out of the pump. When the process flow decreases, heat dissipation decreases, liquid temperature rises and vaporizes, overheating and steam pressure will damage the seals, bearings and other rotating parts of the pump

图1b与1c为泵产生内部循环流动，发生气穴，破坏叶轮 Figures 1b and 1c show that the pump generates internal circulation flow, which causes cavitation and damages the impeller

技术规范 Technical specifications 

通径:1-1/2”~12”

压力等级：ANSI/ASME 150Lb~900Lb(PN1.6~16Mpa)

适用温度：-20~150℃

连接方式：法兰

材质:WCB/304不锈钢