结构特点 Structural Characteristic

水力控制阀就是用水压控制的阀门，它由一个主阀(如图所示)及其附设的导管、导阀、针阀、球阀和压力表等组成。根据使用目的、功能及场所的不同可变成遥控浮球阀、减压阀、缓闭止回阀、流量控制阀、泄压阀、水力电动控制阀等。水力控制阀分隔膜型和活塞型两类，工作原理相同，都是以上下游压 P为动力，由导阀控制，使隔膜(活塞)液压式差动操作，完全由水力自调节，从而使主阀阀盘完全开启或完全关闭或处于调节状态。当进入隔膜(活塞控制室内的压力水被排到大气或下游低压区时，作用在阀盘底部和隔膜下方的压力值就大于上方的压力值，所以将主阀阀盘推倒到完全开启的位置;当进入隔膜(活塞)上方控制室内的压力水不能排到大气或下游低压区时，作用在隔膜(活塞)上方的压力值就大于上方的压力值，所以就会把主阀阀盘压到完全关闭的位置;当隔膜(活塞)上方控制室内的压力值处于入口压力与出口压力中间时，主阀阀盘就处于调节状态，其调节位置取决于导管系统中的针阀和可调导阀的联合控制作用。可调导阀可以通过下游的出口压力并随它的变化而开大或关小其自身的小阀口，从而改变隔膜(活塞)上方控制室的压力值，控制主阀阀盘的调节位置。

s a kind of valve controlld by hydraulic pressure. which consists of a main vaive (as shown in the igure) plus the aditional guide tube, pilot vave, needle valve, ball valve, pressure gauge, ete. According to diferences in application purpose, unction and places,its derivatives include remote control floating ball valve, pressure reducing valve, slow-shut check valve, flow control valve, relief valve, hydraulic electric control valve, etc. he hydraulic control valve is divided into two kinds: diaphragm and piston, Both follow the same working principle, which are powered by the difference between the upstream pressure and the downstream pressure aP and controlled by the pilot valve, making the hydraulic diferential operation of the diaphragm (piston) and the fully automaatic hydraulic regulation so that the main valve disc is fully open, fully closed or in a state of regulation. When the hydraulic water going into the contral cabinet over the diaphragm (piston) is discharged into the atmosphere of the lower pressure area downstream the value of pressure onthe die a water downside below the diaphragm wil be larger than that on the top so theat the main valve clsc is pushed to the pstina presste going into the control cabinet over the diaphragm (piston) is not discharged into the atmosphere or the lower pressure area downstream, the value of pressure on the below the diaphragm will be larger than that on the top so that the main valve disc is pushed to the position of ful closing; when the value of pressure in the control cabinet over the diaphragm (piston) is between and adjustable pilot valve in the conduit system. The adjustable pilot valve can adjust its valve let opening along the change of the downstream outlet pressure so as to change the value of pressure in the control cabinet over the diaphragm (piston) to contro the regulating position of the main valve disc.