Flue check valve introduction

First, the introduction of multi-function Pump Control Valve

　　The multi-function water pump control valve is a new type of HYDRAULIC CONTROL VALVE. One valve can replace the electric butterfly (gate) valve, check valve and water hammer eliminator. It can automatically realize the slow opening when the pump is turned on, the quick closing and the slow closing when the pump is stopped, without any electrical control and other power and manpower, and no hydraulic device.

The main advantages of the multi-function water pump control valve are:　　
(1) No operational control is required. The water pressure difference between the front and the rear of the valve is used as the control power when the pump is started and stopped, and has the function of automatically opening and closing with the opening and closing of the water pump.　　
(2) The valve opening and closing action can effectively prevent accidents caused by the water hammer pressure wave rising. According to the field use survey and actual measurement, the peak value of the pump water hammer pressure is within 1.3 times of the working pressure.　
(3) No on-site debugging is required, and the applicable working conditions are wide.　　
(4) Basically no maintenance required. Since one valve replaces the three VALVES, maintenance and repair work is greatly reduced.　　
(5) The resistance loss is small. With streamlined and wide valve body design, the resistance loss is reduced by more than 50% compared with similar foreign products. For example, when the DN200 product is in the economical flow rate of v=2m/s, the loss of the multi-function pump control valve is 0.7m, while the foreign similar products are 1.5m.　　
Second, the structure and working principle of the multi-function water pump control valve　
1 structure　　
The structure of the multi-function water pump control valve is shown in Figure 1. It consists of a main valve and an external accessory. The main valve includes a valve body, a main valve plate, a slow-closing valve plate, a valve stem, a valve seat, and a diaphragm controller (including a valve cover, a diaphragm seat, a diaphragm, and a diaphragm pressure plate): the external accessory has a control valve and a filter. , emptying valve, micro check valve. The micro check valve is a special fitting with a restriction hole in its non-return direction. See Figure 2 for the installation form.　　
2 Working principle　　
Before the pump starts, the pressure at the outlet end of the valve acts on the main valve plate, the valve is in the closed position, and the upper chamber of the diaphragm controller is connected to the pressure water, and the lower chamber is connected to the low pressure at the inlet end of the valve.　　
After the pump is started, the inlet pressure of the valve gradually increases, and the pressure water slowly enters the lower chamber of the diaphragm controller through the connecting pipe at the inlet end of the valve, so that the main valve plate is slowly opened, and the opening speed can be adjusted through the control valve.
When the pump is stopped, the pressure at the inlet of the valve is reduced. When approaching zero flow, the main valve plate closes rapidly under the action of its own gravity. As the pressure at the inlet end of the valve decreases, the pressure water at the outlet end of the valve enters the upper chamber of the diaphragm controller through the connecting pipe, and the lower chamber water is pressed back to the inlet end of the valve through the connecting pipe at the inlet end of the valve, and the slow closing valve plate is slowly closed, and the slow closing time can be Adjusted by a control valve. The quick closing of the main valve plate and the slow closing of the slow closing valve plate comply with the two-stage closing law, which can effectively eliminate the water hammer.