Check valve with counter weight/ Butterfly buffer check valve with heavy hammer
HH44X micro-resistance slow-closing check valve is used for water supply and drainage pipelines. It is installed at the outlet of the pump to prevent the backflow of the medium and eliminate the destructive water hammer, and can effectively reduce the pressure of the valve closing water hammer, which can ensure the safe operation of the pump. It has the characteristics of light valve disc, large opening, significant power saving effect, small fluid resistance, novel design of water hammer elimination mechanism, stable and reliable sealing performance, wear resistance, long service life, stable operation, no vibration, no noise, etc.
1. When the water medium flows backwards, the valve flap is closed quickly and then slowly closed, and the slow closing time can be adjusted arbitrarily within 0`60 seconds
2. When the medium in the pipeline flows backwards, it can be adjusted so that the peak water hammer generated is greater than 1.5 times the working pressure.
3. When the medium is flowing backwards, it can be adjusted so that the reverse speed of the water pump does not exceed 1.3 times the rated speed of the motor.
Check valve is mainly composed of valve body, butterfly plate, regulating valve, and buffer cylinder. Buffer cylinder is also composed of two oil chambers, connected internally by a one-way valve, and externally connected by a regulating valve. When the valve is opened, the medium water pushes the butterfly plate.
At this time, the hydraulic oil in the buffer cylinder quickly flows from cavity 1 to cavity 2 through the check valve inside. When the valve is closed, the medium returns to the first cavity.
The high pressure oil compressed in the 2 cavity can only flow slowly into the 1 cavity through this 1/3 area, so that the valve flap is slowly closed and the pressure of the water hammer peak is weakened. Limits the generation of destructive water hammer.
Due to the function of the above-mentioned regulating valve, the time for the hydraulic oil to flow from cavity 2 back to cavity 1 can be adjusted by adjusting its opening. That is to adjust the closing speed of the valve. Therefore, when the opening degree of the regulating valve is smaller, closing speed of the corresponding valve is slower. Then longer the water discharge, the smaller the water hammer, and vice versa. Users can adjust appropriately according to the needs of the scene.
The valve is opened by the flow of the medium when the pump or fan starts while lifting the hammer. The stem moves the external cushion piston inward and outward as the disc unwinds. The oil from the top of the piston passes through an internal check valve into the lower part of the piston to prepare the disc for closing. When the pump or fan stops working, because of the pressure medium backflow and heavy hammer down to make the disc quickly shut down, but because of the lower part of the piston in cylinder oil buffers is compressed, prevent disc closing fast, the compressed oil only through trace regulator slowly into the piston top space, thereby control the disc when the last is about 30 ° from sealing ring slowly-closing.
However, to ensure that the valve has good sealing performance in the case of low backflow medium pressure when the disc is at free closing to about 30° from the sealing ring surface, the travel switch located outside the valve body is heavy. At this time, the electromagnetic directional valve is a power failure, because the electromagnetic directional valve is normally open, so at this time to help close the medium through the electromagnetic directional valve into the device to help close, the forced valve disc closed. The solenoid directional valve is synchronized with the motor when it is opened. The motor is energized at the same time, the electromagnetic valve to help close the off medium cut off, at the same time to help close the outlet of the device, will help close the device in the medium back to the original place, so that there is resistance to open the valve.