Types and working principles of hydraulic control valves:
1. The concept of hydraulic control valve: The hydraulic control valve is a valve controlled by water pressure. It consists of a main valve and its attached conduit, pilot valve, needle valve, ball valve and pressure gauge.
2. Types of hydraulic control valve: according to the purpose, function and location, it can be evolved into remote control float valve, pressure reducing valve, slow closing check valve, flow control valve, pressure relief valve, hydraulic electric control valve, water pump control valve Wait. According to the structure, it can be divided into two types: diaphragm type and piston type.
3. The working principle of the diaphragm type and piston type valves of the hydraulic control valve is the same. Both the above downstream pressure difference △P is the power, which is controlled by the pilot valve, so that the diaphragm (piston) hydraulic differential operation is completely automatic. Adjust, so that the main valve disc is completely opened or completely closed or in an adjustment state. When the pressure water entering the control chamber above the diaphragm (piston) is discharged to the atmosphere or downstream low pressure area, the pressure value acting on the bottom of the valve disc and below the diaphragm is greater than the pressure value above, so push the main valve disc to fully open When the pressure water entering the control chamber above the diaphragm (piston) cannot be discharged to the atmosphere or downstream low pressure area, the pressure value acting on the diaphragm (piston) is greater than the pressure value below, so the main valve disc Press to the fully closed position; when the pressure in the control chamber above the diaphragm (piston) is between the inlet pressure and the outlet pressure, the main valve disc is in an adjustment state, and its adjustment position depends on the needle valve and adjustable in the catheter system The combined control function of the pilot valve. The adjustable pilot valve can open or close its own small valve port through the downstream outlet pressure and change with it, thereby changing the pressure value of the control chamber above the diaphragm (piston) and controlling the adjustment position of the square valve disc.
Selection of hydraulic control valve:
The hydraulic control valve is a valve controlled by water pressure. It consists of a main valve and its attached conduit, pilot valve, needle valve, ball valve and pressure gauge.
When using hydraulic control valves, first pay attention to the selection. Improper selection will cause water blocking and air leakage. When selecting a hydraulic control valve, you must multiply the equipment’s hourly steam consumption by 2-3 times the selection ratio as the maximum condensate volume to select the water discharge of the hydraulic control valve. In order to ensure that the hydraulic control valve can discharge the condensed water as soon as possible when driving, and quickly increase the temperature of the heating equipment. Insufficient discharge energy of the hydraulic control valve will cause the condensate to not be discharged in time and reduce the thermal efficiency of the heating equipment.
When selecting a hydraulic control valve, the nominal pressure cannot be used to select the hydraulic control valve, because the nominal pressure can only indicate the pressure level of the hydraulic control valve body shell, and the nominal pressure of the hydraulic control valve is very different from the working pressure. Therefore, the displacement of the hydraulic control valve should be selected according to the working pressure difference. The working pressure difference refers to the difference between the working pressure before the hydraulic control valve minus the back pressure at the outlet of the hydraulic control valve. The selection of hydraulic control valve requires accurate steam blocking and drainage, high sensitivity, improved steam utilization, no steam leakage, reliable working performance, high back pressure rate, long service life, and convenient maintenance.
Any hydraulic control valve actuator is a device that uses energy to drive the valve. This kind of hydraulic control valve device may be a manually operated gear set, a hydraulic control valve to switch the valve, or an intelligent electronic component with a complex control and measurement device, which can be used to achieve continuous valve adjustment. With the development of microelectronics technology, hydraulic control valve actuators have become more complex. Early actuators were nothing more than motor gear transmissions with position sensing switches. Today’s actuators have more advanced functions. The hydraulic control valve can not only open or close the valve, but also detect the working status of the valve and the actuator to provide various data for predictive maintenance.
The most extensive definition of a hydraulic control valve for an actuator is: a drive device that can provide linear or rotary motion, which uses a certain driving energy and works under a certain control signal.
The hydraulic control valve actuator uses liquid, gas, electricity or other energy sources and converts it into a driving function through a motor, a cylinder or other devices. The basic actuator is used to drive the hydraulic control valve to the fully open or fully closed position.
Hydraulic control valve installation:
The hydraulic control valve is a valve controlled by water pressure. The hydraulic control valve consists of a main valve and its attached conduit, pilot valve, needle valve, ball valve and pressure gauge. According to the purpose of use, function and location, it can be evolved into remote control float valve, pressure reducing valve, slow closing check valve, flow control valve, pressure relief valve, hydraulic electric control valve, water pump control valve, etc.
Fix the valve vertically on the water inlet pipe, and then connect the control pipe, stop valve and float valve to the valve. The valve inlet pipe and outlet pipe connecting flange H142X-4T-A is 0.6MPa standard flange; H142X-10-A is 1MPa standard flange. The diameter of the inlet pipe should be greater than or equal to the nominal diameter of the valve, and the outlet should be lower than the float valve. The float valve should be installed more than one meter away from the water pipe; drill a small hole in the water tank where the outlet pipe is higher than the water level to prevent the water from returning in the air. When in use, the shut-off valve should be fully open. If more than two valves are installed in the same pool, the same level should be maintained. Since the closing of the main valve lags behind the closing of the float valve for about 30-50 seconds, the water tank must have enough free volume to prevent overflow. In order to prevent impurities and sand particles from entering the valve and causing malfunction, a filter should be installed in front of the valve. If it is installed in an underground pool, an alarm device should be installed in the underground pump room.
A filter should be installed before the hydraulic control valve, and it should be easy to drain.
The hydraulic control valve is a self-lubricating valve body that uses water and does not require additional lubrication. If the parts in the main valve are damaged, please disassemble it according to the following instructions. (Note: The general consumable damage in the inner valve is the diaphragm and the round ring, and the other internal parts are rarely damaged)
1. Close the front and rear gate valves of the main valve first.
2. Loosen the piping joint screw on the main valve cover to release the pressure in the valve.
3. Remove all the screws, including the nut of the necessary copper pipe in the control pipeline.
4. Take the valve cover and spring.
5. Remove the shaft core, diaphragm, piston, etc., and do not damage the diaphragm.
6. After taking out the above items, check whether the diaphragm and round ring are damaged; if there is no damage, please do not separate the internal parts by yourself.
7. If you find that the diaphragm or circular ring is damaged, please loosen the nut on the shaft core, disassemble the diaphragm or ring gradually, and then replace it with a new diaphragm or circular ring.
8. Check in detail whether the internal valve seat and shaft core of the main valve are damaged. If there are other sundries inside the main valve, clean them out.
9. Assemble the replaced parts and components to the main valve in the reverse order. Pay attention that the valve should not be jammed.
Post time: Dec-13-2021
