Some standard content:
Scope of application
National Standard of the People's Republic of China
Directional control valve
Test method
Hydraulic fluid power-Valves-Testing method of directfonal control valvesUDC 621. 646. 001, 4
GB 8106—87
This standard applies to the steady-state performance and transient performance tests of directional control valves using hydraulic oil (liquid) as the working medium. The test method standards for proportional control valves and electro-hydraulic servo valves are specified separately. 2 Symbols, dimensions and units
Symbols, dimensions and units are shown in Table 1. Www.bzxZ.net
Symbols, dimensions and units
Nominal diameter of valve
Linear displacement of control element in valve
Angular displacement of control element in valve
Volume flow rate
Inner diameter of pipe
Anti-stress, pressure difference
Mass density of oil
Kinematic viscosity
Celsius temperature
Equal volume elastic modulus
-Mass-L-
3 General rules
3.1 Test apparatus
3.1.1 Test loop
Length IT--time;6
Temperature.
ML-IT-2
MI-IT-2
3.1.1.1 Figures 1, 8, 10 and 11 are basic test circuits. It is allowed to use a comprehensive circuit including two or more test conditions. 3.7.1.2 The flow rate of the oil source should be adjustable. The flow rate of the oil source should be greater than the nominal flow rate of the test valve. The pressure pulsation of the oil source shall not be greater than ±0.5MPa.
3.1.1.3 It is allowed to add pressure and flow regulating elements to the given basic test circuit to ensure the safe operation of the test system. 3.1.1.4 The inner diameter of the pipes and pipe joints connected to the test valve should be consistent with the nominal diameter of the test valve. Approved by the State Machinery Industry Commission on July 13, 1987 and implemented on July 1, 1988
3. 1. 2 Position of pressure measuring points
3.1.2.1 Position of inlet pressure measuring points
GB 8106-87
The inlet pressure measuring point should be set between the downstream of the disturbance source (such as valve, elbow) and the upstream of the test valve. The distance from the disturbance source should be greater than 10d, and the distance from the test valve is 5t.
3.1.2.2 Location of outlet pressure measuring point
The inlet pressure measuring point should be located 1(0d downstream of the test valve. 3.1.2.3 When testing according to Class C accuracy, if the location of the pressure measuring point does not meet the above requirements, the corresponding correction value should be given. 3.1.3 Pressure measuring hole
3.1.3.1 The diameter of the pressure measuring hole shall not be less than 1mm and shall not be greater than 6mm. 3.1.3.2 The length of the pressure measuring hole shall not be less than 2 times the diameter of the pressure measuring hole. 3.1.3.3 The center line of the pressure measuring hole is perpendicular to the center line of the pipeline. The intersection of the inner surface of the pipeline and the pressure measuring hole should be sharp, but without burrs. 3.1.3.4 The inner diameter of the connecting pipe between the pressure measuring point and the measuring instrument shall not be less than 3mm. 3.1.3.5 When the pressure measuring point is connected to the measuring instrument, the air in the connecting pipe should be removed. 3. 1. 4 Position of temperature measurement point
The temperature measurement point should be set 15d upstream of the inlet pressure measuring point of the tested valve. 3.1.5 Solid contamination level of oil
3.1.5.1 In the test system, the solid contamination level of the hydraulic oil (liquid) used shall not be higher than 19/16. Other provisions may be made when there are special test requirements.
3.1.5.2: During the test, if the values measured for the same parameter are inconsistent due to clogging within a certain time interval, the filter's filtration accuracy should be improved. 3.1.5.3 Indicate the installation location, type and number of filters in the test report. 3.1.5.4 Indicate the solid contamination level of the oil in the test report and the method for determining the contamination level. 3.2 General requirements for testing
3.2.1 Test oil
3.2.1.1 Indicate the type and brand of oil used in the test as well as the viscosity, density and bulk elastic modulus of the oil at the test control temperature in the test report. ||tt ||3.2.1.2 When measuring the effect of different oil viscosities on the test at the same temperature, use the same type of oil with different viscosities. 3.2.2 Test temperature
3.2.2.1 When testing components with hydraulic oil as the working medium, the oil temperature at the inlet of the tested valve is 50°C. When other oils are used as the working medium or there are special requirements, other regulations may be made and the actual test temperature shall be noted in the test report. 3.2.2.2 During the cold start test, the oil temperature shall be lower than 25°C. Before the test begins, turn off the test equipment and oil. The temperature of the fluid is maintained at a certain temperature. The temperature of the fluid is allowed to rise after the test begins. The relationship between temperature, pressure and flow rate and time is recorded in the test report. 3.2.3 Steady-state conditions
3.2.3.1 Steady-state conditions are when the controlled parameters change within the range specified in Table 2. Record the measured values of the test parameters under steady-state conditions. Table 2 Allowable range of variation of the average indicated value of the controlled parameters Controlled number
Flow rate, %
Pressure, %
Temperature.℃
Viscosity, %
±5- 0
Test level
3.2.3.2 The number of measurement reading points of the measured parameters and the distribution of the readings taken should be able to reflect the performance of the valve under test in the full range. 3.2.3.3 In order to ensure the repeatability of the test results, the time interval of measurement should be specified. 3.3 Pressure test
GB 8106—87
3.3.1 The pressure test should be carried out before the valve under test. 3.3.2 During the pressure test, the pressure test pressure is applied to each pressure-bearing oil port. The pressure test pressure is that the oil increases at a rate of 2% of the pressure test pressure per second, and the pressure is maintained for 5 minutes. There shall be no external leakage. 3.3.3 During the pressure test, each oil drain port is connected to the oil tank. 4 Test content
4.1 Directional valve
4.1.1 Solenoid directional valve
4.1.1.1 Test circuit
The typical test circuit is shown in Figure 1.
In order to reduce the pressure shock during the test of the directional valve, it is allowed to be operated without changing the test conditions.
In order to protect the flow meter 10, the valve 8d can be opened when not measuring. 4.1.1.2 Steady-state pressure difference-flow characteristic test The test is carried out in accordance with the relevant provisions of GB8107 "Test method for pressure difference-flow characteristic of hydraulic valve". The steady-state pressure difference-flow characteristic curve between the ports is shown in Figure 2. 4.1.1.3 Internal leakage test
a. Test purpose
This test is to determine the pressure difference and the inconsistency between the pressure difference and the flow rate when the directional valve is in a certain working state.
b, Test conditions
During the test, the pressure applied to each oil port should be consistent and recorded. c Test method
GB 8106-87
When the temperature of the electromagnet meets the requirements, the voltage of the electromagnet wire diagram is 10% lower than the rated voltage during the test. Put the test valve in a certain on-off state, fully open the pressure valve 3c (or 3a), make the indicated pressure of the pressure gauge 5b (or 5c) the minimum load pressure, and gradually increase the flow through the test valve from small to a certain specified maximum flow value. Record the indicated pressure of the pressure gauge 5a corresponding to each flow rate. Draw the curve 0D shown in Figure 6 on the rectangular coordinate paper. Adjust the pressure valves 3a and 3c (or 3d) so that the indicated pressure of the pressure gauge 5a is the nominal pressure of the test valve. Gradually increase the flow through the test valve to make the reversing valve reversing. When a certain flow rate is reached and the reversing valve cannot be normally reversed, reduce the indicated pressure of the pressure gauge 5a until it can be normally reversed. Test in this way until a certain specified flow rate is reached. Draw the curve ABC on the same coordinate paper. The area included in the curve ABCDO is the working range in which the electromagnetic reversing valve can stop normal reversing. Curve BC is the switching valve of the reversing valve. Determine the boundary value of the working range of the reversing valve from the data obtained from the repeated test. The number of repeated tests shall not be less than 6 times. 4.1.1.5 Transient response test
Test month
This test is to test the transient response characteristics of the electromagnetic reversing valve when reversing. b.． Test conditions
The circuit volume on the output side of the tested valve shall be a closed volume and filled with oil before the test. Record the size of the closed volume, the cavity and the material of the pipeline in the test report.
The test shall be carried out at the rated voltage of the electromagnet and the electromagnet temperature specified in 4.1.1.4. Test method
Adjust the pressure valve 3a and 3c (or 3d),Make the indicated pressure of the pressure gauge 5a the test pressure of the test valve, and adjust the flow rate so that the flow rate through the test valve is 8% of the corresponding flow rate on the conversion valve under the nominal pressure. After adjustment, turn on or off the control voltage of the electromagnet. Determine the lag time t and t, and the response time t and t from the transient response curve representing the response of the valve core displacement of the reversing valve to the reversing signal applied to the electromagnet, as shown in Figure 7a. Determine the lag time t, and, and the response time t and t from the transient response curve representing the response of the pressure change at the output port of the reversing valve to the reversing signal applied to the electromagnet, as shown in Figure 7b. 4.1.2 Electro-hydraulic reversing valve, hydraulic reversing valve, manual reversing valve, motorized reversing valve 4.1.2.1 Test circuit
The typical test circuit is shown in Figure 8. 1a is the main circuit oil source, and 1b is the control circuit oil source. See 4.1.1.1 for the rest of the test circuit requirements. 4.1.2.2 Steady-state differential pressure-flow characteristic test Same as electromagnetic reversing valve. See 4.1.1.2.
4.1.2.3 Internal leakage test
Same as electromagnetic reversing valve. See 4.1.1.3.
4.1.2.4 Working range
a, Test purpose
This test is to determine the boundary value range of the minimum control pressure when the electro-hydraulic reversing valve and hydraulic reversing valve can be normally reversing. Determine the boundary value range of the minimum control force when the manual reversing valve and motorized reversing valve can be normally reversing. Note: Normal reversing means that after the reversing signal is issued, the reversing valve core can move in the full stroke in both directions of displacement. b, Test conditions
Same as electromagnetic reversing valve. See 4.1.1.4
c. Test method
The test is conducted within the nominal pressure and nominal flow range of the test valve. Record the pressure and flow range values used in the test in the test report.
GB 810687
Adjust the pressure valves 3a and 3c (or 3d) so that the indicated pressure of the pressure gauge 5a is the nominal pressure. Determine the minimum control force or minimum control force of the test valve when passing different flow rates. Draw the working range curve on the rectangular coordinate system, see Figure 9 (when the control pressure or control force of the test valve is greater than or equal to the minimum control pressure or minimum control force, the test valve can be normally switched). For electro-hydraulic directional valves, when the solenoid temperature meets the requirements, the solenoid coil voltage is 10% lower than the rated voltage during the test. For hydraulic directional valves, one or two of the following tests are carried out according to regulations: A. Increase the control pressure step by step, and the incremental rate shall not exceed 2% of the nominal pressure of the main valve per second. B. Increase the control pressure in a cascade manner, and its slope shall not be less than 700MPa8-1. From the data obtained from the repeated tests, determine the boundary value range of the minimum control pressure or minimum control force of the valve. The number of repeated tests shall not be less than 6 times.
4.1.2.5 Transient response test
． Test purpose
This test is to determine the transient response characteristics of the main valve of the electro-hydraulic directional control valve and hydraulic directional control valve when changing direction. b. Test conditions
The circuit volume on the output side of the test valve should be a closed volume and filled with oil before the test. Record the size of the closed volume and the material of the cavity and pipeline in the test report.
For electro-hydraulic directional control valves, the test is carried out under the conditions of the rated voltage of the electromagnet and the electromagnet temperature specified in 4.1.1.4. For hydraulic directional control valves, the rate of change of the pressure in the control circuit should be able to cause the hydraulic valve to operate quickly. C. Test method
Adjust the pressure valves 3a and 3c (or 3b) so that the indicated pressure of the pressure gauge 5a is the nominal pressure of the test valve, and the flow rate is the nominal flow rate of the test valve, so that the reversing valve is reversed.
Record the response curve of the valve core displacement or output pressure, and determine the hysteresis time and response time (see the provisions of Figure 7 in 4.1.1.5). 4.2 Check valve
4.2.1 Test circuit
4.2.1.1 See Figure 10 for the test circuit of direct-acting check valve. See Figure 11 for the test circuit of hydraulic control check valve. When the flow direction is from port A to port B, the test is carried out with or without pressure applied to the control oil port X. When the flow direction is from port B to port A, the test is carried out with control pressure applied to the control oil port. 4.2.2 Steady-state differential pressure-flow characteristic test
The test is carried out in accordance with the relevant provisions of GB8107, and the steady-state differential pressure-flow characteristic curve is drawn, as shown in Figure 12.4.2.3 Test of minimum opening force Pomin of direct-acting check valve The purpose of this test is to determine the minimum opening force Pomi of the test valve. When the pressure of the test valve 2b is atmospheric pressure, the pressure a at port A is gradually increased from zero until oil flows out. Record the pressure value at this time and repeat the test several times. The minimum opening pressure Pania of the valve is determined from the test data. 4.2.4 Hydraulic control check valve control pressure P test. 4.2.4.1 Test and
This test is to test the minimum control repulsion force required to open the hydraulic control check valve and keep it fully open. Test the maximum control pressure Px of the hydraulic control check valve to close the valve within the specified pressure a and flow 4 range. 4.2.4.2 Test method
When the hydraulic control check valve is not opened in the reverse direction, it is kept at a certain value (pumx, 0.75pBimx, 0.5Praax.25PBua and PBai) within the specified pr range, and the control repulsion force x is gradually increased from zero until the flow through the hydraulic control check valve in the reverse direction reaches the selected flow y value:
Record the control pressure x and the corresponding flow 9, and repeat the test several times. Determine the minimum control pressure Px when the valve is opened and passes the selected flow g value from the recorded data. Draw the relationship curve between the valve opening pressure Pxo and the flow 4. See Figure 13. GB 8106-87
Apply the control pressure Px to the control oil port X to ensure that the tested valve is in a fully open state, so that the output value is as low as possible, select a certain flow 9, pass through the tested valve, and gradually reduce the force x value until the check valve is completely closed. Record the control pressure x and flow 9, and repeat the test several times. The maximum control pressure xc- that makes the valve close is determined by the recorded data. Draw the relationship curve between the closing pressure pxc-flow rate q of the hydraulic control check valve, see Figure 14. 4.2.5 Leakage test
The measurement time of the leakage test should last at least 5tmin. The test report should indicate the oil temperature, oil type, brand and viscosity during the test. 4.2.5.1 When testing a direct-acting check valve
, the test valve should be installed in reverse. Port A is at atmospheric pressure, and port B is connected to the specified pressure value. Within a certain time interval (at least 5min), measure the leakage outflowing from port A, and record the measurement time interval value, leakage amount and value. 4.2.5.2 Hydraulic control check valve
Port A and port X are at atmospheric pressure, and port B is connected to the specified pressure value. Within a certain time interval (at least 5min), measure the leakage outflowing from port A. Record the measurement time interval value, leakage amount and value. This method is also suitable for measuring the leakage outflowing from leakage port Y. 5 Test Report
5.1 The information on the tested valve and test conditions shall at least include the following items and shall be clearly stated in the test report: a.
Manufacturer name:
Product name and specifications (model, serial number, etc.);
Manufacturer’s instructions on the valve;
Detailed list of connecting pipes and pipe joints:
Manufacturer’s requirements on filtration;
Accuracy level of the filter in the circuit,
Actual solid contamination level of the test oil; Test oil (brand description);| |tt||Kinematic viscosity of the test oil:
Density of the test oil:
Equivalent bulk elastic modulus of the test oil
Temperature of the test oil;
Ambient temperature;
Maximum continuous working pressure
Maximum flow rate allowed for the test;
Maximum and minimum control pressures of electro-hydraulic directional valves and hydraulic directional valves:; Control force of manual directional valves and motorized directional valves: Maximum and minimum control pressures of wave-controlled check valves, special requirements, such as: restrictions on the installation position. 5.2 Test results
List all test results in a table in the test report and draw a curve. 5.2.1 Proof pressure (for all valve types)
Record the proof pressure value.
5.2.2 Directional valve
Steady-state differential pressure-flow characteristic curve (see Figure 2); b.
Internal leakage curve (see Figure 3):
Working range curve (see Figure 6. Figure 9)
Transient response curve (see Figure 7).
5.2.3 Check valve
GB 8106-87
Steady-state differential pressure-flow characteristic curve (see Figure 12): Minimum opening pressure of direct-acting check valve; Control pressure Px-flow of hydraulically controlled check valve 4.Characteristic curve (see Figure 13, Figure 14); leakage.
Figure 1 Solenoid reversing valve test circuit
【Pressure reducing source, 2-filter, 3-lift valve: 4--Thermometer: 5 Pressure gauge! 6 Test valve 7 Accumulator, 8-stop valve: 9-pressure gauge switch: 10-flow meter; 11 Check valve outlet
GB 8106-87
Figure 2 Steady-state pressure difference flow characteristic curve
Internal leakage curve
Volume flow
Two-position two-way
OP type four-way
P type five-way
GB 8106—87
Figure 4 Schematic diagram of internal leakage test
Two-position four-way
O-type five-way
C-type four-way
GB8106-87
Electromagnetic absorption
Ambient temperature
Figure 5 Electromagnetic temperature rise curve
Figure 6 Working range curve of solenoid valve
Time (1h)
Volume flow rate Q
GB 8106-87
5% of the whole range
% of the whole range
Core displacement-time relationship curve
5% of the whole range
% of the whole range
b Pressure-time relationship curve
Figure? Transient response curve of reversing valve
Full-stroke driving
5% of full-stroke
% of full-stroke
5% of full-stroke
GB8106-
Control circuit
Figure 8 Test circuit of electro-hydraulic reversing valve, hydraulic reversing valve and manual reversing valve 1—hydraulic source, 2 filter; 3—relief valve, 4-thermometer, 5-pressure gauge: 6 test valve: 7—accumulator; 8 stop valve: 9 pressure gauge switch: 10--flow meter; 11-check valve; 12-throttle valve
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