This standard specifies the technical requirements, test methods and inspection rules for reversing valves used in pneumatic transmission and control systems. This standard applies to general industrial pneumatic, electric, manual and mechanical control reversing valves with compressed air as the working medium. Pneumatic reversing valves with special requirements are not covered by this standard. JB/T 6378-1992 Technical conditions for pneumatic reversing valves JB/T6378-1992 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T 6378-1992
Technical Conditions for Pneumatic Directional Control Valves
Published on July 15, 1992
Implementation by the Ministry of Machinery and Electronics Industry of the People's Republic of China on January 1, 1993
Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Pneumatic Directional Control Valves
Subject Content and Scope of Application
JB/T 63781992
This standard specifies the technical requirements, test methods and inspection rules for directional control valves used in pneumatic transmission and control systems. This standard applies to general industrial pneumatic, electric, manual and mechanical control directional control valves with compressed air as the working medium. Pneumatic directional control valves with special requirements are not covered by this standard. ：Referenced standards
GB1497
GB4026
Rated voltage
Hydraulic and pneumatic graphic symbols
Basic test methods for low-voltage electrical appliances
Basic standards for low-voltage electrical appliances
General rules for identifying electrical terminals and marking terminals with alphanumeric symbols 3 Terms, symbols, and codes
3.1 Terms
3.1.1 Pneumatic reversing valve
A pneumatic directional control valve with more than two connection ports and capable of obtaining more than two flow states. 3.1.2 Reversing
When the outlet pressure of a pneumatic reversing valve rises to 90% of the inlet pressure or drops to 10% of the inlet pressure under specified conditions, the pneumatic reversing valve is considered to have achieved reversal.
3.1.3 Reversing time
The time it takes from the start of the control signal to the reversing of the reversing valve. 3.1.4 Minimum working pressure
The minimum inlet pressure for normal reversing of pneumatic reversing valve. 3.1.5 Minimum control pressure
The minimum pressure at the control port of the valve that can make the pneumatic air-controlled reversing valve reversing normally. 3.1.6 Minimum control force
The minimum force that can make the pneumatic manual and mechanical control reversing valve reversing normally. 3.1.7 Elastic seal
The sealing form that uses the elasticity of the seal to achieve the sealing requirements. 3.1.8 Clearance seal
The sealing form that uses the matching clearance between the relative sliding parts to achieve the sealing requirements. 3.1.9
Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on July 15, 1992 and implemented on January 1, 1993
JB/T6378-1992
The phenomenon of air flowing out from the part with sealing requirements is called leakage. 3.1.10 Internal leakage
The leakage between the flow channels in the inner cavity of the pneumatic reversing valve is called internal leakage. The flow measured from the outlet of the pneumatic reversing valve that is disconnected from the inlet is the internal leakage referred to in this standard. 3.1.11 External leakage
The leakage from the inside of the pneumatic reversing valve to the atmosphere is called external leakage. 2 Working frequency
The reciprocal of the interval time between the two reversing actions of the reversing valve in the working state, expressed as 1 time/time (quantity). 3.1.13 Effective cross-sectional area (S value) under plug flow state When the element is in a vertical plug flow state, the mass flow through the element is multiplied by the square root of the upstream total temperature, and then divided by 0.0404 times the upstream total pressure. 3.1.14 Critical pressure ratio b
Based on the assumption that the flow characteristic curve of the element is a quarter ellipse under subsonic flow, the value calculated from the measured data is used to represent the ratio of the static pressure downstream of the element to the total pressure upstream when the flow becomes a vertical plug flow. 3.2 Symbols and codes
3.2.1 The graphic symbols of pneumatic reversing valves shall comply with the provisions of GB786. 3.2.2 The codes used in the graphic symbols of pneumatic reversing valves are: P for inlet, A, B, C-· for outlet, O for exhaust port, K ​​for control port, and the position number is marked with a footer, such as O, O2\, K, K,. 4 Technical requirements
4.1 Working conditions
4.1.1 Working medium
The working medium of the pneumatic reversing valve shall be filtered, dried and other treatments and meet the requirements of Table 1 Table 1
Medium requirements
Gap seal
Elastic seal
Working pressure, MPa
Allowable fluctuation
Nominal value
Note: ①Unless otherwise specified, the medium should generally contain lubricating oil mist. ②The working medium treatment procedure recommended in Appendix A (reference) can be used. Working environment
The working environment of the pneumatic reversing valve shall meet the requirements of Table 2. Table 2
Environmental requirements
Control mode
Air control, manual and machine control
Pressure dew point
Generally should be 10
lower than the temperature of the use environment
Relative humidity of surrounding air
Solid particle content
Maximum particle size
Maximum concentration
Electrical pollution level
According to GB1497
4.1.3 Installation requirements
JB/T 63781992
Pneumatic reversing valves should be installed according to the installation direction specified in the instruction manual. 4.1.4 Working frequency
The working frequency of pneumatic reversing valves should be 1 time/s~1 time/30d. 4.1.5 Power supply requirements
4.1.5.1 The power supply voltage used by the pneumatic solenoid reversing valve shall comply with the rated voltage of the reversing valve. The AC power supply frequency used by the pneumatic solenoid reversing valve is 50 (60) Hz. 4.1.5.2 The allowable power supply voltage fluctuation range of the pneumatic solenoid reversing valve is 85%~110% of the rated voltage, and the allowable power supply frequency fluctuation range is -5%~5%.
4.2 Technical performance
4.2.1 Nominal pressure
The nominal pressure of the pneumatic reversing valve shall comply with the provisions of Table 3. 4.2.2 Control performance
The control performance of the pneumatic reversing valve is shown in Table 3.
4.2.2.1 Working voltage
The pneumatic solenoid reversing valve shall be reliably reversing within the working voltage range specified in Table 3. 4.2.2.2 Solenoid release voltage
The release voltage of the solenoid of the pneumatic magnetic reversing valve shall be within the range specified in Table 3. 4.2.2.3 Minimum working pressure
The minimum working pressure of the pneumatic electromagnetic reversing valve (pilot type) shall comply with the provisions of Table 3. 4.2.2.4 Minimum control pressure
The minimum control pressure of the pneumatic air-controlled reversing valve shall comply with the provisions of Table 3. 4.2.2.5 Minimum control force
The minimum control force of the pneumatic manual and mechanical control reversing valve shall comply with the provisions of Table 3. Table 3
Control mode
Switching conditions
Nominal pressure
Working voltage
Rated value
Switching action
Electromagnet release
Discharge voltage V
85~11075~2075~10
Minimum working
(pilot type)
Minimum control
pressure
Manual, mechanical control
Minimum control force
≤100
JB/T 63781992
When the pneumatic reversing valve is switched, the action should be fast and flexible, without abnormal sound. 4.2.4 Switching time
The switching time of pneumatic reversing valve (except for manual and mechanical control) shall comply with the provisions of Table 4. Table 4
Indicator Item
Flow Characteristics
Flow Characteristics
Smin, mm?
Durability
≥150
Switching Time
Internal Leakage,
, mL/minwww.bzxz.net
Elastic Seal
≤100
The flow capacity of the pneumatic reversing valve is expressed by the effective cross-sectional area S value and the critical pressure ratio b value under the plastic plug flow state. The S value and b value of each channel of the pneumatic reversing valve shall comply with the provisions of Table 4. 4.2.6 Sealing
The sealing performance of the pneumatic reversing valve is expressed by the internal and external leakage of the reversing valve. 4.2.6.1 The internal leakage of the pneumatic reversing valve under the test pressure shall comply with the provisions of Table 4. 4.2.6.2 The pneumatic reversing valve shall have no external leakage under the test pressure. 4.2.7 Pressure resistance
The pneumatic reversing valve shall not crack, permanently deform or suffer other damage under the test pressure. 4.2.8 Durability
The durability of the pneumatic reversing valve shall comply with the requirements of Table 4. 4.2.9 Appearance quality
4.2.9.1 The appearance of the pneumatic reversing valve shall be smooth, flat and uniform in color, without any defects such as peeling, scratches or bumps. 4.2.9.2 The exposed surface of the pneumatic reversing valve shall be treated with rust prevention and other treatments, and shall comply with the relevant technical standards. 4.2.10 Electronic performance
Pneumatic solenoid directional control valves shall be subjected to electrical performance tests under specified conditions. 4
Gap sealing
≤1000
≤1500
≤2000
Power frequency withstand voltage
JB/T6378-1992
Pneumatic solenoid directional control valves shall be subjected to power frequency withstand voltage tests according to the method in Article 5.2.9.1, and the test voltage shall be in accordance with the provisions of Table 5. Table 5
Rated voltage
>60~300
>300~660
Power frequency withstand voltage test voltage
AC effective value, V
Insulation resistance
The temperature rise values ​​of the coils and electromagnets of pneumatic solenoid directional control valves measured under the conditions of Article 5.2.9.2 shall comply with the provisions of Table 6. Table 6
Insulation material grade
4.2.10.3 Resistance to moisture and heat
Temperature rise, ℃
≤110
Insulation material grade
Pneumatic solenoid directional control valves shall be subjected to alternating damp and hot environment test (Db) under the conditions of Article 5.2.9.3. 4.2.10.4 Insulation resistance
The insulation resistance of pneumatic solenoid directional control valves shall meet the requirements of Table 5 under the damp and hot conditions of Article 5.2.9.3. 4.2.10.5 Terminals
The identification and marking of the terminal of pneumatic solenoid directional control valves shall comply with the provisions of Article 7.1.6 of GB1497. 5 Test methods
5.1 Test conditions
5.1.1 Medium requirements
5.1.1.1 The test pressure of pneumatic directional control valves shall comply with the provisions of Table 7. Table 7
Test pressure
Test items
Control performance
Switching action
Switching time
Durability
Sealing
Internal leakage
External leakage
Pressure resistance
Effective cross-sectional area
Temperature rise, ℃
≤135
≤160
Allowable fluctuation, %
JB/T6378-1992
Other requirements for the test medium of pneumatic reversing valve are the same as those for the working medium. 5.1.1.2
5.1.2 Environmental requirements
5.1.2.1 Temperature
a. Type inspection: 25℃±10℃;
b. Factory inspection: at room temperature.
5.1.2.2Relative humidity shall not exceed 85%.
5.1.3Power supply requirements
5.1.3.1The error range of the test power supply voltage and the error range of the AC power supply frequency shall be -5%~5% of the rated value. 5.1.3.2The ripple factor of the test DC power supply shall not exceed 5%. 5.1.3.3The power supply used for test instruments and meters shall comply with the provisions in the manuals of each instrument and meter.
5.1.4Test device
5.1.4.1The location of the pressure measuring point in the test device shall comply with the provisions of Figure 1. ?
Medium processing system
Pressure gauge connector
Schematic diagram of the pressure gauge pipe connector (see Figure 2).
Location of pressure measuring point
Pressure outlet
Pressure sensor joint
Pressure sensor
No protrusions or hair loss
Figure 2 Schematic diagram of pressure gauge connecting pipe
Unless otherwise specified, the allowable error of the measurement value shall be as specified in Table 8. Table 8
Durability
Unit of measurement
Allowance difference (% of measured value)
Type inspection
±2℃
(0~5) %
±3℃
5.2 Test items and methods
5.2.1 Control performance
5.2.1.1 Working voltage
JB/T 6378—1992
Introduce the medium that meets the requirements of Article 5.1.1 into the inlet of the electromagnetic reversing valve under test, adjust the power supply voltage to the minimum and maximum working voltages specified in Table 3 respectively, and turn on the circuit. If the valve under test can achieve reversing at this time, the valve meets the requirements. 5.2.1.2 Solenoid release voltage
Continuously reduce the voltage of the electromagnetic reversing valve in the attracted state until the valve under test changes direction due to the release of the electromagnet. The voltage at the moment of change is the electromagnet release voltage.
The number of times and values ​​of the electromagnet release voltage should be measured in accordance with the provisions of Table 9. Table 9
Current type
Number of measurements
≥2 times
5.2.1.3 Minimum working pressure
≥6 times
Value method
Take the arithmetic mean
Electrify the solenoid valve (pilot type) under test to make it in working state. Preparation
For direct current, the polarity should be changed every time for factory inspection, and the polarity should be changed every 2 times for type inspection
Make the inlet pressure of the valve under test rise slowly until the valve changes direction. The inlet pressure of the valve at the moment of change is the minimum working pressure. The test should be conducted three times in succession and the average value should be taken.
5.2.1.4 Minimum control pressure
Introduce the medium that complies with the provisions of Article 5.1.1 at the inlet of the tested pneumatic control reversing valve, and slowly increase the pressure at the control port of the valve until the valve achieves reversal. The control port pressure at the moment of the valve reversal is the minimum control pressure. The test should be conducted three times in succession and the average value should be taken. 5.2.1.5 Minimum control force
Introduce the medium that complies with the provisions of Article 5.1.1 at the inlet of the tested human and mechanical control reversing valve, and then add a force in the same direction as the movement of the valve core at the control end of the valve, and gradually increase the force until the tested valve achieves reversal. The force received by the valve in the transient state of reversal is the minimum control force. 5.2.2 Reversing action
Introduce the medium that complies with Article 5.1.1 at the inlet of the tested valve, and give the rated reversing conditions specified in Table 3 according to its control method to make the tested valve reverse.
Make the tested valve reverse 5 times (back and forth) continuously, and observe and judge whether its reversing action is normal. If its action meets the requirements of Article 4.2.3, the reversing action can be considered normal.
5.2.3 Reversing time
Introduce the medium that meets the requirements of Article 5.1.1 into the inlet of the tested valve, and give the rated reversing conditions specified in Table 3 according to its control method, so that the tested valve is reversed, and the actual reversing time is measured. Reverse continuously 10 times (back and forth) at a frequency of 1 time/s, take the arithmetic mean, and it should meet the following formula: ITMT1/T≤30%
Where: TM—actual maximum or minimum value; T—average value.
5.2.4 Flow characteristics
JB/T6378-1992
5.2.4.1 The flow characteristics test shall be conducted between the P, A, B ports and between the A, B, O ports of the tested valve. 5.2.4.2 The flow characteristics test shall be conducted in accordance with the test methods for flow characteristics of relevant standard pneumatic components. 5.2.5 Sealing
5.2.5.1 Internal leakage
Introduce the medium that meets the requirements of Article 5.1.1 into the inlet of the tested valve, and then measure the flow of each outlet that should be isolated from the inlet at each position of the valve core. These flows are the internal leakage of each flow channel. 5.2.5.2 External leakage
Block the outlet of the tested valve, and pass the medium that meets the requirements of Article 5.1.1 into the inlet of the tested valve. Maintain the pressure for 0.5 minutes. Check with soapy water or other methods. There should be no external leakage. 5.2.6 Pressure resistance
Block the outlet of the tested valve and make the valve core in the working position. Pass the medium specified in Article 5.1.1 through the inlet of the tested valve, maintain the pressure for 1 minute, and check that each part can meet the requirements of Article 4.2.7 of this standard.
5.2.7 Durability
5.2.7.1 Pass the medium specified in Article 5.1.1 through the inlet of the tested valve, and give the reversing conditions specified in Table 3 at a frequency of 1 time/s, so that the tested valve is repeatedly reversed. When the number of reversals reaches the specified durability index, repeat the inspection of Articles 5.2.1, 5.2.2, 5.2.3, and 5.2.5, and it should still meet the corresponding regulations and requirements.
5.2.7.2 No adjustments shall be made during the durability test, but lubricant may be added after every 300,000 times; the valve under test may be cleaned or lubricated before retesting the relevant performance after the specified number of times, but parts and their assembly positions may not be replaced. 5.2.8 Appearance quality
5.2.8.1 Appearance inspection is generally carried out by visual inspection, and the inspection results shall meet the requirements of Article 4.2.9. 5.2.8.2 Surfaces treated according to standards shall comply with the test methods of the corresponding standards. 5.2.8.3 Check whether the wiring terminals are firm and easy to identify, and whether they meet the requirements of Article 4.2.10.5. 5.2.9 Electrical performance
5.2.9.1 Power frequency withstand voltage
5.2.9.1.1 The power frequency withstand voltage test voltage waveform of the pneumatic solenoid reversing valve is a sine wave with a frequency of 45~62Hz. When the high voltage output terminal is short-circuited, the current should not be less than 0.5A.
5.2.9.1.2 The power frequency withstand voltage test of the pneumatic solenoid reversing valve should be carried out between the solenoid coil and the shell of the valve under test, and the test voltage value should be selected according to Table 5 of Article 4.2.10.1.
5.2.9.1.3 Pressure application time: 1min for type inspection and can be shortened to 1s for factory inspection. 5.2.9.1.4 When applying voltage, it should start from less than 1/2 of the test voltage, gradually increase to the specified value, and then continue for the specified time. Sudden loss of pressure should be avoided at the end of pressure application.
5.2.9.1.5 Qualification judgment: There should be no insulation breakdown and flashover 5.2.9.1.6 The rest can be in accordance with the provisions of Article 8.2.2.3.2 of GB1497. 5.2.9.2 Temperature rise
5.2.9.2.1 The temperature rise test of the coil and electromagnet of the pneumatic electromagnetic reversing valve shall be carried out at the rated frequency and rated voltage. The ambient air temperature is 10~40℃, and the ambient air temperature change during the test shall not exceed 10℃. 8
JB/T 63781992
5.2.9.2.2 The temperature rise value must be measured under the stable heating state (when the temperature rise difference measured at an interval of 1h does not exceed 1℃, the heating is considered stable).
5.2.9.2.3 The remaining temperature rise test methods shall comply with the provisions of Article 5.3 of GB998. 5.2.9.3 Moisture and heat resistance
The moisture and heat resistance test of the pneumatic electromagnetic reversing valve shall be carried out under the following conditions in accordance with the method specified in Article 7.2.13.2 of GB1497. a. Severe level: high temperature is 55℃, test cycle is 2 days and nights; b. In the last 1~2h of low temperature and high humidity stage, measure the insulation resistance between the electromagnetic coil and the shell of the valve within 3min, and then conduct 1min power frequency withstand voltage test;
c. The measured insulation resistance should not be less than the provisions of Table 5. The measuring instrument of insulation resistance should be selected according to Table 10. The test voltage of power frequency withstand voltage is 80% of the value specified in Table 5.
Rated voltage
>60~380
6 Inspection rules
6.1 Factory inspection
Pneumatic reversing valves must be inspected and qualified by the quality inspection department before they can be shipped. Voltage level of megohmmeter
The items of factory inspection of pneumatic reversing valves are divided into two categories: mandatory inspection and random inspection according to the provisions of Table 11. Table 11
Inspection items
Working voltage
Release voltage
Minimum working pressure
Minimum control pressure
Minimum control force
Switching action
Sealing
Appearance quality
Power frequency withstand voltage
Pressure resistance
Inspection category
Solenoid reversing valve
Solenoid reversing valve (pilot type)
Pneumatic reversing valve
Manpower and mechanical control reversing valve
For electromagnetic reversing valve
The sampling inspection items should be selected from the products with all qualified mandatory inspection items at a ratio of 2%, and shall not be less than 3 pieces. Judgment rules
a. If any mandatory inspection item does not meet the requirements, the product is unqualified; b. If all mandatory inspection and sampling inspection items meet the requirements, the product is qualified; c. If there are unqualified items in the random inspection, the unqualified items should be double sampled in the same inspection batch. If all the re-inspected products meet the requirements of 9
JB/T6378-1992
, the products in the batch except those that failed the first inspection are considered qualified; d. If there are still unqualified items in the re-inspection, the items of the batch of products should be inspected piece by piece. 6.2 Type inspection
6.2.1 Type inspection should be carried out in any of the following situations: a. Product trial design and identification;
b. When the product performance may be affected due to improved design, changed process or material; c. Large-volume products, not less than once every three years; d. Products that have been suspended for more than one year and then resumed production; e: When the factory inspection results are significantly different from the last type inspection; f. When the quality supervision agency puts forward type inspection requirements. 6.2.2
The number of samples used for type inspection shall not be less than 3. One of the samples shall be inspected for all items, and the other two shall be inspected for all items except durability.
6.2.3 Judgment Rules
a. If all the sample inspections meet the requirements, the product type inspection is qualified; b. If one performance item of the sample fails, the item shall be double sampled for re-inspection. If all the re-inspected samples meet the requirements, the product can still be judged as qualified except for the ones that failed the first inspection; c. If there are still unqualified ones after the re-inspection, the product type inspection is judged to be unqualified. After sorting and judging the inspection results, fill in the corresponding inspection report. 6.2.42
The number of samples used for type inspection shall not be less than 3. One of them shall be inspected for all items, and the other two shall be inspected for all items except durability.
6.2.3 Judgment rules
a. If all the sample inspections meet the requirements, the product type inspection is qualified; b. If one performance item of the sample fails, the item shall be double sampled for re-inspection. If all the re-inspected samples meet the requirements, the product can still be judged as qualified except for the samples that failed the first inspection; c. If there are still samples that fail the re-inspection, the product type inspection is judged to be unqualified. After sorting and judging the inspection results, fill in the corresponding inspection report. 6.2.42
The number of samples used for type inspection shall not be less than 3. One of them shall be inspected for all items, and the other two shall be inspected for all items except durability.
6.2.3 Judgment rules
a. If all the sample inspections meet the requirements, the product type inspection is qualified; b. If one performance item of the sample fails, the item shall be double sampled for re-inspection. If all the re-inspected samples meet the requirements, the product can still be judged as qualified except for the samples that failed the first inspection; c. If there are still samples that fail the re-inspection, the product type inspection is judged to be unqualified. After sorting and judging the inspection results, fill in the corresponding inspection report. 6.2.4
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