JB/T 7069-1993 Test Guidelines for Pressure Relief Valves for Transformers
Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T7069-1993
Test Guidelines for Pressure Relief Valves for Transformers
Published on October 8, 1993
Implemented on January 1, 1994
Mechanical Industry Standard of the People's Republic of China
Test Guidelines for Pressure Relief Valves for Transformers
1 Subject Content and Scope of Application
JB/T7069-1993
This standard specifies the methods for factory test, type test and special test of pressure relief valves for transformers (hereinafter referred to as relief valves). This standard applies to factory test, type test and special test of relief valves. 2 Reference standards
GB1690
GB2423.17
GB4208
Test procedures
3.1 Factory test
Rubber Shore A hardness test method
Vulcanized rubber liquid resistance test method
Basic environmental test procedures for electrical and electronic products Test Db: Alternating damp heat test method Basic environmental test procedures for electrical and electronic products Test Ka: Salt spray test method Enclosure protection level
Opening pressure test
Closing pressure test
Time-dependent opening performance test
Signal switch insulation performance test
Opening time test||t t||Sealing performance test of sealing pressure value
3.2 Type test
All factory tests
High temperature opening performance test
Low temperature opening performance test
Vacuum sealing performance test
Displacement performance test
500 times action reliability test
Oil resistance and aging resistance test of sealing ring
Protection performance test
3.3 Special test: moisture and salt resistance test (when transformer has this requirement) 4 Main equipment and process
4.1 Compressed air for test
4.1.1 The outlet pressure of air compressor should be set between 400 and 500 kPa. 4.1, 2 There should be a gas storage tank between the air compressor and the test tank of the release valve, and the volume of the gas storage end should not be less than 200L. (If the gas source is stable, the pressure and flow can fully meet the use requirements, this gas storage tank can also be omitted). 4.2 Test pressure gauge
Approved by the Ministry of Machinery Industry on October 8, 1993
Implemented on January 1, 1994
JB/T7069-1993
4.2.1 The measuring range is 0~0.1MPa, and the accuracy is not less than Class 1.5.4.2.2 The installation position of the pressure gauge is not affected by the vibration. 4.3 Opening pressure test tank
4.3.1 Opening pressure test tank is suitable for the tests of normal temperature, high temperature, low temperature, aging and 500 times reliability opening pressure. 4.3.2 The volume of the open pressure test tank shall comply with the provisions of Table 1. Table 1
Effective diameter of oil injection
Volume of open pressure test tank
4.3.3 The pressure test strength of the open pressure test tank shall not be less than 0.3MPa. The test tank shall be equipped with 3 air nozzles (inlet, outlet, pressure gauge), and a quick-fit clamp or flange shall be installed on the upper part.
4.4 Closed pressure test
4.4.1 The closed pressure test tank is tested for the closed pressure of the release valve with a diameter of Φ130mm or less and different pressure levels. 4.4.2 The volume of the closed pressure test tank shall comply with the provisions of Table 2. The pressure test strength of the test tank shall not be less than 0.3MPa, and a quick-fit clamp or flange shall be installed on the upper part of the test.
Effective diameter of oil injection
4.5 Sealing pressure test device
4.5.1 The test device shall ensure that each test product has an independent sealing control system. 4.5.2 The pressure source used in the test system should be fixed. 4.5.3 The pressure test strength of the pressure stabilization and sealing pressure test device shall not be less than 0.3MPa, 4.6 Opening time measurement chain
4.6.1 The pressure test strength shall not be less than 0.8MPa, and the volume shall be about 8L. Close the pressure test volume
4.6.2 The test tank shall be equipped with a pressure gauge, vacuum gauge, air inlet and outlet nozzles, pressure sensor and ignition nozzle, or a transformer short-circuit test device shall be used for testing.
4.7 Displacement test system
The test system consists of a pressurized tank, a flow meter, a special test device, a pressure measuring instrument, a collection device, etc. 5 Test method
5.1 Opening pressure test
5.1.1 The normal temperature opening pressure test refers to the normal temperature, aging, and 500 times reliability opening pressure test. 5.1.2 According to the release aperture, select the test end according to the provisions of Table 1. 5.1.3 Install the release valve on the opening pressure test, fill the medium with compressed air under temperature, adjust the air intake, and when the pressure increment of the air intake is 25-40kPa/s, the release valve should jump continuously and intermittently, with a cycle of 1-4s. The signal switch should switch and self-lock each time it jumps, and the mechanical signal mark should also move obviously. It should be able to correctly judge that the release valve has been actuated. After each action, it must be manually reset. The opening pressure should comply with the provisions of Table 3.
Opening pressure
Opening pressure adjustment
Closing pressure is not less than
Sealing pressure is not less than
5.2 Closing pressure test
JB/T7069—1993
5.2.1 Install the release valve on the closing pressure test tank, open the air intake, and the pressure in the end begins to rise. When the release valve jumps, immediately close the air intake. Since the pressure in the tank is still greater than the closing pressure of the release valve, the release valve closes slowly. When the pressure gauge pointer stops completely, it means that the release valve is completely closed. The pressure gauge indication at this time is the closing pressure value of the release valve. The closing pressure should comply with the provisions of Table 3. The test should be carried out for no less than 3 times, and the lowest value should be taken as the closing pressure value of the release valve. 5.3 High-voltage opening performance test
5.3.1 Start the thermostat, adjust the control temperature to 95℃, and close the door. When the temperature in the box reaches 95℃, place the test tank with the release valve in the box. When the temperature reaches 95℃ again and remains for 30 minutes, take out the test tank and install the pressure gauge. Fill the tank with compressed air, and the pressure increment is 25~40ka/s. When the pressure in the tank reaches the opening pressure, the release valve should open, with intermittent beating, and the mechanical signs and signal switches should operate normally. It is qualified if there is no abnormality after 10 operations. All tests should not exceed 2 minutes. 5.4 Low temperature opening pressure test
5.4.1 The release valve that has passed the normal temperature, aging and high temperature opening pressure tests needs to be left to stand for 24 hours or more before the low temperature opening pressure test can be carried out. 5.4.2 Automatic low temperature box, adjust the control temperature to -30℃ and close the box door. When the temperature in the box reaches -30℃, place the test tank with the release valve in the constant overflow box. When the temperature reaches -30℃ again and is maintained for 30 minutes, take out the test tank and install the pressure gauge, fill the tank with compressed air, and the pressure increment is 2540kPa/s. When the pressure in the tank reaches the opening pressure, the release valve should open and jump intermittently. The machine domain signs and signal switches should operate normally, and it is qualified if there is no abnormality after 10 operations. All tests should not exceed 2 minutes. 5.5 Time-dependent opening performance test
5.5.1 The qualified release valve at room temperature shall be left to stand for at least 24 hours or more (the sign post with the engine core signal shall be reset). The first action pressure value measured in the test shall comply with the provisions of Table 3. The test method is the same as the opening pressure test. 5.6 Sealing pressure value sealing performance test
5.6.1 Only the release valve that has passed the overflow and time-dependent opening pressure test can be subjected to the sealing pressure test (during type test). 5.6.2 The release valve card is mounted on the test system. The system is filled with transformer oil (oil temperature is 95℃) or kerosene at room temperature. The sealing pressure value is applied to the system. The sealing pressure shall comply with the provisions of Table 3. 5.6.3 Observe the indication of the pressure gauge. When the requirement is met, start timing. After 2 hours, it is qualified if there is no leakage. 5.7 Vacuum sealing performance test
5.7.1 The vacuum system consists of a vacuum pump, a vacuum gauge with corresponding resolution, and a vacuum pump. 5.7.2 The leakage rate of the vacuum system itself should be lower than 0.1Ps·L/s. 5.7.3 Install the release valve on the vacuum pump, start the vacuum pump, adjust the vacuum, and when the vacuum residual pressure is no more than 133Pa, close the vacuum valve. When the vacuum gauge value returns to 133Pa, start timing. The leakage rate after 10 minutes should not exceed 1.33Pa·L/s, and the components should not be damaged or deformed.
The leakage rate is calculated by the following formula:
P=(P,-P,) L
Where: P,—residual pressure of vacuum, kPa; P: pressure after -10 minutes, kPa; wwW.bzxz.Net
L—effective volume, L;
tTime, s.
5.8 Sealing diagram Oil resistance and aging resistance test
JB/T7069-1993
The test method is carried out in accordance with the provisions of GB531 and GB1690 standards. 5.9500 times action reliability test
The test system composition is basically the same as the opening pressure test system, only one counter is added, and the test method is the same as 5.1. Keep the release valve constantly beating, and open the pressure gauge every 50 times to observe the change of the opening pressure. The opening pressure after 500 times should meet the requirements of Table 3.
5.10 Signal switch insulation performance test
5.10.1 The test system consists of a power frequency withstand voltage test machine. 5.10.2 Signal switch contact test, put the power frequency withstand voltage test machine in working state, the contact is in the open position, and one of the contact terminals is grounded (including the lead wire). A short-term power voltage of 2000V is applied between the contacts for 1 minute. There should be no flashover or breakdown. 5.10.3 Test of contact terminals to ground: After both sets of terminals are short-circuited, a short-time working voltage of 2000V is applied between the terminals and the ground (or the shell) for 1ma. No flashover or breakdown should occur. 5.11 Opening time test
5.11.1 The test system consists of a test tank, an ignition device, a pressure sensor, a signal preamplifier, and a fast Fourier transform analyzer (or other instruments).
5.11.2 Install the release valve on the test tank and connect the electrical circuit. 5.11.3 After the test tank is evacuated to a certain amount, turn off the vacuum pump, quickly fill the tank with prepared hydrogen, close the air inlet valve, and detonate the mixed gas to simulate a short-circuit accident. The entire action process of the pressure in the tank can be recorded by the pressure sensor, signal preamplifier, and analyzer. Repeat the above test three times to ensure that at least two release valves have an opening time of no more than 2ms to pass. 5.12 Displacement performance test
5.12.1 Install the release valve on a special test device, and measure the actual displacement of the release valve when the fluid is opened at different boost speeds under normal temperature conditions.
5.12.2 Draw a function curve of displacement and boost speed based on the test results to verify the maximum and minimum discharge volumes specified in the technical conditions. 5.13 Protection performance test
The protection performance test shall be carried out in accordance with the provisions of GB4208. 5.14 Moisture-proof test and salt spray test
5.14.1 The moisture-proof test shall be carried out in accordance with the provisions of GB2423.4. 5.14.2 The salt spray test shall be carried out in accordance with the provisions of GB2423.17. Additional notes:
This standard was proposed and managed by the Shenyang Transformer Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Shenyang Transformer Research Institute. The main drafters of this standard are Mu Chuanshi, Wang Xinjian, and Tong Qing
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