QC/T 809-2009Gas injectors for gas-fuelled vehicles (English PDF)

3.11 Fuel flow error variability

In a pulse width, the ratio OF difference BETWEEN a nozzle's flow AND the flow average value of the nozzle group within this pulse width TO the average value.

4.1 General requirements

4.1.1 The nozzle shall be manufactured according to the product drawings and technical documents that are approved by the specified procedure.

4.1.2 The rated voltage of the nozzle is DC 12V or DC 24V.

4.1.3 Minimum opening voltage. the minimum opening voltage, for DC 12V rated voltage, is DC 6V; and the minimum opening voltage, for DC 24V rated voltage, is DC 12V.

4.1.4 Maximum working voltage. the maximum working voltage, for DC 12V rated voltage, is DC 18V; and the maximum working voltage, for DC 24V rated voltage, is DC 36V.

4.1.5 When in power failure, the nozzle is in closing state.

4.1.6 The splash-proof performance of the nozzle shall conform to the regulations of GB/T 4942.2.

4.1.7 The material used for manufacturing nozzle shall be compatible with the fuel used.

4.1.8 The outer surface of the nozzle shall be smooth, without any scratching, etc.

4.2 Performance requirements

4.2.1 Pressure resistance. when the pressure resistance test is carried out according to the test method in 5.3, the leakage or crack is allowed; however, the fracture is not allowed before the leakage.

4.2.8 Temperature resistance. when it is tested according to the test method in 5.10, it shall conform to the requirement of 4.2.4.

4.2.10 Ozone resistance. after the rubber part in the nozzle is tested according to the test method in 5.12, there is no crack.

4.2.11 Compatibility. after the nonmetal part in the nozzle is tested according to the test method in 5.13, the volume change rate is not greater than 20%; and the mass decrease rate is not greater than 5%.

4.2.12 Vibration resistance. after it is subjected to 6h of vibration test according to the test method in 5.14, it shall conform to the requirements of 4.2.3.1, 4.2.3.2, 4.2.4.1 and 4.2.6.1.

4.2.2 Electrical characteristics parameters

4.2.2.1 Minimum opening voltage. when it is tested according to the test method in 5.4.1, it shall work normally, without abnormal sound.

4.2.2.2 Maximum working voltage. when it is tested according to the test method in 5.4.2, it shall work normally, without abnormal sound.

4.2.2.3 Maximum response frequency. when it is tested according to the test method in 5.4.3, it must conform to the regulation of product standards of manufacturer. to the requirements of 4.2.3.1, 4.2.3.2 and 4.2.4.1.

4.2.9 Corrosion resistance

4.2.9.1 After the brazen part in nozzle is tested according to the test method in 5.11.1, there is no obvious damage.

4.2.9.2 After it is tested according to the test method in 5.11.2, it must conform to the requirement of 4.2.4.1.

5.1 Test condition and instrument accuracy

5.1.1 Test condition. unless otherwise specified, the test environment condition and test medium shall conform to the following requirements.

a) Test environment temperature. 15 ~ 35°C;

b) Relative humidity is not greater than 85%;

c) The pressure is 86-106kPa;

d) The medium shall adopt clean dry-air or nitrogen.

5.1.2 Accuracy and range of test instrument. unless otherwise specified, the accuracy and range of the instrument shall conform to the following regulations.

a) Electrotechnical instrument. the accuracy is not lower than level-1.0, the range shall be 1.5 ~ 3 times of the measuring value;

b) Pressure instrument. the accuracy is not lower than level-1.5, the range shall be 1.5

5.6 Leakage test

The sample inlet is connected with the pneumatic supply by the shut-off valve; the pressure meter or leakage rate testing instrument is installed between the sample and the positive shut-off valve; fill the test gas with rated working pressure into the sample. After the temperature reaches to the test temperature, the positive shut-off valve is closed; the value of the pressure meter within 1min is checked, or 1min leakage rate is measured.

The leakage test shall be subjected to external leakage test and internal leakage test.

a) External leakage test. the sample outlet is sealed; and the rated power connected with the nozzle is turned on.

b) Internal leakage test. the sample outlet is opened; and the nozzle is not connected with the power.

5.6.1 Normal temperature leakage test. the test temperature is the environment temperature. 15 ~ 35°C;

5.6.2 High temperature leakage test. the test temperature is the high temperature. 120±2°C;

5.6.3 Low temperature leakage test. the test temperature is the low temperature. -40±2°C.

5.7 Drop test

The nozzle falls to the cement ground vertically and freely from 1m of elevation; and then the work characteristic test of the nozzle is carried out according to 5.5.1 and 5.5.2.

5.8 Insulation resistance test

5.8.1 Insulation resistance test. the nozzle is not accessed to the power; the wiring end of the coil is in short circuit; and the insulation resistance between the wiring end of the coil and the shell is measured according to the following condition.

a) The nozzle, of which the circuit is packed by synthetic material not exceeding 3.8mm thickness, is applied with 100V DC voltage; maintain for 60s; […]