GB/T 26779-2021Fuel cell electric vehicles - Refuelling receptacle (English PDF)

3.1 Receptacle

a component assembly connected to the hydrogenation gun on the vehicle

3.2 Nominal working pressure

in the standard state, the designed rated filling pressure

5.1 General requirements

5.1.1 The interface type and size shall meet the requirements of Annex A.

Designs such as chamfering, protective cover fixing groove, hexagonal shape that are easy to install are allowed. Such design shall not affect the normal engagement of the hydrogenation gun.

5.1.2 In order to solve the freezing problem of hydrogenation gun caused by hydrogen pre-cooling, refer to Annex B for the design of receptacle.

5.1.3 A check valve shall be included in the design of receptacle.

5.2 Performance requirements

5.2.1 Air tightness

Carry out the air tightness test according to the method specified in 6.3. First use a leak detector to check. If no bubbles are generated within 1min, it is conforming. If bubbles occur, continue using the leak detector or other methods to measure.

5.2.2 Vibration resistance

Carry out the vibration resistance test according to the method specified in 6.4.

All connectors shall not be loose. Its air tightness shall meet the requirements of 5.2.1.

5.2.3 Temperature resistance

Carry out the temperature resistance test according to the method specified in 6.5. There shall be no air bubbles.

5.2.5 Oxygen aging resistance

For the seals in contact with hydrogen at the receptacle, carry out the oxygen aging test according to the method specified in 6.7.

5.2.6 Ozone aging resistance

For the seals in contact with air at the receptacle, carry out the ozone aging resistance test according to the method specified in 6.8. There shall be no obvious deformation, deterioration, spots, cracks and so on.

5.2.7 Compatibility

For the non-metal parts in contact with hydrogen at the receptacle, carry out the compatibility test according to the method specified in 6.9. Its volume expansion rate shall not be greater than 25%.

5.2.8 Hydrostatic strength

The pressure-bearing parts of the receptacle shall be subjected to the hydrostatic strength test according to the method specified in 6.10. There shall be no cracks or permanent deformation.

5.2.9 Salt spray corrosion resistance

Test according to the method specified in 6.11. The receptacle shall not show signs of corrosion or peeling off the protective layer. The receptacle shall meet the air tightness requirements specified in 5.2.1.

5.2.11 Compatibility

Only the receptacle with a nominal working pressure of 70MPa needs to be tested for compatibility. Carry out the compatibility test according to the method specified in 6.13. After the test, there shall be no abnormal wear and shall meet the requirements for air tightness in 5.2.1.

6.1 General

Unless otherwise specified, the test shall be carried out under the following conditions.

6.2 Appearance and size inspection

Use visual inspection for the appearance inspection of receptacle. Size measurement can be added if necessary.

6.3 Air tightness test

When the check valve of the receptacle is closed, at the outlet end of receptacle, access with leak detection gas. Respectively test under two pressure states of 0.5MPa and 1.25 times the nominal working pressure.

6.4 Vibration resistance test

Reliably fix the test piece on the vibration test bench. From 5Hz~60Hz, each integer frequency point needs to vibrate 8min, 448min in total. The amplitude is shown as Table 2.

6.5 Temperature resistance test

The check valve of the receptacle is closed. Fill the outlet end of the receptacle with a leak detection gas whose pressure is the nominal working pressure. Put it in an incubator. The temperature rises from room temperature to 85°C±2°C.

Keep the temperature for 8h. Immerse in 85°C water for 1min. Record whether there are bubbles.

6.6 Durability test

The durability test is carried out according to the following steps. The total number of cycles is 15000.

6.7 Oxygen aging resistance test

The seals in contact with hydrogen at the receptacle shall be placed in oxygen at a temperature of 70°C±2°C and a pressure of 2MPa for 96h. Observe the changing state.

6.8 Ozone aging resistance test

The seals in contact with air at the receptacle shall be placed in the air at a temperature of 40°C±2°C and an ozone volume fraction of 5 x 10^-7 for 120h. Observe the changing state.

6.9 Compatibility test

After the non-metal parts in contact with hydrogen at the receptacle shall be immersed in hydrogen at the nominal working pressure and room temperature for 168h, from the decompression, within 5min, the volume change rate and mass change rate shall be measured according to 7.2 and 7.3 of GB/T 1690-2010. The number of test sample is one.

6.10 Hydrostatic pressure strength test

Seal the outlet end of the receptacle. Access with hydrostatic pressure of 3 times the nominal working pressure. The duration shall not be less than 1min.

6.11 Salt spray corrosion resistance test

The temperature in the salt spray box shall be kept between 33°C~36°C. The receptacle is in horizontal support and exposed to the salt spray that is composed of 5% sodium chloride and 95% distilled water in accordance with GB/T 10125.

6.12 Temperature cycle resistance test

After pressurizing to nominal working pressure, put the receptacle in a thermostat. The temperature shall rise from 15°C to 85°C within 0.5h. Keep it at this temperature for 2h. Then drop from 85°C to -40°C within 1h. Keep it at this temperature for 2h.

6.13 Compatibility test

The compatibility test shall be carried out in accordance with the following steps.