GB/T 42177-2022Technical requirements and test methods for gaseous hydrogen valves used in hydrogen fuelling stations (English PDF)

3.1 nominal size

An alphanumeric dimensional designation for valves, consisting of the letters DN followed by a dimensionless integer number.

NOTE: This dimensionless number is directly related to characteristic dimensions such as the bore diameter or outer diameter (expressed in millimeters) of the end fitting. Unless otherwise specified in the relevant standard, the dimensionless number following DN does not represent a measured value and shall not be used in calculations.

[Source: GB/T 1047-2019, 2.1, modified]

3.2 check valve

A valve that the opening and closing parts (valve disc) automatically prevent the reverse flow of the medium with the help of the force of the medium.

3.3 excess flow valve

4.1.2 Valves made of the same material under similar design conditions may not be re-

tested according to the items specified in this document.

4.1.3 In addition to the test items specified in this document, other reliable test methods

can be used to test the service performance of the valve in a high-pressure hydrogen environment.

4.1.4 The performance of pneumatic control valves shall comply with the requirements

specified in GB/T 4213. Electrically controlled valves shall adopt explosion-proof electric mechanisms. The selection of explosion-proof grade shall comply with the requirements specified in GB 50156 and GB 50516.

4.1.5 The valve shall be reliably sealed and clean to prevent internal and external

impurities from contaminating the hydrogen.

4.2 Materials

4.2.1 Valve materials shall consider corrosion resistance, wear resistance, aging

resistance, electrical conductivity, impact strength, heat resistance, low temperature impact resistance, ultraviolet radiation resistance and hydrogen embrittlement resistance.

4.2.2 Metal materials shall have good hydrogen compatibility. The test methods shall

be implemented in accordance with the requirements specified in GB/T 34542.2 and

GB/T 34542.3.

4.2.3 Non-metallic materials shall have good hydrogen compatibility. Its fatigue

performance, durability limit and creep strength shall meet the requirements of the design documents within the design life of the valve.

4.2.4 The service temperature range of non-metallic seal materials shall meet the

requirements of the valve operating temperature. Its tensile strength and elongation after break shall be measured according to the requirements specified in GB/T 528 and meet the requirements of the design documents.

4.3 Working pressure level

Working pressure level (HSL) is represented by "H+ value", in MPa. Its relationship with nominal working pressure (NWP), maximum working pressure (1.25 NWP), and maximum allowable working pressure (1.375 NWP) is shown in Table 1 .

5.2.3 Test medium

The test medium shall meet the following requirements:

a) The medium for the extreme temperature hydrogen cycle test, leakage test, overpressure hydrogen cycle test, bending test, non-metal seal test, pre-cooled hydrogen exposure test, action cycle test, pressure pulse test and opening and closing cycle test is hydrogen;

b) The medium of hydrostatic test is water;

c) The medium for other tests can be helium, nitrogen or dry clean air.

5.3 Extreme temperature hydrogen cycle test

5.3.1 Test method

Block the valve outlet. Connect the valve inlet to the hydrogen source. The lower limit of circulating pressure shall not exceed 0.05 times the maximum allowable working pressure of the valve. The upper limit of circulating pressure shall be within the range of (1~1.03) times the maximum allowable working pressure of the valve. The frequency shall not exceed 10 times/min. Valve seals can be replaced after 16,000 pressure cycles.

The test shall be carried out according to the following steps:

a) Normal temperature: At normal temperature, the valve is continuously tested for 100,000 cycles;

b) High temperature: The valve is continuously tested for 1,000 cycles at a test temperature of no less than 85°C;

c) Low temperature: The valve is continuously tested for 1,000 cycles at a test temperature not higher than -40°C.

5.3.2 Qualification indicators

The valve shall not leak or rupture within 102,000 pressure cycle tests.

5.4 Leakage test

5.4.1 Test methods

5.4.1.1 Test preparation

Before testing, purge the valve with nitrogen. And seal it at 0.3 times the maximum allowable working pressure of the valve. For high and low temperature tests, the valve shall be left to stand at the specified temperature for at least 1 h before the test.

shall comply with the requirements specified in 5.4.2.

5.10 Non-metal seal test

5.10.1 Test method

Block the valve outlet. Connect the valve air inlet to the air source. At normal temperature, fill with hydrogen to the maximum allowable working pressure of the valve. After maintaining the pressure for 70 h, the test pressure was quickly reduced to atmospheric pressure. Afterwards, conduct a leakage test on the valve according to the test method specified in 5.4.1.

5.10.2 Qualification indicators

Use special leak detection fluid to detect leaks. There shall be no bubbles generated within the specified test time.

5.11 Precooled hydrogen exposure test

5.11.1 Test method

The test steps are as follows:

a) Fill the valve with pre-cooled hydrogen gas at a temperature not higher than -40°C at a flow rate of not less than 30 g/s at normal temperature for at least 3 min. After that, stop inflating for 2 min. Repeat the above operation 10 times;

b) Fill the valve with pre-cooled hydrogen gas at a temperature not higher than -40°C at a flow rate of not less than 30 g/s at normal temperature for at least 3 min.

After that, stop inflating for 15 minutes. Repeat the above operation 10 times;

c) The valve shall be tested for leakage according to the test method specified in 5.4.1.

NOTE: Only suitable for valves through which pre-cooled hydrogen flows.

5.11.2 Qualification indicators

Use special leak detection fluid for leak detection, and no bubbles shall be generated within the specified test time.

a) Connect the air inlet and outlet of the overflow valve to the pipeline. The air inlet pipeline is connected to the air source. The length of the connecting pipeline between the air inlet and the air outlet is at least 1 m;

b) Before the test, the pressure at the air outlet and air inlet of the overflow valve shall be atmospheric pressure;

c) Quickly charge hydrogen to the maximum allowable working pressure of the valve. Then release the pressure to atmospheric pressure. The number of cycles is 100 times;

d) Fill the hydrogen gas in the opposite flow direction to c) to the maximum allowable working pressure of the valve. Then release the pressure to atmospheric pressure. The number of cycles is 100 times;

e) Carry out action cycle test according to the provisions of 7.10.

7.11.2 Qualification indicators Use special leak detection fluid for leak detection, and no bubbles shall be generated within the specified test time.

8 Control valves

8.1 Extreme temperature hydrogen cycle test Carry out extreme temperature hydrogen cycle test in accordance with the provisions of 5.3.

8.2 External leakage test Carry out external leakage test according to the test method specified in 5.4.1.2. The test results shall comply with the requirements specified in 5.4.2.

8.3 Overpressure hydrogen cycle test Carry out overpressure hydrogen cycle test in accordance with the provisions of 5.5.

8.4 Hydrostatic test Carry out hydrostatic test in accordance with the provisions of 5.6.

Where, t - the resting time, in hours (h);

dmax - the maximum diameter of the break away coupling, in millimeters (mm).

9.2.2 Qualification indicators Use special leak detection fluid to detect leaks, and no bubbles shall be generated within the specified test time.

9.3 Overpressure hydrogen cycle test Carry out overpressure hydrogen cycle test in accordance with the provisions of 5.5.

9.4 Hydrostatic test Carry out hydrostatic test in accordance with the provisions of 5.6.

9.5 Hydraulic strength test

9.5.1 Test method Carry out the hydraulic strength test of the breakaway valve in accordance with the following requirements:

a) For the assembled break away coupling: After purging the break away coupling with nitrogen, seal the outlet of the break away coupling. Apply a hydraulic pressure of 2.4 times the maximum allowable working pressure of the valve to its inlet at normal temperature, and maintain the pressure for 3 min;

b) For the input side and output side of the break away coupling: The relief hole on the output side of the break away coupling shall be blocked. After purging the input and output sides of the break away coupling with nitrogen, apply a hydraulic pressure of 2.4 times the maximum allowable working pressure of the valve to the input and output sides at normal temperature, and maintain the pressure for 5 min.

9.5.2 Qualification indicators The break away coupling shall not break. When performing a hydraulic strength test on the assembled break away coupling, if the break away coupling separates during the pressurization process, and the pressure during separation is not less than 1.5 times the maximum allowable working pressure of the valve, a clamp shall be used to secure the input and output sides of the break away coupling. Repeat the hydraulic strength test.

In addition, the assembled break away coupling shall not leak when the test pressure is gas to not less than 0.8 times the maximum allowable working pressure of the valve.

Allow the manual valve to reach maximum flow and then close the valve. Afterwards, conduct a leakage test on the manual valve according to the test method specified in 5.4.1.

10.9.2 Qualification indicators The manual valve shall be able to be completely closed and shall meet the requirements specified in 5.4.2.

10.10 Open and close cycle test

10.10.1 Test method At the test temperatures of not higher than -40 degrees C and not lower than 85 degrees C, follow the following steps:

a) Connect the air inlet of the manual valve to the air source, and the air outlet to a ventilated place;

b) Close the manual valve;

c) Fill the hydrogen gas to the maximum allowable working pressure of the valve.

Afterwards, open the valve to relieve pressure to atmospheric pressure;

d) Repeat operations b) and c) 150 times;

e) Carry out leakage test according to the test method specified in 5.4.1.

10.10.2 Qualification indicators Manual valves shall be free from leakage and rupture.

10.11 Torque cycle test

10.11.1 Test method Secure the manual valve with a clamp. Use a torque wrench or other device capable of setting torque to apply 1.5 times the design maximum torque to the closed manual valve to fully open it. The number of cycles is 20 times. Afterwards, perform a leakage test on the manual valve according to the test method specified in 5.4.1.

NOTE: This test does not apply to manual ball valves.

10.11.2 Qualification indicators The manual valve shall not be deformed or broken, and shall meet the requirements