Hefei Sinopower Technologies Co., Ltd
Working principle and application of hydrogen valve
The high-pressure chamber of the hydrogen valve is connected with the steel cylinder, and the low-pressure chamber is the gas outlet and leads to the use system. The indication of the high pressure gauge is the pressure of the gas stored in the cylinder. The outlet pressure of low pressure gauge can be controlled by adjusting screw.
When in use, first open the main switch of the cylinder, and then turn the pressure adjusting screw of the low pressure gauge clockwise to compress the main spring and drive the diaphragm, spring block and ejector rod to open the valve. In this way, the high-pressure gas at the inlet enters the low-pressure chamber after throttling and decompression from the high-pressure chamber, and then leads to the working system through the outlet. Turn the adjusting screw to change the opening height of the valve, so as to adjust the throughput of high-pressure gas and reach the required pressure value.
All pressure reducing valves are equipped with safety valves. It is not only a device to protect the pressure reducing valve and make it safe to use, but also a signal device for the failure of the pressure reducing valve. If the outlet pressure rises automatically and exceeds a certain allowable value due to valve pad, valve damage or other reasons, the safety valve will automatically open for exhaust.
Due to the particularity of hydrogen medium (small molecule, easy penetration, hydrogen embrittlement, explosive, etc.), the quality of valve body and valve cover is very high.
1. Forging (integral forging) is preferred for valve body and cover material. For example, casting can be selected for large diameter valve, but RT secondary sheet standard must be made;
2. The design and manufacture of valves should not have sharp chamfers, all chamfers should be smooth and excessive, and the machining accuracy and surface of parts should be very high;
3. The valve should be cleaned strictly;
4. In the pressure test, the strength test needs to do the gas strength test, not only the strength test with water as the medium;
5. For valves with high content of P, s and other materials, it is necessary to carry out metallographic test;
6. For valves with hydrogen medium, hydrogen test can also be conducted according to shell77 / 308 specification.
7. We must pay attention to fire prevention, anti flying and anti-static