Appearance, working principle, and usage of the oxygen pressure regulator

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In physical chemistry experiments, gases such as oxygen, nitrogen, hydrogen, and argon are often used. These gases are generally stored in specialized high-pressure gas cylinders. During use, the gas pressure is reduced to the range required for the experiment using a pressure reducing valve, and then fine-tuned through other control valves before the gas is fed into the system. The most commonly used pressure regulator is the oxygen pressure regulator, also known as an oxygen gauge. 　　Working principle of oxygen pressure regulator. The appearance and working principle of the oxygen pressure regulator. 　　The high-pressure chamber of the oxygen pressure regulator is connected to the gas cylinder, while the low-pressure chamber serves as the gas outlet and leads to the application system. The reading on the pressure gauge indicates the pressure of the gas stored in the cylinder. The outlet pressure of the low-pressure gauge can be controlled by the adjustment screw. 　　When in use, first turn on the main valve of the gas cylinder, then rotate the pressure adjustment screw of the low-pressure gauge clockwise, which compresses the main spring and drives the diaphragm, spring washer, and push rod to open the valve. In this way, the imported high-pressure gas enters the low-pressure chamber after being throttled and depressurized in the high-pressure chamber, and then reaches the working system via the outlet. Rotate the adjustment screw to change the opening height of the valve, thereby regulating the amount of high-pressure gas that passes through and achieving the desired pressure level. 　　Pressure relief valves are all equipped with safety valves. It is a device that protects the pressure reducing valve and ensures its safe use, as well as a signaling device in case of a malfunction in the pressure reducing valve. If the outlet pressure rises on its own and exceeds a certain allowable value due to damage to the valve gasket or the valve itself, or for other reasons, the safety valve will open automatically to release air. 　　How to use an oxygen pressure regulator (1) Depending on the application requirements, there are many different specifications for oxygen pressure regulators. The maximum inlet pressure is usually such that the minimum inlet pressure is not less than 2.5 times the outlet pressure. There are various specifications for outlet pressure; generally, the maximum outlet pressure is. 　　(2) When installing a pressure relief valve, it is necessary to ensure that its connection specifications match those of the cylinder and the connectors of the system it is to be used with. The pressure relief valve and the gas cylinder are connected via a hemispherical interface, with the nuts being tightened to ensure a perfect fit between them. Therefore, the surfaces of the two hemispheres should be kept smooth during use to ensure a good airtight seal. Before installation, dust can be blown away using high-pressure gas. If necessary, materials such as polytetrafluoroethylene can also be used as washers. 　　(3) Oxygen pressure regulators must not come into contact with grease to prevent fire accidents. 　　(4) When stopping operation, the remaining air in the pressure relief valve should be released completely, and then the adjustment screw should be loosened to prevent the elastic element from being compressed and deformed over time. 　　(5) The pressure relief valve should be protected from impact and vibration, and must not come into contact with corrosive substances. 　　Other gas pressure regulators: For some gases, such as permanent gases like nitrogen, air, and argon, oxygen pressure regulators can be used. However, there are also some gases, such as corrosive gases like ammonia, that require specialized pressure relief valves. Commonly available on the market are specialized pressure relief valves for nitrogen, air, hydrogen, ammonia, acetylene, propane, water vapor, and others. 　　The usage methods and precautions for these pressure relief valves are basically the same as those for oxygen pressure relief valves. However, it should also be noted that dedicated pressure relief valves are generally not used for other gases. To prevent misuse, some specialized pressure relief valves use special connectors with gas cylinders. For example, both hydrogen and propane use left-hand threads, also known as reverse threads, and special attention must be paid when installing them.