The working principle of oxygen pressure reducing valve and how to use it

In physical and chemical experiments, gases such as oxygen, nitrogen, hydrogen, and argon are often used. These gases are generally stored in special high-pressure gas cylinders. When in use, the gas pressure is reduced to the range required by the experiment through the pressure reducing valve, and then fine-tuned by other control valves, so that the gas is input into the use system. The most commonly used pressure reducing valve is the oxygen pressure reducing valve, or oxygen meter for short. 1. Oxygen reduction In physical and chemical experiments, gases such as oxygen, nitrogen, hydrogen, and argon are often used. These gases are generally stored in special high-pressure gas cylinders. When in use, the gas pressure is reduced to the range required by the experiment through the pressure reducing valve, and then fine-tuned by other control valves, so that the gas is input into the use system. The most commonly used pressure reducing valve is the oxygen pressure reducing valve, or oxygen meter for short. 1. The working principle of the oxygen pressure reducing valve The appearance and working principle of the oxygen pressure reducing valve. The high pressure chamber of the oxygen pressure reducing 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 meter is the pressure of the gas stored in the cylinder. The outlet pressure of the low pressure gauge can be controlled by the adjusting screw. When in use, first turn on the main switch of the cylinder, and then turn the low pressure gauge pressure adjusting screw clockwise to compress the main spring and drive the membrane, spring pad and ejector rod to open the valve. In this way, the imported high-pressure gas enters the low-pressure chamber from the high-pressure chamber through throttling and decompression, and then leads to the working system through the outlet. Turn the adjusting screw to change the opening height of the valve, thereby adjusting the throughput of high-pressure gas and reaching the required pressure value. The pressure reducing valve is equipped with a safety valve. It is a device to protect the pressure reducing valve and make it safe to use, and it is also a signal device for the failure of the pressure reducing valve. If the outlet pressure rises by itself and exceeds a certain allowable value due to damage to the valve pad, valve or other reasons, the safety valve will automatically open to exhaust. 2. How to use oxygen pressure reducing valve (1) According to different requirements, there are many specifications of oxygen pressure reducing valve. The maximum inlet pressure is mostly, and the minimum inlet pressure is not less than 2.5 times the outlet pressure. There are many outlet pressure specifications, generally, the highest outlet pressure is. (2) When installing the pressure reducing valve, make sure that its connection specifications are consistent with the joints of the steel cylinder and the use system. The pressure reducing valve and the steel cylinder are connected by a hemispherical surface, and the two are completely matched by tightening the nut. Therefore, the two hemispherical surfaces should be kept smooth during use to ensure a good air-tight effect. Before installation, high-pressure gas can be used to blow off the dust. If necessary, materials such as polytetrafluoroethylene can also be used as gaskets. (3) The oxygen pressure reducing valve should be strictly prohibited from touching grease to avoid fire accidents. (4) When the work is stopped, the remaining air in the pressure reducing valve should be drained, and then the adjusting screw should be loosened to prevent the elastic element from being deformed under pressure for a long time. (5) The pressure reducing valve should avoid impact and vibration, and should not come into contact with corrosive substances. 3. Other gas pressure reducing valves Some gases, such as nitrogen, air, argon and other permanent gases, can use oxygen pressure reducing valves. But there are some gases, such as ammonia and other corrosive gases, which require special pressure reducing valves. Commonly available in the market are special pressure reducing valves for nitrogen, air, hydrogen, ammonia, acetylene, propane, and steam. The usage and precautions of these pressure reducing valves are basically the same as those of oxygen pressure reducing valves. However, it should also be pointed out that special pressure reducing valves are generally not used for other gases. In order to prevent misuse, special connection ports are used between some special pressure reducing valves and steel cylinders. For example, both hydrogen and propane use left-hand thread, also called reverse thread, so special attention should be paid when installing.