Oxygen pressure reducing valve works and its use

In physical chemistry experiments, oxygen, nitrogen, hydrogen, argon, and other gases are often used. These gases are generally stored in dedicated high pressure gas cylinders. When using the pressure reducing valve to reduce the gas pressure to the required range of the experiment, and then fine-tuning through other control valves to make the gas input to the system. The most commonly used pressure reducing valve is an oxygen pressure reducing valve, or oxygen table for short.

1. The working principle of oxygen relief valve The appearance and working principle of oxygen relief valve.

The high pressure chamber of the oxygen relief valve is connected to the cylinder. The low pressure chamber is the gas outlet and leads to the use system. The high pressure gauge is shown as the pressure of the stored gas in the cylinder. The outlet pressure of the low pressure gauge can be controlled by the adjusting screw.

When using, first open the cylinder main switch, then turn the low pressure gauge pressure adjusting screw clockwise so that it compresses the main spring and drives the diaphragm, the spring block and the ejector lever to open the valve. In this way, the imported high-pressure gas is decompressed by the high-pressure chamber and then enters the low-pressure chamber after being depressurized, and is passed through the outlet to the working system. Turn the adjusting screw to change the opening height of the valve, so as to adjust the throughput of the high pressure gas and reach the desired pressure value.

Pressure relief valves are fitted with safety valves. It is a device that protects the pressure reducing valve and makes it safe to use. 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 mat, trap or due to other reasons, the safety valve will automatically open the vent.

2, the use of oxygen relief valve (1) according to the different requirements, oxygen pressure relief valve has many specifications. Most of the maximum import pressure is that the minimum import pressure is not less than 2.5 times the outlet pressure. There are many export pressure specifications. Generally, the maximum export pressure is.

(2) When installing the pressure reducing valve, make sure that its connection specification is consistent with that of the cylinder and the use system. The pressure reducing valve is connected with the cylinder by a hemispherical surface and the two nuts are fully matched by tightening the nuts. Therefore, the two hemispherical surfaces should be kept clean during use to ensure a good airtight effect. High-pressure gas can be used to blow off dust before installation. If necessary, materials such as Teflon can also be used as gaskets.

(3) Oxygen pressure reducing valve should be strictly prohibited from contacting with grease so as to avoid a fire accident.

(4) When the work is stopped, the residual gas in the pressure reducing valve should be placed on the net, 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 vibration and should not be in contact with corrosive substances.

3, other gas relief valve Some gases, such as nitrogen, air, argon and other permanent gases, can use oxygen relief valve. However, there are some gases, such as ammonia and other corrosive gases, which require special pressure relief valves. Commonly used in the market are nitrogen, air, hydrogen, ammonia, acetylene, propane, steam and other special pressure reducing valve.

The use methods and precautions of these pressure reducing valves are basically the same as those of the oxygen pressure reducing valve. However, it should also be pointed out that dedicated pressure relief valves are generally not used for other gases. In order to prevent misuse, some special pressure relief valves and cylinders use special connections. For example, both hydrogen and propane use left-hand thread, also called reverse thread, and special attention should be paid when installing.