Oxygen reducing valve working principles and using method
In physical chemistry experiments, often use oxygen, nitrogen, hydrogen, argon and other gases. These gases are generally stored in a dedicated high-pressure gas cylinders. When using through the reducing valve to make gas pressure down to the test required range, and then through other control valves for fine-tuning, makes gas entered the system. The most commonly used reducing valve is oxygen valve, referred to as oxygen table.
1. oxygen reducing valve working principles
oxygen reducing valve appearance and working principles
The oxygen reducing valve high-pressure chamber connects with steel cylinder, low-pressure chamber is gas outlet and access to using system. High-pressure table value is the steel cylinder stored gas pressure. Low-pressure table outlet pressure can be controled by adjustable screw.
When using, you should first open steel cylinder master switch, and then the clockwise rotating low pressure table regulative screw, makes it compress main spring and transmits diaphragm, spring pads, and push-rod, opens the trap door. The inlet high-pressure gas from the high-pressure chamber enters in low-pressure chamber after the throttle and decompression, and through the outlet to leading to the working system. Rotating adjustable screw to change the valve opening height, thus regulating the passing amount of high-pressure gases and to achieve the required pressure value.
Reducing valves are equipped with safety valve. It is the device that protects reducing valve and make it safe use, is also a signal device when reducing valve occurs failure. If living doormat, valve damage, or other reasons, resulting in outlet pressure increased, and exceeds a certain permitted value, the safety valve will automatically open for the exhaust.
2. The use of oxygen valve
(1) according to the different applicable requirements, oxygen valve has many specifications. The minimum inlet pressure is not less than 2.5 times of the outlet pressure.
(2) When installing pressure reducing valve, you should confirm whether its connecting dimensions are the same with the cylinder and the using system connector. Reducing valve and steel cylinder adopt hemispherical connections, rely on tighten nut to make the two fit together well. Therefore, when using, you should maintain the two hemispheres surface smooth in order to ensure good gas-sealing effect. Before installation you can use high-pressure gas to blow dust. When necessary, you can also use PTFE and other materials as a gasket.
(3) The oxygen reducing valve should be forbidden contacting with grease, to avoid fire accidents.
(4) When stop working, you should empty the reducing valve residual gas, and then loosen the adjustable screw so as to avoid long-term compressive deformation of elastic components.
(5) The reducing valve should be avoided to shock vibration, can not be in contact with corrosive substances.
3. Other Gas reducing valves
Some gases, such as nitrogen, air, argon gas and other permanent gases, oxygen reducing valve can be used. But there are a number of gases such as ammonia and other corrosive gases, you need special reducing valve. Commonly are nitrogen, air, hydrogen, ammonia, acetylene, propane, water vapor and other special reducing valves.
The use methods and precautions of these valves are basically the same with the oxygen reducing valve. However, it should be noted: special reducing valve is generally not used for other gases. In order to prevent misuse, and between some special valves and steel cylinder uses special connector. For example, hydrogen and propane are using left root thread, also known as reverse-threaded, you should pay more attention when installation.
