A gas reducer is a technical device that reduces the pressure of a gas mixture or an individual gas in any containing container or gas pipeline. The same device ensures the constancy of the pressure in the gas pipeline or tank (regardless of its change under the influence of various factors).
Marking and state standard (GOST 13861-89)
• Operating principle: direct and reverse.
• Purpose and place of application: balloon reducers (marked "B"), ramp reducers ("R"), network reducers ("C").
• Type of gas for which reduction is used: acetylene reducers (marked "A"), oxygen reducers ("K"), propanobutane reducers ("P"), methane reducers ("M");
• Number of gas reduction stages (degrees) and pressure adjustment method:
- single-stage gearboxes with spring pressure regulator (marked "O");
- two-stage gearboxes with spring pressure regulator(marked "D");
- single-stage gearboxes with pneumatic pressure regulator ("З").
In accordance with the rules of GOST, they must differ in the color in which their body is painted. The gas reducer device also has a difference in the connecting elements that are necessary for fastening to the tank or to the gas pipeline (using union nuts, the thread on which corresponds to the thread of the fitting located on the valve of the tank or gas pipeline). An exception to this rule are acetylene gas reducers, which are attached to tanks or gas pipelines with a clamp and stop screw.
Main parameters of gas reducers:
• Pressure at the inlet of the gas reducer: as a rule, the indicator for compressed (also referred to as "non-liquefied") gases is up to 250 atmospheres and within 25 atmospheres for dissolved and liquefied gases.
• Pressure at the outlet of the gas reducer: typical devices have an indicator of 1-16 atmospheres, although manufacturers sometimes offer other modifications.
• The gas consumption rate when using a reducer (depending on the type of reducer and its intended purpose) ranges from several tens of liters of gas per hour to several hundred cubic meters over the same period of time.
Main types of gas reducers:
• An air reducer, also called a regulator, which is designed to be used to reduce the pressure of atmospheric air and maintain a constant pressure in air networks andcommunications of industrial enterprises. This type is also used in underwater work and autonomous navigation in order to lower the air pressure indicator of the breathing mixture to the proper level.
• Oxygen. The main field of application and use is autogenous work, gas welding, cutting or soldering at various enterprises of metallurgy and mechanical engineering. Also used in medical practice and scuba diving.
• Propane. Use in industry - similar to the previous one (plus heating work). It is also used in construction work (with the use of this type of gearboxes, bituminous coatings are laid). In addition, this type is used for domestic purposes in gas stoves in city apartments and other residential premises. They are divided into gearboxes with a constant gas pressure indicator set by the manufacturer, as well as samples with the possibility of adjusting this indicator.
• Acetylene. The main scope of application is gas welding of pipelines, as well as their cutting.
The gas reducer is designed for non-flammable or combustible gas mixtures and gases. Regulators for combustible gases, which include methane and hydrogen, are manufactured with left-hand threads to avoid the possibility of accidentally attaching a used reducer used for combustible gases to a container filled with oxygen. Vessels for inert gases such as argon, helium or nitrogen have right hand threads. Similar thread for containers withoxygen. Accordingly, for work with inert gases, it is possible to use oxygen gas reducers.
The gas reducer can also act as a safety valve that relieves excess gas pressure. In English, these concepts are different. Conventional gearboxes are called pressure regulators. Reducers used, including as a safety valve - back pressure regulators. Combination of pressure relief valves and reducers is possible. In the case of such use, the gas reducer should be installed at the inlet to the section of the gas transmission system. In this case, it regulates the flow of gas, and the valve installed at the outlet, if necessary, relieves excess pressure of the gas or gas mixture. These measures ensure the overall stability of the system.
The principle of operation and characteristics of the device
The principle of operation of a gas reducer is determined by its characteristics. So, direct-acting gearboxes have a so-called "falling characteristic". This means that the working pressure of the gas decreases as it is consumed from the tank. Reverse acting gas reducers have a so-called "increasing characteristic". In this case, when the pressure of the gas or gas mixture in the tank decreases, the operating pressure indicator increases. Also, gearboxes differ in type of construction, but the principles of operation and the main parts are basically the same.
