Gas reducer: device and principle of operation

A gas reducer is a technical device that provides a reduction in the pressure index of a gas mixture or an individual gas in any container or gas pipeline. The same device ensures the constancy of the pressure indicator in the gas pipeline or the capacity (regardless of its variation under the influence of various factors).

Marking and state standard (GOST 13861-89)

• Principle of operation: direct and reverse.

• Purpose and place of application: balloon reducers (marked "B"), ramp reducers ("P"), network gearboxes ("C").

• Type of gas, for reduction of which are used: acetylene reducers (marked "A"), oxygen reducers ("K"), propane-butane reducers ("P"), methane reducers ("M");

• Number of stages (degrees) of gas reduction and method of pressure adjustment:

- single stage reducers with a spring pressure regulator (marked "O");

- two-stage reducers with a spring pressure regulator (marked "D");

- single stage reducers with pneumatic pressure regulator ("З").

In accordance with the rules of GOST, they must differ in color, in which their body is painted. The device of the gas reducer also has a difference in the connecting elements, which are necessary for fixing to the container or to the gas pipeline (using nakidnyh nuts, the thread on which corresponds to the thread of the nozzle located on the valve capacitor or gas pipe ). An exception to this rule are acetylene gas reducers, which are attached to tanks or gas pipelines by means of a clamp and a stop screw.

Basic parameters of gas reducers:

• Pressure at the inlet of the gas reducer: As a rule, the index for compressed (also called "non-fluid") gases is within 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 flow rate when using a reducer (depending on the type of gearbox and its intended purpose) is in the range of several tens of liters of gas for an hour to several hundred cubic meters for the same period of time.

Basic 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 the pressure reading at a constant elevation in the air networks and communications of industrial enterprises. Also this type is used in underwater work and autonomous navigation in order to lower the pressure of the air breathing mixture to an appropriate level.

• Oxygen. The main scope of application and use - autogenous work, gas welding, cutting or soldering at various enterprises of metallurgy and machine building. Also used in medical practice and scuba diving.

• Propane. Use in industry - similar to the previous (plus work on heating). It is also used in construction works (with the use of this type of gearboxes bitumen coatings are laid). In addition, this species is used for household purposes in gas stoves of city apartments and other residential premises. They are subdivided into gears with a constant indicator of the gas pressure established by the manufacturer, as well as samples with the possibility of regulating 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. Reducers for combustible gases, which include methane and hydrogen, are produced with a left-hand thread to avoid the possibility of accidentally attaching the used gearbox used for working with combustible gases to a container filled with oxygen. Containers designed for inert gases, such as argon, helium or nitrogen, have a right-hand thread. A similar thread in tanks with oxygen. Accordingly, for operation 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 are used, including, as a safety valve - back pressure regulators. It is possible to share the pressure relief valves and reducers. In case of such use, the gas reducer should be installed at the entrance to the section of the gas transmission system. It in this case regulates the flow of gas, and the valve installed at the outlet, if necessary, discharges excess pressure of gas or gas mixture. These measures provide overall system stability.

Principle of operation and characteristics of the device

The principle of operation of the gas reducer is determined by its characteristics. Thus, direct-acting gearboxes have a so-called "falling characteristic". This means that the working pressure of the gas decreases as it is used up from the tank. Gas reducers of the reverse action have a so-called "increasing characteristic". In this case, when the pressure of the gas or the gas mixture in the tank decreases, the operating pressure index rises. Also, the gearboxes differ in type of construction, but the principles of operation and the main parts are basically similar.