The reduction device for gas cylinders is designed to stabilize the gas pressure and bring it to operating parameters at the outlet of the cylinder. In other words, if there is a high or unstable gas pressure at the inlet, then at the outlet this parameter becomes low and constant. In the article, we consider what a gas reducer for a cylinder with a regulator is, its application and principle of operation.
Instrument Features
Thanks to the reducer, the working pressure remains constant even when the gas pressure in the cylinder changes.
Devices differ according to the principle of action (direct or reverse) and are produced for the reduction of various gases: hydrogen, propane-butane, oxygen, acetylene. Structurally, they have two or one stage and the ability to set the working pressure with a pneumatic or spring device.
Depending on the type of gas being regulated, reducers for a gas cylinder with a pressure regulator are painted in different colors.
The device is connected using nuts corresponding to the thread of the threaded fitting on the valve. An exception is acetylene reduction gears that are attached to the tank using clamps with stop screws.
It is important that the reducers for flammable gas cylinders are left-handed, which eliminates their attachment to oxygen. Inert gas or oxygen cylinders are right-handed.
The reducer is selected depending on the gas flow rate and the parameters of the inlet and outlet pressure.
Device use
The use of reducers is due to their property of lowering and stabilizing gas pressure and is used both in household and agriculture, as well as in medicine and industry.
This is required in such cases:
- a reducer with a regulator for a domestic gas cylinder - used in domestic autonomous gas supply systems and in cylinders that supply gas to cooking surfaces;
- in automobile gas equipment - before the supply of liquefied gas to the engine;
- on main pipelines - to divert natural gas to settlements where the pressure is much lower;
- on submission to welding, plumbing and heating equipment;
- to provide medical care;
- during construction work - propane gas reducers for cylinders with a regulator are used for bitumen and roofing materials.
Gas pressure regulators
Gas distribution can also be done using pressure regulators. They make it possible to maintain a constant pressure level at the sampling point, independent of the volume of gas consumed. These devices are used to complete modern composite cylinders. An example of such a device is the Gok regulator with a gas reducer for a cylinder.
When applying the initial high pressure, the regulator throttle automatically sets the opening value to the desired value, which leads to a change in hydraulic pressure and a decrease in the working pressure of the gas stream.
The support of the obtained value with the help of regulators is realized in two ways - before or after, by acting on the moving component through the membrane head.
Depending on the type of force applied to the movable system, the regulators are divided into lever and spring.
The principle of operation of a direct gear
Structurally, all gas reducers for a cylinder with a regulator are arranged similarly, differing only in the dimensions of the device and holes, the area of the membranes and the size of the springs.
The design of a conventional direct pressure reducing apparatus for gas is a two-chamber (high and low pressure) cavity with a separator in the form of a rubber membrane; fittings are located at the inlet and outlet of the cavity. In modern models, there is also a third input for connecting a manometer.
The feed gas moves through the hose and, passing through the inlet fitting, enters the first chamber. The fuel pressure tries to snap off the valve, which on the other hand is supported by a locking spring - it returns it to its seat. Moving in this direction, the valve does not allow gas under high pressure to flow freely from the cylinder.
The membrane is the second acting force, which has the opposite effect, trying to lift the valve from its seat and open the passage of high-pressure gas. That is, a situation is created in which, on the one hand, the opening pressure spring presses on the membrane, and on the other hand, the gas entering the low-pressure chamber.
When the gas escapes, the working pressure in the chamber decreases, and the spring straightens, pushing the valve out and allowing a new portion of gas to enter the device. In this case, the pressure begins to increase, pressing on the spring and returning the valve to its place, thereby blocking the gas flow. The process is then repeated.
It should be noted that adjustable gearboxes for direct gas cylinders are not widely used due to their complex design, in contrast to reverse gears, which are considered even safer.
Reverse gear
Gearboxes of this type have the opposite principle of operation as described above.
Liquefied gas is supplied to the high-pressure chamber and, having accumulated, does not allow the valve to open. After turning the handle, which provides gas to the consumer, the turning screw starts to put pressure on the compression spring. In turn, it contracts and presses on the membrane, which opens the valve, increasing the gap. Through this gap, gas enters the low pressure chamber.
This leads to an increase in pressure not only in the chamber, but also in the cylinder and in the hose. Under this action, with the help of a spring, the membrane straightens, the pressure increases and the transfer disk, lowering, weakens the return spring. That, in turn, seeks to return the valve to its place and close the gap, limiting the flow of gas and reducing the pressure. From this moment, the process begins again.
In general, the principle of operation of a gas reducer for a cylinder with a regulator resembles a float chamber.
Gear selection
When choosing devices of this type, several factors should be considered.
These include:
- An important parameter of the gearbox operation is the maximum gas flow rate, determined by the size of the inlet valve opening. In other words, this is an indicator of how much gas the gas will let through with the valve fully open at a given inlet pressure.
- When choosing a device, you need to pay attention to the presence of a seat under the manometer - with it it is much easier to regulate the compression of the spring to obtain the desired outlet pressure.
- When choosing a gas cylinder, it is important to remember that now the old ones have been replaced by new composite cylinders, safe and less heavy.
- When choosing, you need to pay attention to whether there is a nut for manual adjustment, the life of the membrane, the tightness of the structure, the method of attaching the hose to the fitting (thread or clamp).
- When buying, take into account the type of gas that will be refilled in the cylinder, flow rate and outlet pressure.
The best reviews and widespread use were received in Italy produced gas reducer for the cylinder with regulator M714.
Overview of gas gear models
It is worth noting that this device is not universal - each model is designed to work with a specific gas, so when buying, you must definitely study all the characteristics of the product.
The main comparative overviews for commonly used gearboxes can be seen in the table below.
Inspection and service
In order for the gearbox to work correctly for a long time, it is necessary to follow simple rules.
They are as follows:
- At least once a week, it is required to record the pressure gauge for monitoring, since the elasticity of the springs may decrease over time, and then there will be a constant change in pressure up or down.
- At least once every three months, using a soapy solution, check the tightness of the valves, gaskets and pressure gauge at the points of connection with the device body.
- With the same frequency as in the previous paragraph, blow off the safety valve to prevent sticking. To do this, the gearbox is connected to the supply of compressed air, close the outlet and increase the gas pressure until the protection is activated.
- It is forbidden to carry out service or repair work on a pressurized device in order to avoid depressurization, release or ignition of gas.
- At least twice a year, the valve of the gearbox must be cleaned of clogging.
- Before switching on, inspect the device and pressure gauge for damage.
Precautions and possible malfunctions
To fix problems with the device, you need to invite a specialist, but some of the problems can be solved independently.
A damaged diaphragm or a pressurized housing can cause gas leakage and pressure deviation from the set values. In this case, replace the membrane and liners with sealant. To restore pressure, check the location and suitability of the spring - it can move or be replaced.
In pneumatic gearboxes, repair is difficult to make, therefore, in the event of a breakdown, they are completely replaced. The loss of tightness in the connection points is eliminated by tightening the washers. When rubber gaskets are worn, they are replaced with new ones. After the repair, the gearbox is checked for leaks.
Experts advise to make repairs only in those cases when it is not possible to quickly replace the device itself. In other situations, it is better to buy a new device based on the low price of this equipment.