Gasket for a gas cylinder: what is it for, typical dimensions, instructions for replacement

If you use gas cylinders at home, then you probably know that safety should come first.Agree, nothing adds confidence more than peace of mind for yourself, your loved ones and property. In this sense, everything is decided by the gasket on the gas cylinder - a very cheap and simple remedy. The safety of using the equipment directly depends on its quality and size. It would be nice to protect yourself from explosion, destruction or possible fire, wouldn't it?

We will tell you about the requirements for gaskets and the rules for their use. You will find out what sizes, types they come in, and what features they have depending on the materials used. Together with this information, it will be easier for you to make a choice whether to buy a new or replace the old seal.

Gaskets are used on many connections. In the gas industry, seals are used on cylinders, hoses, and pipelines. This is done for the sake of safety and to minimize fuel losses. Read the article and find out more about it.

What are cylinder gaskets for?

They are used as sealing parts at the points of connection of the valve (faucet) to the neck of the gas cylinder and to the reducer. In the first case, the seal is mounted on the tank body and in a horizontal position, in the second - between the valve fitting and the gearbox, vertically. There are also gaskets inside the valve: under the flywheel, in the unit body and in its valve.

The seal eliminates or prevents gas leakage. Rubber gaskets increase tightness, improve mechanical characteristics, and keep connection parts in working condition.You cannot do without oil seals in rooms with small or no windows, rooms with stagnant air, and unventilated areas.

Consequences of a gas cylinder explosion: what can happen as a result of a small leak, violation of storage conditions and incorrectly selected premises

Gaskets improve performance gearboxes. The latter are connected when gas is supplied through a hose to reduce or stabilize pressure. In the process, the usual indicator of 16-50 or the maximum of 150-250 atmospheres reaches values ​​from 1 to 16, and the probability of an explosion increases compared to the state when the cylinder is not used. The seal reduces the risk.

After prolonged use of the cylinders, the seals become deformed. They are changed about as often as cylinder taps.

In addition to sealing gaskets, transportation gaskets are used with gas cylinders: the rings are placed on the wide part of the body, in 2 places.

Materials for seal

Paronite, rubber and fluoroplastic are used in production.

Due to its adhesiveness, paronite tightly fills cracks and gaps. The connections are specially protected with graphite so that the material does not stick to them. Biological and climatic factors have little effect on paronite, and a sealant with mineral additives will survive contact with aggressive hydrocarbons. As the ideal size of the washer is exceeded, its effect becomes minimal.

Rubber is used because of its elasticity and ability to restore shape. Other properties include amorphousness and elasticity. The latter indicator increases with the ambient temperature. Hardness is controlled by the degree of vulcanization, plasticizers and fillers.

Seals are made of nitrile butadiene rubber with an upper temperature limit of +120...+130 °C and fluorine rubber, which can withstand up to +150...+200 °C.

Paronite gaskets are used not only on gas cylinders, but also on stoves, meters, columns, hoses and connections

Fluoroplastic exhibits resistance to chemical and corrosive processes. The material was also found to have weather resistance, heat and frost resistance. Due to low gas permeability, fluoroplastic began to be used in private homes and household gas distribution systems. After ignition, it quickly dies out, and the friction coefficient is in the range of 0.4–0.05 at a load of 1–20 kgf/cm².

In practice, silicone profiles are also used, but general safety standards prohibit installing the material on gas and fire equipment. Silicone seals reliably, exhibits high temperature resistance, but is highly flammable.

Range of sizes and gasket models

Gasket efficiency for gas cylinder depends on its size and dimensions of the unit. In the case of transport rings, the inner diameter should be slightly smaller than the diameter of the cylinder. For sealing rings inside connections, exact matching dimensions are important.

Washers for external structures are selected according to the outer and inner diameter. All types of sealing gaskets are subject to heavy loads, so their compatibility with equipment depends on pressure indicators.

Rings for necks and reducers have a flat configuration. Their sizes are regulated GOST 15180-86. The document described the parameters of flat elastic gaskets made of fluoroplastic, paronite, rubber and materials based on them.Standardized products seal flanges and connecting parts, which are elements of the gas cylinder valve and various fittings.

Gas cylinders can be high and low, wide and narrow, with parts of different proportions - the gaskets for them are noticeably different in configuration, even if they have the same purpose

The size range of gaskets corresponds to the nominal bore (DN, Dу) in millimeters and the nominal pressure (PN, Pnom, Pu) in MPa. Both indicators are also called nominal.

The first displays the internal diameter of the structural element through which the gas moves. The nominal pressure acts as a conditional indicator, which was established based on strength calculations at a temperature of +20 °C.

Dimensions of sealing gaskets according to GOST:

Shipping spacers are used during transportation and storage. The rings protect the container from damage, damage to the paint layer, and impacts against other containers. Products for gas cylinders are produced in accordance with TU 2500-376-00152106-94. The peculiarity of these rings is their circular cross-section.

Some products:

1. OH-1101: 25 ±1.3, 215 ±3.
2. OH-1102: 25 ±1, 210 ±3.2.
3. OH-2202: 15.6 ±1, 285 ±3.
4. OH-3303: 25 ±1.6, 140 ±2.5.

The first indicator displays the cross-sectional diameter of the ring in millimeters, the subsequent indicator displays the internal diameter (mm). These products are used under conditions of normal external pressure and temperature range -40…+40 °C.

Requirements for sealing products

The gasket must correspond to the drawing. Displacement of the shape is allowed within the limits of the size indicated in special tables.

Reducer on a gas cylinder: the gasket at the junction of the converter and the valve has to be changed more often - usually disposable seals are used, but some models of reducers do not need a gasket at this connection at all

Do not place washers with cracks, bubbles or porosity on the working surfaces (P). In the case of non-working ones (NR), only gaskets with cracks are not used, but exceptions are made for other parameters.

On surfaces of both types, gaskets with some defects can be installed if they do not exceed the permissible values:

1. Imprint on the surface of the product. With depth, length and width allowed for the gasket size.
2. A chip up to 0.3-1.5 mm long, depending on the thickness of the seal.
3. Pressing out up to 0.3-1.5 mm high. The value also depends on the thickness of the washer.
4. Depressions, elevations and inclusions. Up to 0.3-5 mm.
5. Under-formation. Up to 0.3-5 mm, based on the thickness of the gasket.
6. Retracted edge. With a size of up to 0.3-1 mm.

Before installation, the gaskets are cleaned of dirt and dust and the target surface is prepared in the same way. The rings are fastened without shock loads, with short stretching.

The condition of the sealing gasket can be determined by the unit in which it is installed. After changing the unit or removing the product itself, it is subject to further use if the appearance remains unchanged and the dimensions are maintained.

The criteria also apply to seals and transport rings for propane gas cylinders of 2, 5, 10, 12, 15, 20, 27, 40, 50 liters and more. Products for methane cylinders of 47, 50, 67, 80, 85, 96, 100, 123, 132, 160 and 185 liters fall under the standards.

Gasket replacement procedure

Changing the O-ring on the body neck often coincides with replacing the valve. The gasket is updated if a problem with it or the faucet is identified.

Before connecting a gas cylinder to any gas-using appliance, worn parts on the container should be replaced: their appearance will be the best guide

They resort to replacing the valve if:

• it is not possible to move the flywheel, it has become more difficult to turn it;
• there is deformation of the valve or its parts;
• there is a smell of gas in the room;
• The scheduled technical inspection did not take place.

Gaskets are changed with a precise algorithm of actions. First, the cylinder itself is taken as far as possible from buildings. The valve flywheel is slowly unscrewed, after which the gas is released. The valve is carefully removed, smoothly and without damaging the housing.

Remaining in the cylinder the condensate is poured out. Then simple technical steps remain: install a new gasket, another valve (if necessary). Finally, check for leaks.

Independent manipulations are prohibited by the rules, but in extreme cases and if you have the skills, you don’t have to wait for specialists. Some types of valves can be partially disassembled indoors and without releasing gas, for example, to replace internal seals.

Replacement of cylinder parts may be necessary at least once every two years, and, in addition, there are restrictions in terms of independent actions and storage conditions for the container

Replacing the gasket between the valve and the gearbox will take less time. It will be enough to close the flywheel, disconnect the gearbox and install a seal between its nut and the valve fitting.

Some gearboxes do not operate through a valve, but directly from the cylinder. In this case, it should be taken outside to release the gas.

Conclusions and useful video on the topic

Eliminating gas leaks using available tools and replacing the internal valve gasket:

Gas cylinder seals should be replaced at the first sign of damage or loss of seal. They are made from highly flammable materials such as paronite, fluoroplastic and special rubber. Rings are produced for containers and units of any size, so there is no doubt about the quality of the seal.

In hardware stores there are gaskets for gas cylinders of 12, 27, 50 liters and containers with less common sizes. The cylinders themselves should be stored outside residential buildings, apartments and technical floors, away from escape routes.

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