Rubber O-rings (GOST)

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Rubber o-rings are designed to seal the connection of various parts, both fixed and moving. These products are also used in the construction of hydraulic and pneumatic units and devices. Consider the features and classifications of sealing rubber rings according to GOST.

General information

The scope of application of sealing rubber rings is quite wide. They are used in sanitary ware, internal combustion engines, sewer systems, gas pipelines, pumps, etc.

Sealing rubber rings can have an x-shaped, round or rectangular section. However, regardless of the form, their technical characteristics must comply with the parameters established by GOST. Rubber sealing rings of round type, for example, are produced in accordance with State Standard 9833-73.

Physical characteristics of products vary depending on the intended use. Sealing rubber rings can be elastic, rigid,resistant to temperature extremes, the negative effects of aggressive environments and various chemicals.

Material

Its choice depends on the properties of the working fluid with which the product comes into contact. O-rings currently available:

• rubber;
• rubber;
• silicone;
• leather.

If the liquid with which the product comes into contact can affect it negatively, for example, oil has a destructive effect on rubber, then rubber seals are used. Why? This material is resistant to compounds found in oil.

Benefits

The main advantages of O-rings are:

1. Easy to install.
2. Durability.
3. High functionality.

In some cases, these parameters are extremely important. For example, they are of great importance when installing a sewer system.

The undoubted advantage of the products is that they do not lose their properties even after several assembly / disassembly of the structure. A seat is provided in the details of a round shape. It greatly facilitates the installation of the O-ring.

Use of rectangular products

A set of square rings is generally used to seal a static connection. It is allowed to use such products in moving parts, but having a slightrange of motion. This applies in particular to flange connections and valves.

Most often, square seals are used in pipeline connections for various purposes. Products in such cases provide optimal sealing.

Working fluid can be water (cold/hot), alkali, acid, steam, gases.

Special Options

When installing square seals, the allowable compression limit is 0.1-0.2 mm. The tightness of the connection is achieved when the ring is displaced by means of pressure in the working environment.

Each ring in the set has its own designation. It allows you to determine the scope and possibility of using products in a particular situation. The first number is the stem diameter, the second is the cylinder, and the third is the ring height.

Rubber O-Ring (GOST 9833-73, 18829-73)

As a rule, such products are used in joints of static structures. However, in some cases it is allowed to use in dynamic connections, if there is a reciprocating, rotational, oscillatory movement.

Classification of products is carried out depending on the type of material:

• Rubber sealing rings of round section according to GOST 18829-73. Such products are used in pneumatic, hydraulic, fuel installations.
• Heat-frost-acid-alkali-resistant seals (TMKShch). These rings are used in pipelines transporting alkali, acid, other chemicals, includingnumber at elevated temperatures.
• Rubber rings according to GOST 9833-73. These products are intended for use in the food industry, i.e. they may come into direct contact with food.
• Oil-resistant (MBS) seals are used, respectively, in equipment whose working fluids are oil and gasoline.

Main parameters

The inner diameter of the rubber O-ring varies from 1mm to 2000mm. The sectional area can be 0.5-20mm. For convenience, the corresponding designations are applied to the products.

For example, if we talk about a set of seals for the internal sewer system:

• the first 3 digits indicate the diameter of the stem on which the ring is put on;
• the next 3 are the diameter of the cylinder (the product is inserted into it);
• product thickness is indicated by the seventh and eighth digits;
• accuracy class - ninth;
• rubber type - tenth.

In some cases, a slight deviation of the actual parameters from those given in the marking is allowed.

Terms of Use

Rubber seals can be used at temperatures from -60 to +250o C. The exact figures depend on the type of material.

If we talk about pressure, then with a static connection, it should not be more than 500 atm, and if dynamic (especially if the working fluid is lubricant, fuel, water, oil) - no more than 350 atm. If rings are used in air installations forseals of the movable joint, the pressure cannot exceed 100 atm.

Cuffs

These products are used where rings cannot be installed. They are used, in particular, in the joints of movable structures of rods and axles that perform rotational or translational movements.

Rubber cuffs have outer and inner diameters. Special reinforcement is used to increase strength.

Cuffs are classified like rings, depending on the application:

• Reinforced, the parameters of which correspond to the State Standard 8752-79. They are used in joints of parts in mineral oil, water, diesel fuel.
• Unreinforced, the indicators of which correspond to the State Standard 6678-72. These cuffs are used in pneumatic units, compressors and other similar installations.
• Unreinforced, the characteristics of which correspond to the State Standard 14896-84. Such products are used in hydraulic devices.
• Cuffs made according to TU 38-1051725-86. They are used when sealing nodes that move progressively.

Rings for storm sewer system

When installing such a sewer, it is not advisable to use rubber seals. Silicone rings can provide high tightness of connections. They withstand temperatures from -60 to +200o C.

The advantage of silicone seals is their low (compared to rubber products) price. They arequickly gained popularity in the market. This is due to high rates of elasticity, wear resistance, strength. In addition, these products are available in a variety of sizes.