Rubber o- rings are designed to seal the connection of various parts, both stationary and moving. These products are also used in the construction of hydraulic and pneumatic units and devices. Consider the features and classification of rubber sealing rings according to GOST .
General information
The scope of the sealing rubber rings is quite wide. They are used in sanitary products, ICE, sewer systems, gas pipelines, pumps, etc.
Sealing rubber rings can have an x-shaped, round or rectangular cross-section. However, regardless of the form, their technical characteristics must comply with the parameters established by GOST. Round rubber rings , for example, are manufactured according to Gosstandart 9833-73.
The physical characteristics of the products vary depending on the purpose of their use. Sealing rubber rings can be flexible, tough, resistant to temperature changes, the negative effects of aggressive environments and various chemicals.
Material
His choice depends on the properties of the working fluid with which the product is in contact. O-rings are currently available :
- rubber ;
- rubber;
- silicone;
- leather.
If the fluid with which the product is in 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 present in oil.
Benefits
The main advantages of sealing rubber rings are:
- Easy to install.
- Durability.
- 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. In the details of a round shape, a seat is provided. It greatly facilitates the installation of the o-ring.
The use of rectangular products
A set of square rings is usually used to seal a static joint. It is allowed to use such products in moving parts, but having a small amplitude of motion. This is especially true for flanged joints and valves.
Most often, square gaskets are used in pipelines for various purposes. Products in such cases provide optimal sealing.
The working fluid can be water (cold / hot), alkali, acid, steam, gases.
Special parameters
When installing square seals, the permissible compression limit is 0.1-0.2 mm. The tightness of the connection is achieved when the ring is displaced by pressure in the working medium.
Each ring in the set has its own designation. It allows you to determine the scope and possibility of using products in a specific situation. The first digit indicates the diameter of the rod, the second indicates the cylinder, and the third indicates the height of the ring.
O-ring, rubber, round cross-section (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 joints, if there is a reciprocating, rotational, oscillatory motion.
Product classification is carried out depending on the type of material:
- Rubber O-rings of circular cross-section according to GOST 18829-73. Such products are used in pneumatic, hydraulic, fuel installations.
- Heat-morozoic acid-alkali resistant sealants (). These rings are used in pipelines transporting alkali, acid, and other chemicals, including at elevated temperatures.
- Rubber rings according to GOST 9833-73. These products are intended for use in the food industry, that is, they can be in direct contact with the products.
- Oil and gas resistant (MBS) seals are used, respectively, in equipment whose working fluids are oil and gasoline.
main parameters
The inner diameter of the rubber sealing round ring varies from 1 to 2000 mm. The cross-sectional area may be 0.5-20 mm. For convenience, appropriate designations are applied to the products.
For example, if we talk about a set of seals for an internal sewer system:
- the first 3 digits indicate the diameter of the stem on which the ring is worn;
- the next 3 - cylinder diameter (the product is inserted into it);
- the thickness of the product is indicated by the seventh and eighth digit;
- accuracy class - ninth;
- type of rubber - 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 +250 . The exact indicators 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 it is dynamic (especially if the working fluid is lubricant, fuel, water, oil) - no more than 350 atm. If rings are used in air installations to seal the movable joint, the pressure may not exceed 100 atm.
Cuffs
These products are used where rings cannot be installed. They are used, in particular, in joints of movable structures from rods and axles that perform rotational or translational movements.
Rubber cuffs have outer and inner diameters. To increase the strength, special reinforcement is used.
Cuffs are classified, like rings, depending on the scope of application:
- Reinforced, the parameters of which correspond to Gosstandart 8752-79. They are used in compounds of parts found in mineral oil, water, diesel fuel.
- Unreinforced, indicators of which correspond to Gosstandart 6678-72. These cuffs are used in pneumatic units, compressors and other similar installations.
- Unarmoured, the characteristics of which correspond to Gosstandart 14896-84. Such products are used in hydraulic devices.
- Cuffs made according to TU 38-1051725-86. They are used for sealing nodes moving progressively.
Rings for the storm sewer system
When installing such a sewer, rubber seals are not practical. High tightness of joints can provide silicone rings. They withstand temperatures from -60 to +200 o C.
The advantage of silicone seals is their low (compared to rubber products) price. They quickly gained popularity in the market. This is due to high rates of elasticity, wear resistance, strength. In addition, these products come in a variety of sizes.