Sealing Ring Has Excellent Heat Resistance, Cold
Sealing Ring damage can not be grinding, welding, bonding and heat treatment and other processes to repair, or seal repair as replacement, then the seal should be replaced or re-surfacing.
The so-called seal damage is serious, refers to the ring serious mechanical damage and corrosion; seals loose and fall off; seals have a large surfacing defects and cracks; seal the gap is too large or dropped; sealing surface height is too low ; Poor quality of heat treatment, low performance, into the hardness is too low, surface peeling and other serious defects, there are one of these serious defects, the general use of replacement or welding new sealing surface.
Replace the new sealing ring, to solve some technical problems, according to the original design or working conditions selected seal material, to determine the size of the connection of the seal, to use the seal of the mechanic process.
The replacement of the seal is a very technical, work with the work of the work. Sealing ring replacement after removal, production and assembly of three processes. Rubber, plastic manufacturing ring, generally inlaid, bolt fixed, the replacement is more uniform, it is difficult to replace the compression molding, rolling and welding fixed form.
The main performance of the ring
In addition to the general requirements of the sealing ring material, the seal should also pay attention to the following conditions:
(1) elastic and resilient;
(2) appropriate mechanical strength, including expansion strength, elongation and tear strength.
(3) stable performance, in the medium is not easy to swell, heat shrinkage effect (Joule effect) small.
(4) easy to shape, and can maintain the precise size.
(5) does not corrode the contact surface, do not pollute the media and so on.
The most suitable and most commonly used material to meet the above requirements is rubber, so the seals are mostly made of rubber. Rubber variety, and there have been new varieties of rubber, design and selection, should understand the characteristics of a variety of rubber, a reasonable choice.
The material and application of sealing ring
First, NBR nitrile rubber seal: suitable for petroleum hydraulic oil, glycol hydraulic oil, polyester oil, gasoline, water, silicone grease, silicone oil and other media used. Is the most widely used, the lowest cost rubber seals. Not suitable for use in polar solvents such as ketones, ozone, nitrohydrocarbons, MEK and chloroform. General use temperature range of -40 ~ 120 ℃.
Second, HNBR hydrogenated nitrile rubber seal: with excellent corrosion resistance, tear resistance and compression properties, ozone resistance, resistance to sunlight, weather resistance is better. Better than the nitrile rubber wear resistance. Suitable for washing machines, automotive engine systems and the use of new environmentally friendly refrigerant R134a refrigeration system. It is not recommended for use in alcohols, esters or aromatic solutions. General use temperature range of -40 ~ 150 ℃.
Third, SIL silicone rubber seal: with excellent heat resistance, cold, ozone resistance, resistance to atmospheric aging performance. Have a good insulation performance. But the tensile strength is worse than the general rubber and not oil resistance. Applicable to household appliances such as electric water heaters, irons, microwave ovens and so on. Also applies to a variety of contact with the human body supplies, such as kettles, drinking fountains and so on. It is not recommended for use in most concentrated solvents, oils, concentrated acids and sodium hydroxide. General use temperature range of -55 ~ 250 ℃.
Fourth, VITON fluorine rubber seals: high temperature resistance is better than silicone rubber, excellent weather resistance, ozone resistance and chemical resistance, cold resistance is bad. For most of the oil and solvents are resistant, especially acids, aliphatic hydrocarbons, aromatic hydrocarbons and animal and vegetable oils. Suitable for diesel engine, fuel system and chemical plant sealing needs. It is not recommended for use in ketones, low molecular weight esters and mixtures containing nitrates. General use temperature range of -20 ~ 250 ℃.
5, FLS fluorine silicone rubber seal: its performance both the advantages of fluorine rubber and silicone rubber, oil, solvent, fuel-resistant oil and high and low temperature are good. Resistance to oxygen-containing compounds, aromatics-containing solvents and chlorine-containing solvents. Generally used for aerospace, aerospace and military use. Do not recommend exposure to ketones and brake oil. The general use of the temperature range of -50 ~ 200 ℃.