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The Washers Have Good Elasticity And Restorability
Aug 21, 2017

Although the gasket is humble, but it is a vital role, many types of gaskets, different sizes, different materials, play a different role.

A gasket is a mechanical seal between two objects, usually used to prevent two things; the correct choice of sealing gasket is the key to ensure that equipment is no leakage; in the use of gaskets, the pressure and The temperature of the two are mutually constrained, with the second, Seals the choice of gasket should be considered when the factors; 1. have good flexibility and restorability, can adapt to pressure changes and temperature waves; 2. have appropriate flexibility, The surface is well fitted ;; 3. Do not pollute the process medium ;; 4. have enough toughness and not due to pressure and tightening force caused by broken ring

First, the role of the gasket and the actual use of the situation

A gasket is a mechanical seal between two objects, and is often used to prevent stress, corrosion, and natural heat expansion and contraction between two objects.Seals  As the machined surface can not be perfect, Seals use the washer to fill the irregularities.

Proper use of sealing gaskets is the key to ensuring no leakage of equipment. For the same conditions, there are generally a number of gaskets to choose from. Must be based on the physical properties of the media, pressure, temperature and equipment size, operating conditions, the length of continuous operation cycle, etc., Seals a reasonable choice of gaskets, strengths and weaknesses, give full play to the characteristics of various gaskets.

In the use of gaskets, the pressure and temperature are mutually constrained. As the temperature increases, the gasket material softens, creep, stress relaxation, and the mechanical strength decreases as the equipment runs for a period of time The pressure is reduced. vice versa. For example, Seals high pressure asbestos rubber sheet washer XB450 in water, steam medium, the use of temperature 450 ℃, pressure <6MPa (the material for the sealing performance test, in the 440 ℃ ~ 450 ℃, 12MPa steam for 30 minutes). But in the long-term practical use, the temperature reached 450 ℃, can seal the pressure of only 0.3 ~ 0.4MPa. For the strong permeability of the gas medium is only 0.1 ~ 0.2MPa.

Second, select the gasket should be considered when the factors

1. Have good flexibility and restorability, Seals can adapt to pressure changes and temperature fluctuations;

2. With the appropriate flexibility, with the contact surface is a good fit;

3. does not pollute the process media;

4. have sufficient toughness and not due to pressure and tightening force caused by broken ring;

5. Low temperature does not harden, Seals shrinkage is small;

6. Processing performance is good, easy to install, compact;

7. Unbonded sealing surface, easy to disassemble;

8. Cheap, long service life.

Third, the selection of gasket recommendations

1. High-risk occasions must meet the good sealing, safe and dangerous. High-risk occasions, high temperature, high pressure, steam, toxic media, flammable, explosive. Washers should use the performance of the metal ring pad, tooth-shaped combination of pads, winding washers, wave tooth composite pad. Seals Wrapped washers are guaranteed with inner and outer reinforcement rings. Wave tooth compound gasket can be used as the preferred product, because its comprehensive performance is the best, affordable. Where the working conditions are not changed, the toothed pad and the metal flat pad are used. Metal ring pad by the cost of manufacturing and other effects, Seals after application is not ideal to avoid selection.

2. Asbestos-containing sealing material should be used with or without, because such materials are generally only used for low-parameter conditions such as ordinary water, steam and oil for undesirable applications. Low-parameter occasions can be used high-strength graphite pad instead of asbestos rubber sheet washers. Seals Although the price is expensive but the performance is good, is the asbestos rubber sheet washers ordinary alternative materials.

3. With pressure, temperature changes, vibration, shock occasions (such as pumps and compressors and other moving equipment flange connection) to use a good rebound performance of the wound gasket and wave composite pad.

4. Heat medium heating system selection of high strength graphite composite pad, as far as possible without asbestos rubber sheet gasket for seals. Seals Should be used will not swell and expansion, anti-medium permeability of graphite as the main winding type gasket, wave tooth composite pad.

5. Pharmaceutical and other industries, and the production of materials in contact with the pipeline and process equipment, seals as far as possible without the use of asbestos rubber sheet gasket material seals. The main material is PTFE gasket gasket is ideal, Seals especially the coating pad better performance to overcome the PTFE gasket flat pad easy to cold flow, no elastic shortcomings, with clean and not pollution, better flexibility.

6. General corrosive media occasions can choose stainless steel skeleton of the wound washers and wave tooth composite pad. Strong corrosion conditions with flat and PTFE coated gaskets. Low - pressure low - temperature high - strength graphite composite pad.