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Have You Considered All The Factors Of Choosing Spiral Wound Gasket?

Feb 04, 2020


SPIRAL WOUND GASKET are seals that wrap non-metallic fillers of a certain width (e.g. expansion graphite, teflon or special asbestos, asbestos-free paper) and cold-rolled steel strips continuously, and are fixed by spot welding at the beginning and end, making them winding gaskets. Depending on the flange type, the inner ring, outer ring or inner ring can be placed on the seal (basic type gasket), i.e. it becomes an inner ring type, with an outer ring type and an inner and outer ring type winding gasket.   The inner and outer ring metal winding pad sits excellent stress compensation characteristics and sealing properties, suitable for high temperature and high pressure pressure and pressure temperature alternating frequent flange seal: teflon as the filling belt winding gasket, can be applied to strong acid, alkali and other harsh media and high cleaning requirements of the static sealing site.   Inside and outside ring metal winding pad sit udling pad sit dulling pad situated in machinery, metallurgy, electricity, shipbuilding and pipelines, valves, pumps, pressure vessels, condensers, towers, human holes, hand holes and other flange connections, for static sealing, due to high mechanical strength, easy to use, good compression back elasticity, more suitable for application in violent temperature metastases   

These factors should be taken into account when choosing SPIRAL WOUND GASKET.   

  1. Compression and recovery rates

    Compression rate refers to the influence of thickness under a specific load, and recovery rate refers to the degree of increase in thickness after the load is eliminated. The high compression ratio of the gasket indicates that it can be used on irregular surfaces, the flange surface is more adaptable, increases friction, makes the gasket not easily burst, and reduces the possibility of leakage.   The response rate indicates the elastic performance of the gasket, and the gasket with a high response rate generally requires a greater pressure force to maintain a good seal.   

2. Chemical adaptability   

SPIRAL WOUND GASKET can be corrupted and decomposed by chemical media, resulting in severe leaks, so gaskets must be adapted to the medium. Just because the washer enters the inner diameter of the pipe during installation, the washer is rarely corroded, so the washer does not fail quickly after assembly, and it takes some time for the media to pass through the entire washer.   Some SPIRAL WOUND GASKET can expand in some media, in which case the gasket can still be sealed in a short period of time, even if the gasket is incompatible with the medium. The safe choice is that gaskets cannot be eroded by media, so most gasket manufacturers offer chemical properties (PValues) for their products.   

3. Sealing capacity   

All gaskets have leaks. The ideal state for washer seals is zero leakage. In any case, good sealing performance can reduce product losses, improve safety and save costs. If the gasket leaks at room temperature, the condition may be more severe at high temperatures. The 0.8mm thick gasket test can be selected. The thinner the gasket, the better the sealing capacity, because the less material the media can pass through. In practical applications, many of the use of 1.5mm or 3mm thickness gaskets, coupled with the effect of temperature, so the leakage rate is higher. If the medium is gas, then the leakage rate is higher because the gas molecules are smaller and easier to pass through around the gasket and the gasket.   


The maximum pressure that gaskets can withstand is closely related to temperature, and most gaskets cannot be applied at both temperature and pressure limits. At high temperatures, the pressure capacity of the gaskets is reduced, and in the same case, the temperature tolerance is reduced at high pressure.

5. Gasket creep   

Creep will result in a reduction in load, if the load is reduced or lost, the gasket and the flange surface friction is reduced, prone to leakage or even gasket blowing out. If the gasket creeps largely, it will be necessary to tighten the flanges regularly, increasing the labor intensity.   6. Temperature   Temperature is one of the key factors in the selection of gaskets, and the temperature affects different material shims. At high temperatures, the filler may evaporate, the elastomer cures to harden, the gasket is prone to loss of elasticity and brittleness at low temperatures, and fastening flanges generally do not improve the sealing performance but break the gasket. Gaskets for very low temperatures are generally kept clean and dry.   

7. Gasket thickness  

 If chemical adaptability, temperature, and pressure have been determined at the time of selecting the washer, the maximum thickness of the washer is still determined. In many cases, it is best to choose the thinnest washer. Because the thinner, the smaller the contact area with the medium, the smaller the leak path of the media through the washer, and the higher the pressure capacity. And it's more economical. If the flange surface is rough, we recommend using a thick eroding to compensate for the unevenness of the flange surface for sealing effect.