Fluororubber sealing ring consists of one or more parts of the annular cover, fixed on one ring or gasket of the bearing and contact with another ring or gasket or form a narrow labyrinth gap, to prevent oil leakage and the invasion of external objects. Fluoro rubber sealing ring is made of copolymer of vinyl fluoride and hexafluoron.

Fluoroelastomer is a copolymer of vinyl fluoride and hexafluorene. Depending on its molecular structure and fluorine content of fluorine elastomer chemical resistance and low temperature resistant performance is also different. Fluoro elastomers based on its excellent flame retardancy, excellent air tightness, high temperature resistant, resistant to ozone, weather resistance, oxidation resistance, resistance to mineral oil, fuel oil, hydraulic oil, aromatic and many organic solvents and chemicals are known for their performance.

For general brands, the service temperature under static seal is limited to approximately -26 ° c (-15 ° f) to 282 ° c (450 ° f). Although it may be used for short periods at 295 ° c, its service life is shortened when the temperature exceeds 282 ° c. The most suitable temperature for dynamic sealing is between -15℃ and 280℃. Low temperature can reach -40℃.

The conventional wisdom is that the more O - ring seal is squeezed (that is, deformed relative to its "squeeze" state), the tighter the seal. More extrusion equals o-ring, which matches the greater force between the hardware - i.e., liquid, gas and dry powder that would otherwise flow from the rubber seal to the matching hardware.

This is squeezed more and an O ring tends to hold its force (and therefore seal better) longer than an O ring that is squeezed less. The failure of an elastomer to maintain its "push back" force over time is known as compression variability. An elastomer with a high compression permanent deformation (usually more than 80%) no longer returns to its original uncompressed shape when it is not squeezed. However, the assumption that increasing the squeeze on the o-ring will result in a better seal may not always be correct, depending on other factors. These include:

Install the damage

The more forcefully you squeeze the o-rings during the installation, the more likely you are to pinch them because of the way leaks are created. This was found when parker compared the behavior 2 finite element models used to predict the mounting of the O - rings at 40% and 25% extruded. Sealing ring in fluororubber sealing ring O - ring compression is not the more the better 40%, pinching matching parts between the O - ring is difficult to avoid, and in 25% of the installation clamping is actually eliminated.

Mating hardware damage

The relationship between the amount of non-extrusion and the compression load required to maintain the extrusion is linear. In fact, compression loads rise by more than 30% of the extrusion much faster. The o-ring takes almost two and a half times as much load to compress to 40 percent as it does to 25 percent. This level of compression load can flatten or deform lightweight or brittle mating parts.

application

Although many variables affect the form, fit and function of the seal ring, the rear leak-free seal is the most important parameter which is the amount of extrusion applied. However, as these data show, the ideal amount of extrusion itself is subject to many factors. You can't just assume that more is better.

Keep in mind that other factors can cause o-ring seals to perform poorly, such as thermal degradation, chemical interactions, gas penetration, mechanical damage such as extrusion or wear, or elastic loss of low temperature. In these cases, adjusting the amount of extrusion is unlikely to solve the problem.