Vulcanizates of several fluoroelastomers, listed in Table 14.1, were exposed to a standard 5W-30 engine oil, ASTM Service Fluid 105, for up to 6 weeks at 150°C (302°F).⁵ The oil was changed weekly, but was not aerated. Retained elongation was measured after exposure for 1, 2, 3, and 6 weeks; data are shown in Fig. 14.3. The results indicate that bisphenol-cured FKM-A500 VDF/HFP copolymer, FKM-B600 VDF/HFP/TFE terpolymer, and peroxide-cured FEPM-7456 TFE/P/VDF terpolymer lost most of their original elongation over the course of the test exposure, indicating considerable additional cross-linking occurred by reaction with amine- and phenol-containing oil additives. The other fluoroelastomers showed better retention of elongation, being much less susceptible to additional crosslinking. Note that FEPM-7456 contains a high level of VDF (about 30%), while FEPM-7506 contains a relatively low VDF level (10–15%) to serve as cure site for bisphenol curing. The other FEPM types contain no VDF.

Installation

Regular inspection and maintenance of car engine head gaskets and automotive rubber gaskets are essential to identify signs of wear, damage, or leakage. Proper replacement of worn or damaged gaskets is crucial for maintaining the integrity and performance of the vehicle's systems. Adhering to recommended service intervals and using high-quality replacement components are essential for optimizing the performance and longevity of the vehicle's gaskets.

Place the ruler or straight-edge on edge diagonally across the head and block and look for gaps showing light anywhere between the ruler and block.

Motor oils typically include a few additives which can make up between 5% and 30% of the oil. These additives help enhance the performance of the oil. Motor oils can include the following additives:

By preventing lubricants from escaping, they protect key components of machinery from being damaged by leaks of various fluids. Everything from car engines to assembly machines use these oil seals to remain free from any harmful interactions that can cause serious and expensive damage to any of their critical parts.

Under the action of the skeleton oil seal, the rigidity of the oil film just makes the oil film and the air contact end form a crescent surface, which prevents the leakage of the working medium and realizes the sealing of the rotating shaft. The sealing ability of the oil seal depends on the thickness of the oil film on the sealing surface. If the thickness is too large, the oil seal will leak; if the thickness is too small, dry friction may occur, causing the oil seal and shaft to wear; if there is no oil film between the sealing lip and the shaft, it is easy to cause heat and wear. . Therefore, when installing, it is necessary to apply some oil on the sealing ring, and at the same time ensure that the skeleton oil seal is perpendicular to the axis line. If it is not perpendicular, the sealing lip of the oil seal will drain the lubricating oil from the shaft, which will also lead to excessive sealing of the lip. wear. During operation, the lubricant in the casing seeps out a little, so that it is ideal to form an oil film on the sealing surface.

Cover any sharp corners on the machinery that may come in contact with the o-ring. This will ensure that the o-ring is not damaged in the process of installation.

Dynamic seals called bearing isolators are used to shield bearings from external impurities. They are revolving (rotor) and stationary (stator) elements. O-rings or strong seals are used in some bearing isolators, while they are constructed like labyrinths in others.

These cassette seals are widely used in wheel-end applications, such as the axles of agricultural machinery or off-road trucks.

BS