phosphoric acid h3p04

When they are subjected to hot & pressured oil, or hot & pressured gas, they will compress. These seals reduce in size and become more compact. Afterward, they store the mechanical energy generated by the heat and pressure, which is why they can maintain a leak-proof mating surface.

An outer case, a body made of metal or provided with a rubber layer

Nitrile Butadiene Rubber (NBR, nitrile)

No single physical property of rubbers is responsible for the successful performance of an oil seal or ‘O’ ring. The ultimate tensile strength, breaking elongation, modulus, shore hardness, creep and stress relaxation in tension and compression loads are all important physical properties that characterize a seal or ‘O’ ring. Compression strength and set together with stress relaxation or decay are important for effective sealing. The difference in these properties in a swollen seal is highly critical. An optimum swelling value in a fluid medium is a desirable feature. De-swelling decreases the seal pressure against the wall of the housing where the seal is fixed, leading to leakage. Over swelling minimizes the physical properties of the rubber. Seals made of polysulfide rubbers have extreme fuel resistance but undesirably high compression set. The effect of temperature on the seal is an important factor. Swelling under stress can increase at higher temperatures and a suitable compounding technique should be adopted to reduce this effect.

Figure 4: Shaft end chamfer

Table 5: The major special seals, their shapes, and their features

ERIKS type M (type B according to the DIN standard) has a single metal casing and rubber sealing lip. Since the casing is made of metal, it must be fitted in a well-finished, undamaged groove. Large volumes of oil seals with metal casings are often cheaper, which is why they are often used as original equipment in machines. However, if an oil seal has to be replaced, types with a rubber exterior (type R or RST) are easier to fit. Type MST is similar to M and commonly used. The difference is the dust lip in the MST oil seal that prevents dust and dirt reaching the sealing lip, and extends its service life in dusty environments.

For more detailed information, please see the following:

Names and functions of seal components　

(peripheral speed)

• SIM method to prevent the spring from falling off (integral molding of spring and rubber)

Lubricant Amount - Seals will always perform best when lubricated, however in some machines there are more likely to be dry spells. For these cases, selecting a leather or PTFE seal will be beneficial, as both can operate with less lubrication than others.

They are best known for their bright light emission that is far reaching. Their tungsten is encased in a quartz tube filled with xenon gas. They may require more power when turned on but use much less of it to maintain brightness. Moreover, they have a longer lifespan compared to the halogens. They may seem better but they also present some limitations such as being more expensive as far as manufacturing and replacement is concerned. They are not easy to manufacture from their complex design. Their bright light cause a blinding effect to oncoming traffic which is undesirable and can cause dangers on roads.