Working condition Hydraulic O-rings

 

Hydraulic O-ring seal is the easiest and most common type is one of a wide range of static and dynamic applications. O-ring groove design of hydraulic O-ring is relatively simple - a groove shape by the developed rules to obtain an economical and reliable sealing. Basically, an O-ring seal is of circular cross-section into a resilient O-ring groove design, there is provided an initial compression. O-ring hydraulic compression force required to cross-sectional diameter and hardness results. Stretch the O-ring by reducing the cross-section, which reduces the potential impact of the sealing O-ring seal compression.

 

Radial squeeze O-ring is provided and maintained its friction between the location of the installation groove. Engineered to deform a rubber compound flows upward to the extrusion gap, which is completely sealed to prevent leakage, until the pressure applied is sufficient to overcome the friction and deformation of the O ring on the small extrusion gap (assuming the rubber has reached its pressure movement restrictions, further increasing the force would lead to the failure by cutting or squeezing).

 

Hydraulic O-ring at zero or very low pressure, natural rubber compound provides a resilient seal. Sealing performance can be improved by increasing the radial pressing. This increase may have a negative impact in the extrusion of high pressure dynamic seal.

 

The possibility of seal extrusion is not limited to dynamic applications. Axial static applications, in tension mounting bolts can be opened under high pressure extrusion gap sufficient to allow leakage.

 

When pressure is applied, hydraulic O-ring moves to the low pressure side of the slot. Sealing pressure is transmitted to the surface to be sealed, which is actually equal to the initial fluid pressure ratio of the amount of interference exerted high pressure. Stress interference seals and mating surfaces caused by the applied pressure increases between. While this situation persists, hydraulic O-ring will continue to function reliably and spread up to several hundred pounds of force, assuming hydraulic O-ring option is the correct size and the groove to be processed into the appropriate size.

 

As the pressure increases, the deformation is exaggerated ring, ring the final extruded part to the extrusion gap. If the extrusion gap is too large, then it is completely extruded from a high pressure seal will fail.

 

When the pressure is released, the rubber compounds results in a resilient O-ring hydraulic return to its natural shape, similar to the preparation period. Increasing the species would be bigger as a result of the expansion of rubber, since the sealing material and fluid compatibility heated. The tank must be the correct size to allow for the maximum swelling rubber compound, otherwise the component will develop a very high stress.

 

These materials, in its normal operating temperature, it is almost impossible to compress and have a very low modulus of elasticity. Can change their shape (rather than their size) and radial squeezing imposed across the slot will result in an increase of the length of the seal.

 

When sufficient force is applied, O-ring will move toward the low-pressure side, the contact surface until the groove. Additional pressure or force to deform the O-ring toward the hydraulic extrusion gap. O-ring will initially deform as "D" shape. This modification will increase by 70% -80% of the initial surface contact area of ??the cross section. Surface contact area under high pressure O-ring is about twice the original geometry at zero pressure.

 

Internal pressure is limited by space and seal hardness (some of the data given in the figure above) to determine. In practice, the gap is usually specified for a given size and application of the ring. If you work at a low temperature, it may be necessary to reduce the depth to compensate for shrinkage of the gland ring, and provide the necessary squeeze shrinking size.