Hollow mechanical seal rings

Posted by jj on February 12th, 2020

According to the first aspect of the present invention, the mechanical sealing ring has a hollow cross-section, an opening at its radial innermost side, and a limb that normally points to the radial innermost side.The radial outermost area of the cross section is provided with steel bars to locally increase its ring strength.A known form of sealing ring has a C-shaped radial cross-section, and the opening side of C is directed to the center of the ring.

Another known seal is the \"elliptical seal\" (trademark) described in the UK patent specification 2187805, which includes a radial cross-section with a modified parabolic shape with a convergence edge.Another known seal is GB 2038961, in which the limbs of the sealed cross section extend out-Turn your lips and form omega-Shape section.The above-The mentioned sealing is very successful in many static sealing applications, but it is not always completely successful in meeting the requirements of sealing equipment and pipelines used in the natural gas field, and the pressure is usually in the area of 10000 PSI, may exceed 30000 PSI.

One reason the seals are known to fail when the sealing pressure is great is that they lack ring strength.Because of this, the sealing rings expand under the Applied internal fluid pressure until they no longer expand because of the limitations imposed on the grooves in which the SEALs are located.During this change in the diameter of the sealing ring, the area in which the surface of the sealing ring is in contact with the joint surface to be sealed is subjected to wear, making the surface rough, in most cases, it is impossible to establish a satisfactory seal.

If the thickness of the sealing ring metal increases, in order to increase the ring strength, since the seal is made of metal with a constant thickness, the flexibility of the seal is greatly reduced.This then requires greater bolts and greater torque to compress the seal and make it impossible for the seal to cope with the rotation of the flange to be sealed, I .E.e.The loss of the secondary fluid, which may occur under the pressure of the contained fluid.

The purpose of the invention is to provideThe incentive metal seal is able to overcome the said shortcomings of the known seal, especially the ability to provide a reliable seal to the fluid at very high pressure.According to the first aspect of the present invention, the cross section of the mechanical sealing ring is hollow, opening on its radial inner side, and there is a converging limb area on this side, the outermost area of the radial direction provides a locally enhanced ring strength.Preferably, the reinforcement of this outermost area is provided by a material of greater thickness, rather than the radial inner limb area in use engaging with the surface to be sealed.

The material thickness in the outermost area of the radial direction increases, resulting in an increase in ring direction strength, thus resisting the expansion of the seal in use, while the thickness of the internal area is smaller, includes flexible limbs in contact with the surface to be sealed, providing sufficient flexibility.Therefore, the relative movement of the sealing and sealing surface is reduced or eliminated so that the sealing is not subject to wear and roughness, but the load required to compress the seal is not significantly increased and the seal remains flexible enough, to adapt to the dislocation and non-parallel of the sealed surface.According to the above, in this mechanical sealing ring, the strengthening of the radial outermost area is provided by increasing the thickness of the ring material in the area;This thicker area is shaped into an outer edge or heel surface that provides an axial width usually parallel to the axis of the ring;The radial most medial free end of the limb region has an axial outward protruding tip that provides the maximum axial size of the ring in a relaxed state;The limb area is on the radial exterior of the projection, with an area of reduced axial thickness, providing a priority bending point at the end of the limb area during axial compression.