Under-balanced seal ring

A seal ring for providing a seal between first and second flanges in a piping system, wherein each flange has a face in which an annular ridge is provided between concentric grooves, the seal ring comprising:

• a circular ring that consists of inner and outer hollow cylinders and a web that connects the inner and outer hollow cylinders together, wherein the circular ring has upstream and downstream sides, a radially inner sealing portion provided by the inner hollow cylinder, a radially outer sealing portion provided by the outer hollow cylinder,
• wherein the inner and outer hollow cylinders have non-uniform wall thicknesses due to the sloping sides,
• wherein the web extends radially and connects the inner and outer sealing portions together,
• wherein the web and the inner and outer sealing portions are designed and sized so that the annular ridge of the first flange can be received between the inner and outer sealing portions on the upstream side of the circular ring and the annular ridge of the second flange is received between the inner and outer sealing portions on the downstream side of the circular ring, without any other sealing element,
• wherein the web and the inner and outer sealing portions are designed and sized so that the inner and outer sealing portions on the upstream and downstream sides of the circular ring sealingly engage the annular ridge of the first and second flanges, respectively, without any other sealing element, wherein the circular ring has a radius and a longitudinal length that is perpendicular to the radius and extends from the upstream side to the downstream side, and wherein the longitudinal length of the inner sealing portion is greater than the longitudinal length of the outer sealing portion, and wherein the web has a first longitudinal thickness proximal to the inner hollow cylinder and a second longitudinal thickness proximal to the outer hollow cylinder, and a sloping transition or a shoulder between the first and second longitudinal thicknesses.

A seal ring for providing a seal between first and second flanges in a piping system, wherein each flange has a face in which an annular ridge is provided between concentric grooves, the seal ring comprising:

• a circular ring having upstream and downstream sides, a radially inner sealing portion, a radially outer sealing portion and a web that extends radially and connects the inner and outer sealing portions together integrally,
• wherein the web and the inner and outer sealing portions are designed and configured so that the annular ridge of the first flange can be received between the inner and outer sealing portions on the upstream side of the circular ring and the annular ridge of the second flange is received between the inner and outer sealing portions on the downstream side of the circular ring,
• wherein the web and the inner and outer sealing portions are designed and configured so that the inner and outer sealing portions on the upstream and downstream sides of the circular ring sealingly engage the annular ridge of the first and second flanges, respectively,
• wherein the circular ring has a radius and a longitudinal length that is perpendicular to the radius and extends from the upstream side to the downstream side, wherein the longitudinal length of the inner sealing portion is greater than the longitudinal length of the outer sealing portion, wherein the inner sealing portion and the outer sealing portion of the seal ring have sloping sides that face one another,
• wherein the inner and outer sealing portions are concentric hollow cylinders that have non-uniform wall thicknesses due to the sloping sides,
• and
• wherein the web has first and second portions that have different thicknesses and a sloping transition or a shoulder between the first and second portions for allowing non-uniform movement of the first flange with respect to the second flange.

A seal ring for providing a seal between first and second flanges or hubs in a piping or flow-containment system, the seal ring comprising:

• a ring having upstream and downstream sides, a radially inner sealing portion, a radially outer sealing portion and a web that extends radially and connects the inner and outer sealing portions together integrally,
• wherein the inner sealing portion and the outer sealing portion of the ring have opposing sloping sides that face one another, wherein the ring does not have any secondary seal elements,
• wherein the inner and outer sealing portions are concentric hollow cylinders that have non-uniform wall thicknesses due to the sloping sides,
• wherein the seal ring has a diameter that is coaxial with the web and a longitudinal length that is perpendicular to the diameter and extends from the upstream side to the downstream side, wherein the longitudinal length of the inner sealing portion is not equal to the longitudinal length of the outer sealing portion, and
• wherein the web has a first longitudinal thickness proximal to the inner sealing portion and a second longitudinal thickness proximal to the outer sealing portion, and a sloping transition or a shoulder between the first and second longitudinal thicknesses.