SEAL RING AND CONDUIT CONNECTOR

Abstract

It is disclosed an annular seal ring adapted for use in conduit connectors. The seal ring includes an inner sealing portion and an outer sealing portion. The sealing portions are disconnected from each other allowing them to move completely freely relative to each other during operation.

Claims

1. A conduit connector, including: a first hub (1) with a first cavity section, a second hub (2) with a second cavity section, wherein said first and second cavity sections form a cavity when the first and second hubs are connected, wherein the first cavity section includes a first protrusion (4a) with inner and outer tapering sidewalls (5a, b), the second cavity section includes a second protrusion (4b) with inner and outer tapering sidewalls (5a, b), wherein the first protrusion (4a) is facing the second protrusion (4b) when the two hubs (1, 2) are connected, a seal ring located in said cavity, characterized in that the seal ring includes an inner annular sealing portion (3a) and an outer annular sealing portion (3b), wherein the sealing portions (3a, b) are disconnected from each other allowing them to move completely freely relative to each other during operation, the inner sealing portion (3a) comprising a pair of inner annular seal lips (8a), the outer sealing portion (3b) comprising a pair of outer annular seal lips (8b), the lips (8a) of the inner sealing portion (3a) engaging the inner sidewalls (5a) of the first and second protrusions (4a, b), the lips of the outer sealing portion (3b) engaging the outer sidewalls (5b) of the first and second protrusions (4a, b), wherein the inner annular sealing portion (3a) is separated from the outer annular sealing portion (3b) by wedging action provided by the tapered sidewalls (5a, b), and wherein fluid pressure inside the connector is only acting on and affecting the inner sealing portion (3a), and fluid pressure on the outside of the connector is only acting on and affecting the outer sealing portion (3b).

2. A conduit connector according to claim 1, including a test port (12) in the cavity between the inner sealing portion (3a) and the outer sealing portion (3b) for pressure and/or temperature readings.

3. A seal ring with an inner annular sealing portion (3a) and an outer annular sealing portion (3b), characterized in that the sealing portions (3a, b) are disconnected from each other allowing them to move completely freely relative to each other during operation, the inner sealing portion (3a) comprising a pair of inner annular seal lips (8a), the outer sealing portion (3b) comprising a pair of outer annular seal lips (8b).

4. A seal ring according to claim 3 where the inner sealing portion (3a) and the outer sealing portion (3b) is manufactured from different materials giving different properties and behaviour when exposed to pressure and temperature to accommodate the different conditions on the inside and outside of the seal ring.

5. A seal ring according to claim 3 or 4, where the inner sealing portion (3a) comprises a support rib (10) and the outer sealing portion (3b) comprises a mating groove (11), the support rib (10) being adapted to interact with the groove (11) under certain combinations of pressure and temperature.

6. A seal ring according to claim 3 or 4, where the inner sealing portion (3a) comprises a groove (11) and the outer sealing portion (3b) comprises a mating support rib (10), the support rib (10) being adapted to interact with the groove (11) under certain combinations of pressure and temperature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Certain features and functions of the present disclosure will be described with reference to the following appended figures in which:

[0015] FIG. 1 is a cross section through a part of a prior art conduit connector with an annular seal ring,

[0016] FIG. 2 is a corresponding cross section through a conduit connector with an annular seal ring according to the present disclosure as unassembled,

[0017] FIG. 3 is a cross section through the inventive conduit connector as assembled,

[0018] FIG. 4 is a cross section through the inventive conduit connector as assembled when subject to an overly high differential pressure over the seal ring,

[0019] FIG. 5 is a cross section through a conduit connector holding another embodiment of the inventive seal ring, and

[0020] FIG. 6 is a perspective view of the inventive seal ring.

DETAILED DESCRIPTION

[0021] FIG. 1 is a cross section through a prior art non-load bearing self-energized conduit connector connecting a first hub 1 and a second hub 2. The conduit connector has axial symmetric geometry about the centerline A-A on the left hand side of the cross section. The left hand side is a mirror image of the right hand side. In the mating end surfaces of the hub there are machined grooves for accepting an H-shaped seal ring 3. The grooves include truncated projections with tapered sidewalls 5a, b adapted to contact inner and outer seal lips 8a, b on the seal ring. The seal ring is homogenous consisting of outer and inner sealing portions 3a, b which are firmly connected to each other through a web 7. If the internal fluid pressure in the connector is substantially higher than the external pressure, the internal pressure will exert a force on the inner lips 8a that increases the contact pressure against the protrusions 4a, b. However, this force will be transferred to the outer lips 8b through the web 7 lowering the contact exerted by these lips against the opposite sidewalls 5b of the protrusions 4a, b. This means that the sealing ability of the internal seal portion is improved, while the sealing ability against the outside of the connector is compromised. Such a high difference in pressure as described above can cause more plastic deformation to the firm web, which will further reduce the contact-pressure between the seal-lips and the grooves.

[0022] FIG. 2 illustrates a non-load bearing self-energized seal ring in a conduit connector according to the present disclosure connecting a first hub 1 and a second hub 2. In the mating end surfaces of the hub there are machined grooves for accepting an H-shaped annular seal ring 3a, b. The grooves include truncated projections with tapered sidewalls 5a, b adapted to contact inner and outer seal lips 8a, b on the seal ring. The seal ring 3a, b comprises an inner annular portion 3a and an outer annular portion 3b, which outer annular portion 3b is coaxially positioned relative to the inner annular portion 3a.

[0023] The annular seal ring consists of at least two independent annular sealing portions which are manufactured independently and joined together to a system prior to assembly. A possible assembly method is to shrink the inner annular seal portion 3a relative to the outer annular seal portion 3b.

[0024] When the seal ring is mounted into the conduit connector, the portions 3a, b become separated by the wedging action provided by tapered sidewalls 5a, b and act as independent sealing portions under normal load-conditions, as shown in FIG. 3.

[0025] FIG. 6 shows the inventive seal ring as seen in perspective with an outer seal portion 3b and an inner seal portion 3a.

[0026] If the internal fluid pressure in the connector is substantially higher than the external pressure, the internal pressure will only affect the inner annular portion 3a. As the seal ring 3a, b is in two-part form the forces exerted on the inner annular portion 3a will not be transferred to the outer annular portion 3b.

[0027] Conversely, if the external fluid pressure in the connector is substantially higher than the internal pressure, the external pressure will only affect the outer annular portion 3b. As the seal ring 3a, b is in two-part form the forces exerted on the external annular portion 3b will not be transferred to the outer annular portion 3a.

[0028] The inner annular portion 3a and the outer annular portion 3b may be produced from different materials such as different metals or metal alloys, different polymers or combinations of the above. The use of different materials in the annular portions will give different properties and behavior when exposed to pressure and temperature to accommodate the different conditions on the inside and the outside of the seal ring.

[0029] FIG. 3 also illustrates the presence of an outer support rib 10 projecting from inner annular portion 3a. On the corresponding outer annular portion 3b there is a mating inner groove 11. In an unstressed condition a slip distance exists between the outer circumference of the outer support rib 10 and the bottom of the inner groove 11. If the differential pressure over the seal ring 3 exceeds the maximum allowable value, the outer support rib 10 will contact the bottom of the inner groove 11. This will allow the inner annular portion 3a and the outer annular portion 3b to support each other preventing the seal ring 3a, b from being damaged, as shown in FIG. 4.

[0030] Alternatively, the rib 10 may be on the outer sealing portion 3b and the groove 11 may be on the inner sealing portion 3a as illustrated in FIG. 5.

[0031] FIG. 4 illustrates how the interaction between the inner sealing portion and the outer sealing portion in an assembled connector can be regained under certain combinations of designed stiffness, pressure and temperature. Specifically, here the fluid pressure inside the tubing is overly high and the inner sealing portion has yielded to the pressure. The support rib 10 is in contact with the bottom of the groove 11. This means that the inner sealing portion is supported by the outer sealing portion avoiding a collapse of the inner sealing portion.

[0032] FIG. 3 also illustrates how the hubs 1, 2 and seal ring 3a, b form a protected cavity. This cavity may be a convenient location for a pressure tapping test port 12, and for sensors for assessing the integrity of the conduit connector. There may be conducted a verification test of correct assembly without compromising the integrity of the conduit prior to start of production. Pressure and temperature sensors may be mounted in this protected cavity for monitoring pressure and temperature during operation without compromising the integrity of the conduit. Additional instrumentation may be mounted inside this cavity, such as sensors for measuring humidity. The signals from sensors and electronics inside the protected cavity may be transferred from the cavity adjacent to the production fluid.

[0033] The expression ‘conduit connector’, as used in this description, is not limited to mean only connectors connecting tubular elements. In addition the seal ring may find applications wherever two bodies are to be joined through a sealed connection, such as connecting different parts of a pressure vessel.