Patent Application
20150115535
The subject matter disclosed herein generally relates to elastomeric seals.
Conventional sealing elements (e.g., seals) utilized to, for example, create water and/or air tight junctions between components are typically fabricated from one or more materials having a predetermined stiffness (e.g., elastic modulus) suitable to accommodate conditions of a particular application. However, the inventors have observed that such conventional seals are effective only in a specific pressure range for which the seal was designed, thereby lacking operational flexibility.
For example, a seal fabricated for use in a high pressure application is typically fabricated from a comparatively stiff material, as compared to a seal fabricated for use in a low pressure application. However, the stiffer material lacks an ability to deform sufficiently to facilitate forming a seal at lower pressures while the softer material exhibits deformation that is too great to facilitate forming a seal at higher pressures.
Therefore, the inventors have provided an improved seal having a variable elastic modulus.
Embodiments of a seal having a variable elastic modulus are provided herein.
In one embodiment, a seal having a variable elastic modulus may include: a body fabricated from an elastomeric material; a channel formed within the body; a tube disposed within the channel, the tube comprising a plurality of interwoven fibers; and an inlet formed in an outer surface of the body, the inlet fluidly coupled to an inner volume of the tube.
In one embodiment, an o-ring having a variable elastic modulus may include: a substantially circular body fabricated from an elastomeric material; a channel formed within the body; a tube disposed within the channel, the tube comprising a plurality of interwoven fibers; and an inlet formed in an outer surface of the body, the inlet fluidly coupled to an inner volume of the tube.
In one embodiment, a packer element for a zonal isolation device or blowout preventer may include: a semicircular body fabricated from an elastomeric material, the body having a first flange and a second flange respectively coupled to a first end and a second end of the body, wherein the first flange and the second flange are configured to interface with one or more components of the zonal isolation device or blowout preventer; a channel formed within the body, the channel having a first end and a second end respectively disposed proximate the first end and the second end of the body; a tube disposed within the channel, the tube comprising a plurality of interwoven fibers; and an inlet formed in an outer surface of the body, the inlet fluidly coupled to an inner volume of the tube.
The foregoing and other features of embodiments of the present invention will be further understood with reference to the drawings and detailed description.
Embodiments of the present invention, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the invention depicted in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and are therefore not to be considered limiting in scope, for the invention may admit to other equally effective embodiments.
To facilitate understanding, identical reference numbers have been used, where possible, to designate identical elements that are common to the figures. The figures are not drawn to scale and may be simplified for clarity. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Embodiments of a seal having a variable elastic modulus are disclosed herein. The inventive seal advantageously provides a tube having a plurality of interwoven fibers disposed within a body of the seal that allows an elastic modulus of the seal to be varied as a pressure within the tube is changed. By varying the elastic modulus of the seal, the seal may be functional in a wider range of operating conditions (e.g., temperature and/or pressure) as compared to conventionally utilized seals, thereby providing a seal having improved flexibility with respect to a range of applications.
The body 102 may comprise any shape suitable to form a seal between components in a desired application and may be dependent on the size and/or shape of the components. For example, in one embodiment, the body 102 may be substantially ring shaped (e.g., in applications where the seal 100 may be utilized as an o-ring), having an inner diameter 110 and an outer diameter 108 such as shown in
The body 102 may be fabricated from any elastomeric material that is compatible with process conditions of a desired application. For example, in one embodiment, the body 102 may be fabricated from a polymer, such as a rubber compound, silicone or the like. In embodiments where the body 102 is fabricated from a rubber compound, the compound may be based on any suitable rubber compound, for example, such as a compound based on nitrile butadiene rubber, hydrogenated butadiene rubber, natural rubber, butyl rubber, fluorocarbon rubber, perfluorinated rubber, silicone rubber, polyurethane rubber, styrene butadiene rubber, butadiene rubber, polychloroprene rubber, epichlorohydrin rubber, silicone rubber, ethylenpropylene diene rubber, polyacrylate rubber, or the like. The rubber compound may be selected at least in part based on properties that may be suitable to accommodate a particular application. For example, the inventors have observed that butyl rubber may have a sufficiently low permeability to function as a barrier. In another example, nitrile butadiene rubber, hydrogenated butadiene rubber, fluorocarbon rubber, perfluorinated rubber, polychloroprene rubber and epichlorohydrin rubber may provide oil and/or chemical resistance. In another example, fluorocarbon rubber, perfluorinated rubber, silicone rubber and hydrogenated butadiene rubber may be beneficial in high temperature applications.
In one embodiment, an inlet 112 may be formed in an outer surface 114 of the body 102, extending at least partially through the body 102, such as shown in
The channel 104 may be disposed in any position within the body 102 suitable to facilitate varying the elastic modulus of the seal 100 throughout at least a portion of the seal 100. For example, in embodiments where the body 102 is substantially ring shaped, the channel 104 may also ring shaped and disposed such that the channel 104 is concentric with the body 102, such as shown in
The tube 106 is disposed within the channel 104 and generally comprises a plurality of interwoven fibers 116. The fibers of the plurality of interwoven fibers 116 may be fabricated from any substantially inelastic material. For example, in one embodiment, the fibers may be fabricated from a polymer based material, such as nylon, polyester, cotton, rayon or the like.
Referring to
The pressure within the inner volume 204 of the tube 106 may be increased or decreased via any manner suitable to increase or decrease the pressure to a desired magnitude in accordance with a particular application. For example, in one embodiment, the pressure may be varied via a provision or removal of a fluid, for example a non-compressible or hydraulic fluid (e.g., water, oils, alcohols, esters, silicones, or the like) to the inner volume 204 of the tube 106. As used herein, the term “non-compressible” means a fluid having a bulk modulus of about 100,000 psi or greater. However, it is to be noted that a compressible fluid with a comparatively lower bulk modulus (e.g., air, nitrogen, or the like) may also be utilized and may be dependent on the particular application. Alternatively, or in combination, in one embodiment, the pressure may be varied via an increase or decrease of pressure applied to a volume of the non-compressible or hydraulic fluid disposed within the inner volume 204 of the tube 106.
The stiffness of the tube 106 (and, therefore, the seal) may be increased to any stiffness suitable to accommodate a desired application. For example, in one embodiment, the elastic modulus of the tube 106 may be increased by up to 2 orders of magnitude, for example, from about 1 MPa to about 100 MPa.
In one embodiment, the tube 106 may comprise an inner tube 202 disposed within the inner volume 204 of the tube 106 and proximate an inner surface 206 of the tube 106. When present, the inner tube 202 may function to prevent leakage of the non-compressible or hydraulic fluid from the tube 106, for example, in embodiments where the tube 106 is porous. In addition, the inner tube 202 may prevent exposure of the plurality of fibers 116 to the non-compressible or hydraulic fluid disposed within the inner volume 204 of the tube 106, thereby preventing or reducing degradation of the plurality of fibers 116 that would otherwise be caused by exposure of the plurality of fibers 116 to the non-compressible or hydraulic fluid. The inner tube 202 may be fabricated from any elastic material that is compatible or non-reactive with the non-compressible or hydraulic fluid and may be dependent on a desired application. For example, in one embodiment, the inner tube 202 may be fabricated from a polymer, such as a rubber compound, silicone or the like.
The plurality of interwoven fibers 116 may be configured in any manner suitable to facilitate the increase or decrease in the elastic modulus of the seal as described above. For example, referring to
Although described above as having a circular shape, the body 102 and/or tube 106 may have any shape suitable to accommodate for a desired application. For example, in one embodiment, such as where the seal 100 is utilized as a packer element for a zonal isolation device or blow out preventer (BOP) (e.g., a fixed bore ram, annual packer, variable ram packer (Hydril), or the like), the body 102 and tube 106 may have a substantially semicircular shape, such as shown in
In one embodiment, a pressure controller 408 may be fluidly coupled to the inlet 112 to facilitate controlling the pressure within the tube 106 to vary the elastic modulus of the seal (e.g., as described above). The pressure controller 408 may comprise any components suitable to vary the pressure in such a manner. For example, in one embodiment, the pressure controller 408 may comprise a fluid source (e.g., the hydraulic or non-compressible fluid described above) configured to facilitate the provision or reduction of fluid pressure within the tube 106, as described above. Alternatively, or in combination, in one embodiment, the pressure controller 408 may comprise a mechanical actuator configured to apply pressure to the fluid disposed within the tube 106 to facilitate an increase of pressure within the tube 106. In one embodiment, a valve 410 may be fluidly coupled to the inlet 112 to selectively open or seal the inlet 112.
Referring to
In one embodiment, one or more membranes may be disposed in the through hole 510 and/or inlet 112 (first membrane 512 disposed in the through hole 510 and second membrane 514 disposed in the inlet 112 shown) and positioned such that a surface of the membrane is substantially perpendicular with a longitudinal axis of the inlet 112. When present, the one or more membranes facilitate a transfer of pressure from the high pressure side 516 to the inner volume 204 of the tube 106 while isolating a fluid disposed in each of the high pressure side 516 and the inner volume 204, thereby allowing different fluids and/or environments to be present in the inner volume 204 of the tube 106 and the high pressure side 516.
Thus, embodiments of a seal having a variable elastic modulus have been provided herein. In at least one embodiment, the inventive seal may advantageously be functional in a wider range of operating conditions (e.g., temperature and/or pressure) as compared to conventionally utilized seals, thereby providing a seal having improved flexibility with respect to a range of applications.
Ranges disclosed herein are inclusive and combinable (e.g., ranges of “an angle of about 50 degrees to about 60 degrees”, is inclusive of the endpoints and all intermediate values of the ranges of “about 50 degrees to about 60 degrees,” etc.). “Combination” is inclusive of blends, mixtures, alloys, reaction products, and the like. Furthermore, the terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. The modifier “about” used in connection with a quantity is inclusive of the state value and has the meaning dictated by context, (e.g., includes the degree of error associated with measurement of the particular quantity). The suffix “(s)” as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the colorant(s) includes one or more colorants). Reference throughout the specification to “one embodiment”, “another embodiment”, “an embodiment”, and so forth, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
