Butterfly valve having an improved stem seal

Claim 2

In a valve of the type including a valve body having a resilient lining having at least one opening for receiving pivot means of a valve member positioned within the lining and rotatable between open and closed positions, the improvement of a stem seal for said valve comprising: sealing means carried by a pivotal end of said valve member and extending through said opening in said lining, said sealing means extending circumferentially around said pivotal end and projecting radially therefrom, and a sealing ring associated with said sealing means on said pivotal end of said valve member, said sealing ring having a tubular portion the inner surface of which is adapted to engage the radially projecting portions of said sealing means, said tubular portion of said sealing ring extending through said opening in said lining and having an outer end flange which extends radially over the portion of said lining surrounding said opening therein, whereby said lining is permitted to move linearly under said flange when distorted by said valve member being moved into the closed position while maintaining a seal around the axis of said valve member.

Claim 3

In a valve of the type according to claim 1 wherein said valve member is encapsulated in a plastic resin and said sealing means is integral with said pivotal end of said plastic resin encapsulated valve member.

Claim 4

In a valve of the type according to claim 1 wherein both said sealing means and said sealing ring are constructed from a fluorocarbon resin.

Claim 5

In a butterfly valve of the type including a valve body having a cylindrical bore with diametrically opposed openings for receiving pivot means, the improvement comprising: a resilient lining means for the cylindrical bore of the valve body, said lining having a tubular portion adapted to be positioned in the cylindrical bore of the valve body, said tubular portion of said lining having diametrically opposed openings adapted for alignment with the openings in the valve body and opposed flat surfaces each having said respective openings centered therein, a substantially rigid butterfly disc within said tubular portion of said lining on the diameter passing through said aligned openings and movable between open and closed positions, said disc having a diameter related to that of said tubular portion of said valve lining to provide an interference fit therewith when said disc is in the closed position, said butterfly disc having diametrically opposed pivotal ends aligned with said openings in said lining, each of said pivotal ends having sealing means extending circumferentially around said pivotal ends and projecting radially therefrom, and a pair of sealing rings, one ring being associated with each of said sealing means on said pivotal ends of said butterfly disc, each of said sealing rings having a tubular portion the inner surface of which is adapted to engage said radially extending sealing means, said tubuLar portion of said sealing rings extending through said diametrically opposed openings in said lining and having an outer end flange which extends radially over the outer one of said flat surfaces of said lining surrounding said diametrically opposed openings, whereby said lining is permitted to move linearly under said flange when distorted by said butterfly disc being moved into the closed position while maintaining a seal around the axis of said butterfly disc.

Claim 6

In a butterfly valve of the type including a valve body having a cylindrical bore with diametrically opposed openings for receiving pivot means, the improvement comprising: a resilient lining means for the cylindrical bore of the valve body, said lining having a tubular portion adapted to be positioned in the cylindrical bore of the valve body, said tubular portion of said lining having diametrically opposed openings adapted for alignment with the openings in the valve body and opposed flat surfaces each having said respective openings centered therein, a substantially rigid butterfly disc within said tubular portion of said lining on the diameter passing through said aligned openings and movable between open and closed positions, said disc having a diameter related to that of said tubular portion of said valve lining to provide an interference fit therewith when said disc is in the closed position, said butterfly disc having diametrically opposed pivotal ends aligned with said openings in said lining, each of said pivotal ends having sealing means extending circumferentially around said pivotal ends and projecting radially therefrom, and a pair of sealing rings, one ring being associated with each of said sealing means on said pivotal ends of said butterfly disc, each of said sealing rings having a tubular portion the inner surface of which is adapted to engage said radially extending sealing means, said tubuLar portion of said sealing rings extending through said diametrically opposed openings in said lining and having an outer end flange which extends radially over the outer one of said flat surfaces of said lining surrounding said diametrically opposed openings, whereby said lining is permitted to move linearly under said flange when distorted by said butterfly disc being moved into the closed position while maintaining a seal around the axis of said butterfly disc.

Claim 7

In a butterfly valve according to claim 4 wherein said resilient lining means includes resilient backup means positioned between the cylindrical portion of the valve body and said tubular portion of said lining.

Claim 8

In a butterfly valve according to claim 4 including rigid backup ring means positioned in the cylindrical bore and supporting said resilient backup means with respect to said tubular portion of said lining.

Claim 9

In a butterfly valve according to claim 6 wherein said rigid backup ring means includes structure for preventing axial displacement of said resilient backup means with respect to said tubular portion of said lining.

Claim 10

In a butterfly valve according to claim 6 wherein said tubular portion of said lining is provided with end flanges extending radially outward therefrom, the outside diameter of said end flanges being substantially the same as the outside diameter of said rigid backup ring means.

Claim 11

In a butterfly valve according to claim 6 wherein said rigid backup ring means has diametrically opposed openings adapted for alignment with the openings in the valve body and said lining, and pressure pad means surrounding said openings in said rigid backup ring means and positioned between said rigid backup ring means and said resilient backup ring means.

Claim 12

In a butterfly valve of the type including a valve body having a cylindrical bore within diametrically opposed openings for receiving pivot means, the improvement comprising: a plastic resin lining for the cylindrical bore of the valve body, said lining having a tubular portion adapted to be positioned in the cylindrical bore of the valve body, said tubular portion of said lining having diametrically opposed openings adapted for alignment with the openings in the valve body for receiving pivot means, resilient backup means positioned between said tubular portion of said lining and the cylindrical bore of the valve body, a substantially rigid plastic resin encapsulated butterfly disc within said tubular portion of said plastic resin lining on the diameter passing through said aligned openings and movable between open and closed positions, said disc having a diameter related to that of said tubular portion of said valve lining to provide an interference fit therewith when said disc is in the closed position, said butterfly disc having diametrically opposed pivotal ends aligned with said openings in said lining, each of said pivotal ends having sealing means extending circumferentially around said pivotal ends and projecting radially therefrom, and a pair of sealing rings, one ring being associated with each of said sealing means on said pivotal ends of said butterfly disc, each of said sealing rings having a tubular portion the inner surface of which is adapted to engage said radially extending portions of said sealing means, said tubular portion of sid sealing rings extending through said diametrically opposed openings in said lining and having an end flange which extends radially between said lining surrounding said diametrically opposed openings and said resilient backup means, whereby said lining is permitted to move linearly upon said flange when distorted by said butterfly disc being moved into the closed position while maintaining a seal around the axis of said butterfly disc.

Claim 13

In a butterfly valve of the type including a valve body having a cylindrical bore within diametrically opposed openings for receiving pivot means, the improvement comprising: a plastic resin lining for the cylindrical bore of the valve body, said lining having a tubular portion adapted to be positioned in the cylindrical bore of the valve body, said tubular portion of said lining having diametrically opposed openings adapted for alignment with the openings in the valve body for receiving pivot means, resilient backup means positioned between said tubular portion of said lining and the cylindrical bore of the valve body, a substantially rigid plastic resin encapsulated butterfly disc within said tubular portion of said plastic resin lining on the diameter passing through said aligned openings and movable between open and closed positions, said disc having a diameter related to that of said tubular portion of said valve lining to provide an interference fit therewith when said disc is in the closed position, said butterfly disc having diametrically opposed pivotal ends aligned with said openings in said lining, each of said pivotal ends having sealing means extending circumferentially around said pivotal ends and projecting radially therefrom, and a pair of sealing rings, one ring being associated with each of said sealing means on said pivotal ends of said butterfly disc, each of said sealing rings having a tubular portion the inner surface of which is adapted to engage said radially extending portions of said sealing means, said tubular portion of sid sealing rings extending through said diametrically opposed openings in said lining and having an end flange which extends radially between said lining surrounding said diametrically opposed openings and said resilient backup means, whereby said lining is permitted to move linearly upon said flange when distorted by said butterfly disc being moved into the closed position while maintaining a seal around the axis of said butterfly disc.

Claim 14

In a valve of the type including a valve body having a resilient lining having at least one opening for receiving pivotal means of a valve member positioned within the lining and rotatable between open and closed positions, an improved stem seal for said valve comprising: first sealing means carried by a pivotal end of the valve member and extending through the opening in the lining, said first sealing means extending circumferentially around the pivotal end, and second sealing means surrounding said first sealing means, said second sealing means comprising a sealing ring having a tubular portion the inner surface of which is disposed in face to face relation with the portion of said first sealing means which extends through the opening in the lining, said tubular portion of said sealing ring extending through the opening in the lining and having an outer end flange which extends radially over the portion of the lining surrounding the opening therein, and structure extending circumferentially around one of said sealing means and projecting radially therefrom for engagement with the adjacent face of said other sealing means, whereby the lining is permitted to move linearly under said flange when distorted by the valve member being moved into the closed position while maintaining a seal around the axis of the valve member.

Claim 15

In a valve of the type including a valve body having a resilient lining having at least one opening for receiving pivotal means of a valve member positioned within the lining and rotatable between open and closed positions, an improved stem seal for said valve comprising: first sealing means carried by a pivotal end of the valve member and extending through the opening in the lining, said first sealing means extending circumferentially around the pivotal end, and second sealing means surrounding said first sealing means, said second sealing means comprising a sealing ring having a tubular portion the inner surface of which is disposed in face to face relation with the portion of said first sealing means which extends through the opening in the lining, said tubular portion of said sealing ring extending through the opening in the lining and having an outer end flange which extends radially over the portion of the lining surrounding the opening therein, and structure extending circumferentially around one of said sealing means and projecting radially therefrom for engagement with the adjacent face of said other sealing means, whereby the lining is permitted to move linearly under said flange when distorted by the valve member being moved into the closed position while maintaining a seal around the axis of the valve member.

Claim 16

A butterfly valve having an improved stem seal comprising: a valve body having a cylindrical bore with diametrically opposed openings for receiving pivot means, a substantially rigid plastic resin lining for the cylindrical bore of the valve body, said lining having a tubular portion adapted to be positioned in the cylindrical bore of said valve body and having end flanges extending radially outward from said tubular portion, the outside diameter of said end flanges being substantially the same as the inside diameter of the said cylindrical bore of the valve body, rigid backup ring means positioned in said cylindrical bore between said valve body and said tubular portion of said lining, said tubular portion of said lining and said rigid backup means having diametrically opposed openings adapted for alignment with the openings in the valve body for receiving pivot means, resilient backup means positioned between said rigid backup means and said tubular portion of said lining, said end flanges of said lining extending radially over the edges of both of said backup means, a substantially rigid plastic resin encapsulated butterfly disc within said plastic resin lining on the diameter passing through said aligned openings and movable between open and closed positions, said disc having a diameter related to that of said tubular portion of said valve lining to provide an interference fit therewith when said disc is in the closed position, said butterfly disc having diametrically opposed pivotal ends aligned with said openings in said lining, each of said pivotal ends having sealing means extending circumferentially around said pivotal ends and projecting radially therefrom, and a pair of sealing rings, one ring being associated with each of said sealing means on said pivotal ends of said butterfly disc, each of said sealing rings having a tubular portion the inner surface of which is adapted to engage said radially extending portions of said sealing means, said tubular portion of said sealing rings extending through said diametrically opposed openings in said lining and having an end flange which extends radially between said lining surrounding said diametrically opposed openings and said resilient backup means, whereby said lining is permitted to move linearly under said flange when distorted by the butterfly disc being moved into the closed position while maintaining a seal around the axis of said butterfly disc.

Claim 17

A butterfly valve having an improved stem seal comprising: a valve body having a cylindrical bore with diametrically opposed openings for receiving pivot means, a substantially rigid plastic resin lining for the cylindrical bore of the valve body, said lining having a tubular portion adapted to be positioned in the cylindrical bore of said valve body and having end flanges extending radially outward from said tubular portion, the outside diameter of said end flanges being substantially the same as the inside diameter of the said cylindrical bore of the valve body, rigid backup ring means positioned in said cylindrical bore between said valve body and said tubular portion of said lining, said tubular portion of said lining and said rigid backup means having diametrically opposed openings adapted for alignment with the openings in the valve body for receiving pivot means, resilient backup means positioned between said rigid backup means and said tubular portion of said lining, said end flanges of said lining extending radially over the edges of both of said backup means, a substantially rigid plastic resin encapsulated butterfly disc within said plastic resin lining on the diameter passing through said aligned openings and movable between open and closed positions, said disc having a diameter related to that of said tubular portion of said valve lining to provide an interference fit therewith when said disc is in the closed position, said butterfly disc having diametrically opposed pivotal ends aligned with said openings in said lining, each of said pivotal ends having sealing means extending circumferentially around said pivotal ends and projecting radially therefrom, and a pair of sealing rings, one ring being associated with each of said sealing means on said pivotal ends of said butterfly disc, each of said sealing rings having a tubular portion the inner surface of which is adapted to engage said radially extending portions of said sealing means, said tubular portion of said sealing rings extending through said diametrically opposed openings in said lining and having an end flange which extends radially between said lining surrounding said diametrically opposed openings and said resilient backup means, whereby said lining is permitted to move linearly under said flange when distorted by the butterfly disc being moved into the closed position while maintaining a seal around the axis of said butterfly disc.