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Procedure Puzzler
Readers provide suggestions to feasible chemical processing scenarios. Test your abilities and provide suggestions here.
Early use of butterfly valves focused on water applications, but new designs and component materials have allowed them to be utilized in growing industrial fluid applications. Presently, butterfly valves can be discovered in almost every chemical plant handling a number of diverse fluids.
Butterfly valves range in size from 1 in to more than 200 in and most have a pressure capability of 150-psi to 740-psi cold working pressure. The general temperature rating for a resilient seated valve is 25 Degrees F to 300 Degrees F and 400 Degrees F to 450 Degrees F for a high-performance butterfly valve.
The butterfly valve may be used for on-off service or modulating service. Actuation is usually achieved either manually (handle, wrench, gear operator) or via an external power source to cycle the valve automatically.
Summarizing these are the three kinds of butterfly valves:
Resilient butterfly valve which has a flexible rubber seat. Working pressure 232 PSI
High performance butterfly valve which is usually double eccentric in style. Working pressure up to 725 PSI
1-4, the outer faces 108 of hubs 104 and 106 are spherically shaped, are disposed in concentric relation to spherical bottom walls of respective circular groove portions and compressingly engage the circular sections of the sealing ring throughout all positions of disc 100. The opposed, external circumferential surfaces 110 and 112 of body 102 extending between hubs 104 and 106, like semicircular portions 70 and 72 of disc 16 in FIGS. 1-4, are spherically shaped and sealingly engage corresponding semicircular sections of the sealing ring when disc 100 is in a closed position.
Extending from the opposite sides of body 102 are a plurality of laterally spaced vanes 114 which slidably and compressively engage the semicircular sections of the sealing ring at all times apart from when the valve is in a closed position. The spacings 116 between vanes 114 serve as fluid flow passages when disc 100 is in an open position. Therefore, the semicircular sections of the sealing ring are mechanically retained within the groove by the disc throughout all positions thereof during opening and closing of the valve.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to valves and to internal gasket seal liners for sealing valve discs in closed position to stop the flow of liquids. Much more particularly the invention relates to a rubber gasket for butterfly valves of the type commonly used in waterlines and pipelines, in which the gasket is precision-molded and vulcanized and then later bonded to the valve body to form a liquidtight circumferential seal within the valve body for the butterfly valve disc.
2. Description of the Prior Art
Butterfly valves generally have been created by casting a valve body, then machining the casting to shape, then shipping the body to a rubber plant where a rubber seal gasket is molded and vulcanized in a cavity of the valve body, and then returning the valve body with the gasket vulcanized therein to the valve plant for final assembly, storage and distribution. Fantastic expense is involved for shipping expenses of heavy valve bodies which might weigh hundreds of pounds; for rubber plant-vulcanizing and molded equipment; and for maintaining inventories of all sizes and types of valves.
Procedure Puzzler
Readers provide suggestions to feasible chemical processing scenarios. Test your abilities and provide suggestions here.
Early use of butterfly valves focused on water applications, but new designs and component materials have allowed them to be utilized in growing industrial fluid applications. Presently, butterfly valves can be discovered in almost every chemical plant handling a number of diverse fluids.
Butterfly valves range in size from 1 in to more than 200 in and most have a pressure capability of 150-psi to 740-psi cold working pressure. The general temperature rating for a resilient seated valve is 25 Degrees F to 300 Degrees F and 400 Degrees F to 450 Degrees F for a high-performance butterfly valve.
The butterfly valve may be used for on-off service or modulating service. Actuation is usually achieved either manually (handle, wrench, gear operator) or via an external power source to cycle the valve automatically.
Summarizing these are the three kinds of butterfly valves:
Resilient butterfly valve which has a flexible rubber seat. Working pressure 232 PSI
High performance butterfly valve which is usually double eccentric in style. Working pressure up to 725 PSI
1-4, the outer faces 108 of hubs 104 and 106 are spherically shaped, are disposed in concentric relation to spherical bottom walls of respective circular groove portions and compressingly engage the circular sections of the sealing ring throughout all positions of disc 100. The opposed, external circumferential surfaces 110 and 112 of body 102 extending between hubs 104 and 106, like semicircular portions 70 and 72 of disc 16 in FIGS. 1-4, are spherically shaped and sealingly engage corresponding semicircular sections of the sealing ring when disc 100 is in a closed position.
Extending from the opposite sides of body 102 are a plurality of laterally spaced vanes 114 which slidably and compressively engage the semicircular sections of the sealing ring at all times apart from when the valve is in a closed position. The spacings 116 between vanes 114 serve as fluid flow passages when disc 100 is in an open position. Therefore, the semicircular sections of the sealing ring are mechanically retained within the groove by the disc throughout all positions thereof during opening and closing of the valve.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to valves and to internal gasket seal liners for sealing valve discs in closed position to stop the flow of liquids. Much more particularly the invention relates to a rubber gasket for butterfly valves of the type commonly used in waterlines and pipelines, in which the gasket is precision-molded and vulcanized and then later bonded to the valve body to form a liquidtight circumferential seal within the valve body for the butterfly valve disc.
2. Description of the Prior Art
Butterfly valves generally have been created by casting a valve body, then machining the casting to shape, then shipping the body to a rubber plant where a rubber seal gasket is molded and vulcanized in a cavity of the valve body, and then returning the valve body with the gasket vulcanized therein to the valve plant for final assembly, storage and distribution. Fantastic expense is involved for shipping expenses of heavy valve bodies which might weigh hundreds of pounds; for rubber plant-vulcanizing and molded equipment; and for maintaining inventories of all sizes and types of valves.
