Expanding dual disc gate valve

A method for making a dual disc gate valve, comprising:

• providing a valve body defining a flow path therethrough;
• mounting a valve stem for axial movement in line with an axis of said valve stem and transversely with respect to said flow path;
• slidingly connecting a first disc with respect to said valve stem on a first side of said valve stem utilizing at least one wedge;
• providing a sliding interconnection between said first disc and said at least one wedge, said sliding interconnection being at a first angle with respect to said axis of said valve stem, wherein said sliding interconnection comprises at least one first slot at said first angle whereby movement of said at least one wedge away from said flow path urges said first disc to a contracted position;
• slidingly connecting a second disc with respect to said valve stem on a second side of said valve stem utilizing said at least one wedge, said second disc being slidable at a second angle with respect to said axis of said valve stem;
• providing that said valve stem is operable for moving said first disc and said second disc into and out of said flow path to an open position and a closed position of said dual disc gate valve;
• mounting a first sealing assembly on a first side of said flow path with respect to said valve stem;
• mounting a second sealing assembly on a second side of said flow path with respect to said valve stem;
• mounting at least one spring to apply a force to said first disc and said second disc;
• providing at least one stop surface whereby when said first disc and said second disc are engaged with said at least one stop surface then said first disc and said second disc are moveable to an expanded position so that said first disc engages with said first sealing assembly and said second disc engages with said second sealing assembly, and whereby said first disc and said second disc are moveable to said contracted position to disengage said first disc from said first sealing assembly and said second disc from said second sealing assembly;
• and
• providing said first sealing assembly with a resilient seat ring positioned within a groove, providing that when said valve is in said open position said resilient seat ring has a concave back that extends away from said groove, and providing that when said valve is in said closed position said concave back is compressed to engage said groove.

A dual disc gate valve connectable to a line, comprising:

• a valve body with a flow path therethrough;
• a valve cover mounted to said valve body that covers a valve cover opening leading to said flow path;
• a first sealing assembly mounted around a first side of said flow path and a second sealing assembly mounted around a second side of said flow path;
• a valve stem moveable transversely with respect to said flow path, said valve stem being mounted for axial movement in line with an axis of said valve stem;
• a first disc and a second disc mounted to be moveable in a retracted position into said flow path, said first disc and said second disc each being mounted to be wedgingly moveable in an angled direction with respect to said axis of said valve stem to an expanded position when positioned in said flow path;
• a stop surface positioned to engage said first disc and said second disc as said valve stem is moved towards said flow path;
• at least one spring positioned to apply a force to said first disc and said second disc wherein said at least one spring is positioned to urge said first disc and said second disc in a direction toward said stop surface, said at least one spring being mounted at an angle with respect to said stem axis;
• a first seal mounted in said first sealing assembly which is positioned to engage with said first disc when said first disc is in said expanded position and is offset from said first disc when said first disc is in said retracted position;
• a second seal mounted in said second sealing assembly which is positioned to engage with said second disc when said second disc is in said expanded position and is offset from said second disc when said second disc is in said retracted position;
• said first seal and said second seal being mounted so as to be removable through valve cover opening whereby said first seal and said second seal are in-line replaceable.

A dual disc gate valve, comprising:

• a valve body with a flow path therethrough;
• a first sealing assembly mounted around a first side of said flow path and a second sealing assembly mounted around a second side of said flow path;
• a first disc and a second disc mounted to be moveable in a retracted position into said flow path, said first disc and said second disc being mounted to be moveable to an expanded position when positioned in said flow path whereby said dual disc gate valve is in a closed position;
• a first seal for said first sealing assembly which is positioned to engage with said first disc when said first disc is in said expanded position and is offset from said first disc when said first disc is in said retracted position, said first seal comprising a first metal tongue and a first metal receptacle, said first metal tongue comprising a first metal tongue end larger than a first metal receptacle base, first angled sides for said first metal tongue and said first metal receptacle whereby in said closed position said first angled sides are wedgingly engaged to provide a metal-to-metal seal;
• and
• a second seal for said second sealing assembly which is positioned to engage with said second disc when said second disc is in said expanded position and is offset from said second disc when said second disc is in said retracted position, said second seal comprising a second metal tongue and a second metal receptacle, said second metal tongue comprising a second metal tongue end larger than a second metal receptacle base, second angled sides for said second metal tongue and said second metal receptacle whereby in said closed position said angled sides are wedgingly engaged to provide a metal-to-metal seal.

A dual disc gate valve, comprising:

• a valve body with a flow path therethrough;
• a first sealing assembly mounted around a first side of said flow path and a second sealing assembly mounted around a second side of said flow path;
• a first disc and a second disc mounted to be moveable in a retracted position into said flow path, said first disc and said second disc being mounted to be moveable to an expanded position when positioned in said flow path whereby said dual disc gate valve is in a closed position;
• a first seal for said first sealing assembly which is positioned to engage with said first disc when said first disc is in said expanded position and is offset from said first disc when said first disc is in said retracted position, said first seal comprising a first resilient seat ring positioned within a first groove, whereby when said first and second disc are in said retracted position, then said first resilient seat ring has a first concave back that extends away from a first bottom of said first groove, and when said valve is in said closed position then said first concave back is compressed to engage said first bottom of said first groove;
• and
• a second seal for said second sealing assembly which is positioned to engage with said second disc when said second disc is in said expanded position and offset from said second disc when said second disc is in said retracted position, said second seal comprising a second resilient seat ring positioned within a second groove, whereby when said first and second disc are in said retracted position, then said second resilient seat ring has a second concave back that extends away from a second bottom of said second groove, and when said valve is in said closed position then said second concave back is compressed to engage said second bottom of said second groove.

A dual disc gate valve, comprising:

• a valve body with a flow path therethrough;
• a first sealing assembly mounted around a first side of said flow path and a second sealing assembly mounted around a second side of said flow path;
• a first disc and a second disc mounted to a valve stem to be moveable in a retracted position into said flow path, said first disc and said second disc being mounted to be moveable with respect to at least one wedge carried by said valve stem to an expanded position when positioned in said flow path whereby said dual disc gate valve is in a closed position;
• a sliding interconnection between said first disc and said at least one wedge wherein said sliding interconnection comprises at least one slot at an angle with respect to said valve stem, whereby movement of said at least one wedge away from said flow path moves urges said first disc to move along said angle to said retracted position;
• a first seal for said first sealing assembly which is positioned to engage with said first disc when said first disc is in said expanded position and is offset from said first disc when said first disc is in said retracted position;
• a second seal for said second sealing assembly which is positioned to engage with said second disc when said second disc is in said expanded position and is offset from said second disc when said second disc is in said retracted position;
• and
• a bottoming structure located within said valve body for accumulating debris from within said valve body to prevent damage to said first and second discs, said bottoming structure comprising a shoulder adjacent a recessed basin, said bottoming structure further comprising a drain for removing said debris from said valve body, wherein said shoulder is slotted for allowing particles and/or debris to be forced through said shoulder by said first and second discs.