초록 ▼

In a valve structure, a valve plug apparatus to provide a leak-tight valve shut-off, is disclosed. The valve structure includes a valve body provided with an inlet passage, an outlet passage and an internal web portion intermediate the inlet and outlet passages. A closeable passage-forming means is

In a valve structure, a valve plug apparatus to provide a leak-tight valve shut-off, is disclosed. The valve structure includes a valve body provided with an inlet passage, an outlet passage and an internal web portion intermediate the inlet and outlet passages. A closeable passage-forming means is arranged in the web portion and a two-member valve plug is mounted on a valve stem for controlled axial movement within the web portion and operable to close said closeable fluid passage-forming means to shut the valve. In accordance with the invention, the two-member valve plug comprises a lower plug member and an upper plug member which are in a generally axially spaced relation on the valve stem. Packing means is held in a snug-fitting condition between the lower and upper plug members by an axially resilient member which acts between one end of the valve stem and the valve plug to urge the lower and upper plug members together. When the two-member valve plug closes the closeable fluid passage-forming means, a force is transmitted by the valve stem directly through the upper plug member to the packing means to form a leak-tight seal for the valve plug. The stem force is also transmitted through the packing means and lower plug member to generate a seating force between the valve plug and closeable fluid passage-forming for a tight valve shut-off.

대표청구항 ▼

In a valve structure including a valve body having an inlet and outlet passage and an internal web portion intermediate the inlet and outlet passages, means arranged in said web portion forming a closeable flow path between said inlet and outlet passages, and a valve stem associated with said web po

In a valve structure including a valve body having an inlet and outlet passage and an internal web portion intermediate the inlet and outlet passages, means arranged in said web portion forming a closeable flow path between said inlet and outlet passages, and a valve stem associated with said web portion, a valve plug apparatus to provide a leak-tight valve shut-off, characterized by (a) a two-member valve plug comprising a lower plug member and an upper plug member, (b) said lower and upper plug members being mounted in a generally axially spaced relation on said valve stem, whereby said two-member valve plug is controllable by the valve stem to close said closeable flow path means, (c) packing means arranged between and held by said lower and upper plug members, (d) at least one of said plug members being slidably associated with said valve stem whereby the relative axial orientation of the plug members is variable to vary the holding force on said packing means, and (e) means associated with said two-member valve plug operative upon said lower and upper plug members and said packing means whereby the packing means is maintained in a snug fit between the lower and upper plug members for all axial positions of said valve stem, (f) said valve stem being in a direct, force-transmitting relation with said upper plug member and said upper plug member only when said valve and valve stem are in fully closed positions for all axial positions of the valve stem after the valve is in said fully closed position whereby the force produced by the valve stem when the valve and stem are in said fully closed positions will be transmitted solely and directly through said upper plug member to urge the two plug members together with a force proportional to the closing force applied by said stem thereby increasing the holding force on the packing means in proportion to the closing force applied by said stem for all axial positions of the valve stem after the valve is in said fully closed position to form a leak-tight seal around the valve plug and through the packing means to the lower plug member to provide a tight valve shut-off.