Abstract: The example methods and apparatus reduce and/or eliminate adverse effects of welding work pieces having dissimilar compositions. An example method includes depositing a first weld layer on a first end of a first work piece. The first work piece has a first content of a metallic element and the first weld layer has a second content of the metallic element higher than the first content. The example method includes depositing a second weld layer between the first weld layer and a second end of a second work piece to couple the first work piece to the second work piece. The second weld layer has a third content of the metallic element higher than the second content, and the second work piece has a fourth content of the metallic element higher than the first content.

Abstract: The example methods and apparatus reduce and/or eliminate adverse effects of welding work pieces having dissimilar compositions. An example method includes depositing a first weld layer on a first end of a first work piece. The first work piece has a first content of a metallic element and the first weld layer has a second content of the metallic element higher than the first content. The example method includes depositing a second weld layer between the first weld layer and a second end of a second work piece to couple the first work piece to the second work piece. The second weld layer has a third content of the metallic element higher than the second content, and the second work piece has a fourth content of the metallic element higher than the first content.

Abstract: The example methods and apparatus reduce and/or eliminate adverse effects of welding work pieces having dissimilar compositions. An example method includes depositing a first weld layer on a first end of a first work piece. The first work piece has a first content of a metallic element and the first weld layer has a second content of the metallic element higher than the first content. The example method includes depositing a second weld layer between the first weld layer and a second end of a second work piece to couple the first work piece to the second work piece. The second weld layer has a third content of the metallic element higher than the second content, and the second work piece has a fourth content of the metallic element higher than the first content.

Abstract: The example methods and apparatus reduce and/or eliminate adverse effects of welding work pieces having dissimilar compositions. An example method includes depositing a first weld layer on a first end of a first work piece. The first work piece has a first content of a metallic element and the first weld layer has a second content of the metallic element higher than the first content. The example method includes depositing a second weld layer between the first weld layer and a second end of a second work piece to couple the first work piece to the second work piece. The second weld layer has a third content of the metallic element higher than the second content, and the second work piece has a fourth content of the metallic element higher than the first content.

Abstract: A seal assembly for a fluid pressure control device includes a guide element having a sealing surface and a first guide surface. A throttling element assembly includes a throttling element positionable within a fluid flow path, the assembly defines a mating surface adapted to seal with the sealing surface, and a second guide surface sized to slidingly engage the first guide surface. A relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces to receive loose solid material, to thereby prevent disruption of the seal formed between the sealing surface and the mating surface.

Abstract: A control valve having a shiftable valve plug includes a valve body having an inlet, an outlet, a flow passage extending between the inlet and the outlet, and defining a longitudinal axis, a generally cylindrical valve cage disposed within the valve body and sized to receive the valve plug, with the valve cage including at least one aperture comprising at least a portion of the flow passage, a portion of the valve cage disposed adjacent a portion of the valve body at an interface. A seal having a C-shaped cross section is provided and is disposed at the interface between the valve cage and the valve body, and a retainer is disposed adjacent the interface and positioned to secure the seal against movement along the longitudinal axis.

Abstract: A control valve having a shiftable valve plug includes a valve body having an inlet, an outlet, a flow passage extending between the inlet and the outlet, and defining a longitudinal axis, a generally cylindrical valve cage disposed within the valve body and sized to receive the valve plug, with the valve cage including at least one aperture comprising at least a portion of the flow passage, a portion of the valve cage disposed adjacent a portion of the valve body at an interface. A seal having a C-shaped cross section is provided and is disposed at the interface between the valve cage and the valve body, and a retainer is disposed adjacent the interface and positioned to secure the seal against movement along the longitudinal axis.

Abstract: A seal assembly for a fluid pressure control device includes a guide element having a sealing surface and a first guide surface. A throttling element assembly includes a throttling element positionable within a fluid flow path, the assembly defines a mating surface adapted to seal with the sealing surface, and a second guide surface sized to slidingly engage the first guide surface. A relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces to receive loose solid material, to thereby prevent disruption of the seal formed between the sealing surface and the mating surface.

Abstract: A seal assembly for a fluid pressure control device includes a guide element having a scaling surface and a first guide surface. A throttling element assembly includes a throttling element positionable within a fluid flow path, the assembly defines a mating surface adapted to seal with the sealing surface, and a second guide surface sized to slidingly engage the first guide surface. A relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces to receive loose solid material, to thereby prevent disruption of the seal formed between the sealing surface and the mating surface.

Abstract: A control valve having a shiftable valve plug includes a valve body having an inlet, an outlet, a flow passage extending between the inlet and the outlet, and defining a longitudinal axis, a generally cylindrical valve cage disposed within the valve body and sized to receive the valve plug, with the valve cage including at least one aperture comprising at least a portion of the flow passage, a portion of the valve cage disposed adjacent a portion of the valve body at an interface. A seal having a C-shaped cross section is provided and is disposed at the interface between the valve cage and the valve body, and a retainer is disposed adjacent the interface and positioned to secure the seal against movement along the longitudinal axis.

Abstract: Split packing followers for use with valves are disclosed. A disclosed packing follower includes a first member having a first portion of a flange and a first portion of a curved wall extending substantially perpendiculary from the first portion of the flange to define a first portion of a cylindrical member. The disclosed packing follower further includes a second member separable from the first member. The second member include a second portion of the flange and a second portion of a curved wall extending substantially perpendiculary from the second portion of the flange to define a second portion of the cylindrical member. The first and second member include complementary interlocking structures that are configured to mechanically couple the first and second members to form the packing follower.

Abstract: A clock circuit includes an oscillator for generating a reference frequency signal, and a spread spectrum clock generator cooperating with the oscillator for generating a spread spectrum clock output signal having a fundamental frequency and reduced amplitude EMI spectral components at harmonics of the fundamental frequency. The spread spectrum clock generator preferably includes a clock pulse generator for generating a series of clock pulses, and a spread spectrum modulator for frequency modulating the clock pulse generator to broaden and flatten amplitudes of EMI spectral components which would otherwise be produced by the clock pulse generator. The spread spectrum modulator frequency modulates the clock pulses with specific profiles of frequency deviation versus the period of the profile. Electronic devices including the spread spectrum clock circuit and associated method are also disclosed.

Abstract: A wafer handling technique allows for picking up a wafer from its front side. One or more vacuum ports pull the periphery of the wafer into contact with a ledge raised from a broad surface, providing a friction force that prevents lateral movement of the wafer. A port in the broad surface of the handler flows pressurized gas onto the wafer, thereby preventing contact between the handler and the interior of the wafer. The handler may be sized to be relatively thin, and to cover less than half of the surface of the wafer, thereby allowing for readily loading wafers back-to-back in a furnace boat.