Abstract: A valve arrangement (10) for reducing the instability of fluid flow in a compressible flow governor valve includes a cutoff plug (12) with a lateral concave surface (14) and an end portion (16) having a substantially circular cross section, and a seat (30) with a convex surface (32). The lateral concave surface (14) and the end portion (16) of the cutoff plug (12) define an abrupt cutoff corner (18). The radius (re) of the end portion (16) of the cutoff plug (12) is less than the radius (Rs) of the seat (30). The radius of curvature (R) of the seat (30) is less than the radius of curvature (rq) of the lateral concave surface (14) of the cutoff plug (12). The configuration of the cutoff plug (12) and seat (30) enhances the annular flow pattern beneath the cutoff plug (12) at all lift positions thus reducing flow instability.

Abstract: A method of brazing stainless steel components to form a complex shape such as an impeller. The method includes the steps of providing the stainless steel components shaped and formed from a selected stainless steel alloy; providing a brazing alloy having a selected composition and compatibility with stainless steel; heating the stainless steel components and brazing alloy for a controlled time to a liquidus temperature to effect brazing; cooling the stainless steel components and brazing alloy to a quench temperature substantially lower than the liquidus temperature of the brazing alloy to provide a tensile strength of greater than about 20 Ksi in the brazing alloy; and quenching the assembly from the quench temperature to a temperature of less than about 400° F. in a given time to provide a brazed assembly free of distortion and cracks with desired mechanical properties in the stainless steel components by virtue of the thermal treatment.

Abstract: A method of brazing stainless steel components to form a complex shape such as an impeller. The method includes the steps of providing the stainless steel components shaped and formed from a selected stainless steel alloy; providing a brazing alloy having a selected composition and compatibility with stainless steel; heating the stainless steel components and brazing alloy for a controlled time to a liquidus temperature to effect brazing; cooling the stainless steel components and brazing alloy to a quench temperature substantially lower than the liquidus temperature of the brazing alloy to provide a tensile strength of greater than about 20 Ksi in the brazing alloy; and quenching the assembly from the quench temperature to a temperature of less than about 400° F. in a given time to provide a brazed assembly free of distortion and cracks with desired mechanical properties in the stainless steel components by virtue of the thermal treatment.

Abstract: A weld filler metal alloy composition and a method for welding stainless steel components into a final assembly includes the steps of: austenitizing the stainless steel components to be welded at a temperature of 1800° F.-2000° F.; applying, using conventional arc welding techniques a solid wire of the filler metal alloy comprising in % by weight: up to 0.02% carbon; up to 0.8% manganese; up to 0.02% phosphorus; up to 0.015% sulfur; up to 0.6% silicon; 4.5-5.5% nickel; 0.4-0.7% molybdenum; 10-12.5% chromium; up to 0.1% copper; balance essentially iron and incidental impurities; and tempering the welded assembly welded at a temperature of 930° F.-1300° F. A second tempering step conducted at a temperature of 1095° F.-1145° F. may follow. The welding method can be used to make compressor impellers (6). The compressor impeller components comprise 13Cr-4Ni stainless steel.

Abstract: The present invention provides a method of forming an abradable seal between rotating and non-rotating components of a machine. A sheet of abradable material is formed and then cut to a desired shape to form an abradable sheet piece. An adhesive composition is applied to at least a portion of a substrate surface and the sheet piece is contacted with the adhesive composition to adhesively bond the sheet piece to the substrate to form the abradable seal. An abradable seal is also provided having an adhesive composition deposited over at least a portion of a substrate surface with an abradable sheet piece bonded to the substrate by the adhesive composition.

Abstract: A multi-stage centrifugal compressor with an integral high-speed motor for compressing air has a variable speed permanent magnet motor having electronically commutated stator coils surrounding a rotor carrying permanent magnets, wherein there is a gap between the coils and the rotor. The rotor has a magnetic steel rotor shaft rotatably supported at each end by pressurized oil lubricated hydrodynamic bearings. The stator coils have a plurality of stator wires extending longitudinally along the stator and continuing around the ends of the stator to define end turns. The compressor also has a plurality of compressor impellers mounted to turn with the rotor shaft and cooler for cooling the bearings, rotor and stator coils comprising a pump for introducing cooled oil into the bearings, said bearing configured so that oil exiting from the bearings splashes over the supported ends of the shaft and splashes over the end turns of the stator coils.

Abstract: A casing design for rotating machinery that includes two semi-cylindrical shaped shell sections. Each of the sections includes a machined flange adapted to receive fasteners. The two sections are attached together through fasteners passing through the machined flanges.

Abstract: A reversible nozzle (10), removably attached to a fluid emitting base, such as a half turbine casing (22). The reversible nozzle (10) has a nozzle body (16) and a nozzle tube (12), with the nozzle body (16) preferably forming a plurality of fastener receiving slots (18, 18a). The nozzle tube (12) is angled with respect to the nozzle body (16). An installed reversible nozzle (10) is reversed by removing fasteners (34) connecting the nozzle body (16) to the fluid emitting base (22), rotating the nozzle body (16) about a normal nozzle body axis X, and resecuring the reversible nozzle (10) to the fluid emitting base (22) with fasteners (34). To aid in the alignment of the reversible nozzle (10), one fastener receiving slot (18a) is preferably elongated.

Abstract: A compressor blade vibration reduction mechanism for a high-speed radial impeller for minimizing fatigue failures from various excitation sources. The vibration reduction mechanism includes a plurality of loose-fitting lashing pins coupling each impeller blade to an adjacent impeller blade. Each lashing pin extends through a first aperture in a blade located adjacent to the blade tip and through a second aperture of an adjacent blade. The second aperture of each blade is located a greater distance from the leading edge of the blade than the first aperture. The second aperture is located in an area of the blade having lower vibration during operation than the blade location where the first aperture is located.

Abstract: A method of arc welding to build the thickness of a high sulfur, low alloy steel workpiece comprises the steps of preparing the surface of the high sulfur, low alloy workpiece; applying a layer of metal over the prepared surface using a low energy arc; and applying additional layers of metal using a high energy welding arc.

Abstract: A method for preventing one-cell rotating stall initiated by a bladed disc having a plurality of blades including the steps of identifying a one-cell stall condition and modifying one or more blades to force the bladed disc into at least a two-cell stall pattern. This can be accomplished by modifying the spacing between the blades to force the bladed disc into at least a two-cell stall pattern. Alternatively, at least one of the blades can be geometrically modified so as to force the bladed disc into at least a two-cell stall pattern.

Abstract: A method and apparatus for regulating the operation of a compressor system including a compressor moving a gas from an intake conduit through a discharge conduit to a gas storage reservoir are disclosed. In accordance with the method, an unload valve in an unload conduit connected to the discharge conduit is initially fully closed and an inlet valve in the intake conduit is initially fully opened. Then the inlet valve is closed by an amount necessary to maintain the discharge pressure at a design pressure level and at a gas flow rate between the design flow level and a minimum flow level. When the gas flow rate drops below the minimum flow level, the inlet valve is maintained in its last position and the unload valve is opened by an amount necessary to maintain the discharge pressure below a first pressure level set higher than the design pressure level.

Abstract: A method and apparatus for regulating the operation of a compressor system including a compressor moving a gas from an intake conduit through a discharge conduit to a gas storage reservoir are disclosed. In accordance with the method, an unload valve in an unload conduit connected to the discharge conduit is initially fully closed and an inlet valve in the intake conduit is initially fully opened. Then the inlet valve is closed by an amount necessary to maintain the discharge pressure at a design pressure level and at a gas flow rate between the design flow level and a minimum flow level. When the gas flow rate drops below the minimum flow level, the inlet valve is maintained in its last position and the unload valve is opened by an amount necessary to maintain the discharge pressure below a first pressure level set higher than the design pressure level.

Abstract: Apparatus for separating a gas from a liquid includes a degassing tank for receiving a mixture of the gas and liquid. The tank permits the gas to separate from the mixture and rise to the top of the tank and permits the liquid to separate from the mixture and settle to the bottom of the tank. The apparatus includes a vacuum regulator for withdrawing the separated gas from the degassing tank, a level detector for measuring the level of fluid in the degassing tank and a controller responsive to the level detector for controlling the vacuum regulator and reducing the gas flow therefrom as the fluid level in the degassing tank increases.

Abstract: A power recovery expander for use with a motive fluid of hot gas with entrained particulates is disclosed. Means for removal of entrained particulates and for cooling portions of the turbomachine are provided. Additionally, cooling fluid is directed to a separate cooling chamber, said cooling fluid being used to draw additional particulate matters from the motive fluid.

Abstract: A flexible damped bearing assembly for securing a rotating shaft maintained within a bearing is disclosed. An annular damper formed from a resilient material includes an axial bore for receiving the bearing and shaft. The damper is additionally slotted to define damper arms extending outwardly therefrom. Damper pads are used in conjunction with the damper arms to define pivot points about which the damper arms are displaced on the application of force to the damper. A damping fluid is provided between the slots and the exterior surface of the damper and a retainer structure such that numerous damping locations are provided. The damper arms are further defined to provide a spring force which may be tuned as required. This combination provides a compact bearing assembly capable of supporting a shaft while damping vibratory oscillations.

Abstract: A shaft seal assembly having an annular member affixed to the shaft for rotation therewith, a sleeve encompassing the shaft and being biased axially towards the annular member and a free floating sealing ring interposed between the annular member and the sleeve to prevent pressurized working substance form leaking about the shaft is disclosed. The sealing ring includes internal flow passageways which act to reduce the pressure of lubricant flowing therethrough to both effectively cool the free floating ring and to reduce the pressure of the lubricant obviating the necessity of a separate breakdown bushing.

Abstract: A tilt pad bearing assembly for use in supporting a rotating shaft is disclosed. The bearing assembly includes lubricant means for effectively cooling separate individual bearing pads, and separate cooling channels for selectively cooling a portion of the bearing pad. The bearing pads each have a specific end treatment to act in combination to provide an anti-spragging effect. Additionally by selectively cooling a portion of the bearing pad, the bearing pad may have separate configurations for low speed and high speed applications such that boundary lubrication is achieved under low speed conditions and dynamic lubrication is achieved under high speed conditions.

Abstract: Apparatus and a method for protecting a steam turbine from damage due to moisture are disclosed. The temperature and pressure of the incoming steam are monitored to determine if sufficient superheat energy is available to assure that the steam will flow through the turbine in the gaseous phase. The same inputs may be utilized to determine under and over pressure steam conditions. Once a fault condition is detected, operation of the turbine will be automatically interrupted.

Abstract: An assembly for mounting and removing a hub from a shaft is disclosed. The combination of a cylinder and annular piston mounted about the cylinder defining a first and second cavity are utilized such that upon the application of pressurized fluid to the selected cavity the piston is displaced in a first direction for mounting the hub to the shaft and in a second direction for removing the hub from the shaft. Symmetrical apparatus adapted to be utilized with shafts having either left-handed or right-handed threads is additionally disclosed.