An inlet guide vane apparatus includes a compressor end cap connectable with a main body of a compressor housing and a housing portion connected to the end cap. The housing portion and the end cap cooperatively define a fluid flow passageway and guide vane openings extending into the fluid flow passageway. The inlet guide vane apparatus also includes a ring gear rotatable relative to at least one of the housing portion and the end cap and guide vanes connected to the housing portion and the end cap. Each guide vane extends through one of the guide vane openings and includes a vane gear operably connectable with the ring gear and disposed at an exterior of the housing portion and a vane disposed within the fluid flow passageway. Each guide vane is rotatable such that an orientation of the vane within the fluid flow passageway is selectively adjustable.

A wear-reducing coating system for a substrate includes an innermost layer disposed on a substrate and an outermost layer disposed on the innermost layer. The innermost layer has higher load-carrying capacity than the outermost layer and the outermost layer has a lower coefficient of friction than the innermost layer. A method of applying a wear-reducing coating to a substrate and a method of applying a coating to a split ring casing for a high pressure compressor are also disclosed.

An inlet guide vane apparatus for imparting a pre-swirl motion to a fluid flow entering an inlet of a compressor housing. The apparatus including an inner surface defining a fluid flow passageway extending between an inlet and an outlet along a fluid flow direction. An apparatus housing defines guide vane openings extending into the fluid flow passageway.

The inner surface includes an inlet portion extending axially from the inlet to an axial end upstream from the guide vane openings. The inlet portion of the inner surface includes an inwardly tapered portion that tapers radially inward as the inner surface extends along the fluid flow direction. The inner surface further includes an outwardly tapered portion positioned downstream from the inwardly tapered portion that tapers radially outwards as the inner surface extends along the fluid flow direction.