Description :
The base upon which the gas turbine is mounted is a structural-steel fabrication of welded  steel beams and plate. It forms a single platform which provides support upon which to mount  the gas turbine.

In addition, the base supports the gas turbine inlet and exhaust plenums. Lifting trunnions and supports are provided, two on each side of the base in line with the structural cross members of the base frame. Machined pads, three on each side of the bottom of the base, facilitate its mounting to the side foundation. Two machined pads, atop the base frame are provided for mounting the aft turbine support.


Description :

The gas turbine is mounted to its base by vertical supports. The forward support is located at the lower half of the vertical flanges of the forward compressor casing, and the aft two support-legs are located on either side of the turbine exhaust frame.

The forward support is a flexible plate that is bolted and doweled to the turbine base, at the forward base cross frame beam, and bolted and doweled to the forward flanges of the forward compressor casing.

The aft supports are leg-type supports, located one on each side of the turbine exhaust frame. Both vertical support legs rest on machined pads on the base and attach snugly to the turbine exhaust-frame-mounted support pads. The legs provide center-line support to supply casing alignment.

Fabricated to the outer surface of each aft support leg is a water jacket. Cooling water is circulated through the jackets to minimize thermal expansion of the support legs and assist in maintaining alignment between the turbine and the generator. The support legs maintain the axial and vertical positions of the turbine, while a gib key coupled with the turbine support legs maintains its lateral position.

Drawings of the turbine supports.

Forward Turbine Support

 Aft Turbine Support Leg 
(one on each side)


Description :
A gib key is machined on the lower half of the turbine shell. The key fits into a guide block which is welded to the turbine base aft cross beam. The key is held securely in place in the guide block with bolts that bear against the key on each side.

This key-and-block arrangement prevents lateral or rotational movement of the turbine while permitting axial and radial movement resulting from thermal expansion.

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