Turning Gear Apparatus

Throttle Valve Seat Changeout

The projects shown here deal with the changing of the throttle valve seats on various Westinghouse steam turbines. Similar operations are performed to change the main stop valve seats on many General Electric turbines, though some of them are bolted in, and some are welded. The work is similar but perhaps easier on a GE turbine because the valves are usually oriented vertically, and not horizontal as are these Westinghouse valves.

The work generally consists of the following:

Cut the seal weld from the old seat and pull it out. Machine the gasket face and spigot fit bore in alignment and perpendicularity with the axis of the seat bore. Skim cut the seat bore to establish size and roundness. Machine the new seat to proper sizes, shrink, and install. Complete the seal weld.

Reheat Stop Valves

Uintah Machine has worked on quite a few Reheat Stop Valves (RHSV or RSV). Those shown here are on Westinghouse turbines. Besides on site work like this, we also work on the bearing end caps and the yoke brackets (AKA “mummy case”) in the shop.

Pressure Reducing Valves

Pressure Reducing (or Relief) Valves (PRV’s) function to divert the water and pressure from the turbine should an untoward incident take place, and they are designed to open in an instant when tripped, thereby preventing serious pressure spikes in the penstock. The photos below show various boring bar setups used in the rebuild of these valves.

We also bolted in stainless liner plates below the seat ring of one of these PRV’s where the wall of the valve had been largely destroyed by the forces of cavitation. This part of the valve was mostly spherical, and so it was necessary to build a special hydraulic drill that would adjust to all angles or elevations and rotation in order to get the holes radial to the center point of the sphere.

Nozzle Block

Uintah Machine changes out nozzle blocks when required to do so. The photos shown here depict jobs on a couple of different Westinghouse turbines. The general procedure is to remove the old bolts (shearing the retaining pins in the process), remove the nozzle blocks, then machine the interface with the nozzle chambers. Thereafter the new blocks are lapped in to contact with the nozzle chambers, bolted up, and the bolt heads pinned.


Uintah Machine (and predecessors) has been building and rebuilding coal, salt and potash, and trona mining equipment beginning in the mid 1980s. In that time we have worked on a vast array of equipment by other manufacturers. In addition, we have developed an extensive product line of our own.

Download a Heavy Duty Three Axle Trailer brochure here.

Download a Belly Dump Gravel Trailer brochure here.

Download a Concrete Trailer brochure here.

Download an Underground Crane brochure here.

Download a Dump Bed Trailer brochure here.

Download a Miner, Shearer, and Combination Trailer brochure here.

Download a Push Plate Trailer brochure here.

Download a Shield Hauler brochure here.

Download a Special Purpose Trailer brochure here.

Download a Supply Trailer brochure here.

Download a Tool Trailer brochure here.

Download a Water Wagon brochure here.

Download a Pipe Handling Trailer brochure here.

Download a Belt Winder brochure here.

General Machine Shop

Uintah Machine (and predecessors) has been in the machine shop business since the mid 70’s.  After more than four decades in business, there are not many projects that come along that are not at least similar to things we have already done multiple times.

Download a General Machine Shop Service brochure here.

Download a Field Machining brochure here.

Download a Gears, Sprockets, and Gearboxes brochure here.

Download a Portable Machine Shop brochure here.

Welding and Fabrication

Uintah Machine has done a myriad of fabrication jobs over the last several decades. Most of our projects are also engineered by Uintah Machine, as well. They include conveyors, screw conveyors, chutes, hoppers, and trailers, as well as entire machines such as diesel powered coal haulers, feeder-breakers, oscillating feeders, etc.

Modification of Throttle Valve for Spiral Wound Gasket

Power Rolls