Thermal Power Plants

Thermal Power Plant Services & Solutions

On-site machining, turbine maintenance and component restoration for thermal power plants
Thermal power plants depend on large rotating machinery and precision mechanical components operating under demanding thermal and mechanical conditions.

Steam turbines, generators, shafts, bearing areas, machine beds, flanges and other critical equipment can gradually be affected by wear, corrosion, erosion, vibration, thermal cycling and dimensional changes.

PR Rolls provides specialised on-site machining, surface restoration, measurement, alignment and balancing services for thermal power plants and power generation equipment.

Our capabilities include:

• On-site machining
• Turbine maintenance and machining
• Precision milling and turning
• Line boring
• Grinding and precision finishing
• Shaft and journal repair
• Bearing seat and housing restoration
• Division plane machining
• Machine bed and bed plate milling
• Flange and sealing surface machining
• Dimensional restoration
• Industrial coatings and surface engineering
• Brush plating and localised repair
• Measurement and alignment
• Field balancing
• Workshop refurbishment of suitable components

The objective is to restore critical mechanical equipment efficiently while reducing unnecessary dismantling, transportation and replacement.

Inspect → Measure → Repair → Restore → Align → Verify

 

Maintenance Challenges in Thermal Power Plants

Heat, pressure, rotation and long operating cycles

Thermal power plant equipment operates under demanding conditions.

High temperatures, mechanical loads, rotating forces, steam, water and long operating cycles can gradually affect the condition of machinery and functional surfaces.

Typical maintenance challenges can include:

• Mechanical wear
• Corrosion
• Erosion
• Surface damage
• Dimensional wear
• Shaft and journal damage
• Bearing seat wear
• Bore geometry deviations
• Damaged sealing surfaces
• Division plane deterioration
• Machine bed deviations
• Misalignment
• Vibration
• Imbalance
• Damage discovered during outages and overhauls

The correct maintenance solution depends on what has deteriorated and what function the restored component must provide.

A damaged shaft may require dimensional restoration.

A turbine division plane may require precision milling.

A bearing housing may require line boring.

A rotating component may require alignment or field balancing.

PR Rolls approaches the problem from the condition of the equipment rather than from one predetermined repair technology.

 

On-Site Machining for Thermal Power Plants

Bring precision machining technology to the equipment

Large power plant components are often difficult, expensive and time-consuming to remove from their installed position.

On-site machining – also known as in-situ, field or portable machining – allows specialised machining equipment to be installed directly around the component.

PR Rolls can perform suitable machining operations where the equipment is installed, reducing the need to transport large components to an external workshop.

On-site machining capabilities include:

• Milling
• Turning
• Line boring
• Drilling
• Grinding
• Honing
• Precision finishing

This makes on-site machining particularly relevant for planned outages, turbine overhauls, generator maintenance, equipment modernisation and time-critical repair projects.

Instead of bringing the component to the machine tool, PR Rolls brings the machine tool to the component.

 

Steam Turbine Maintenance & On-Site Machining

Precision restoration for turbine-related mechanical components

Steam turbines depend on accurate mechanical geometry, alignment and surface condition.

Wear, corrosion, erosion, deformation or previous repairs can affect critical interfaces over the operating life of the turbine.

PR Rolls' on-site machining capabilities can support turbine maintenance and overhaul projects involving suitable mechanical components and surfaces.

Applications can include:

• Turbine shafts and journals
• Bearing areas
• Bearing housings
• Division planes
• Machine beds
• Bed plates
• Mounting surfaces
• Flanges
• Sealing surfaces
• Contact surfaces
• Other large precision-machined turbine-related components

Depending on the application, PR Rolls can combine measurement, machining, grinding, dimensional restoration and final verification within the same maintenance project.

 

Turbine Division Plane Machining

Restore flatness, contact and sealing geometry

Division planes are precision interfaces where accurate surface geometry and contact are important.

Wear, corrosion, deformation or previous maintenance can gradually affect flatness and surface condition.

Depending on the equipment, deviations can contribute to:

• Poor contact
• Steam leakage
• Sealing problems
• Alignment difficulties
• Uneven mechanical loading
• Installation problems

PR Rolls provides on-site milling of division planes using portable machining equipment.

The existing geometry can first be measured to establish the machining requirement.

The surface is then machined according to the required geometry and verified after completion.

Measure → Establish reference → Machine → Verify

 

Generator Maintenance Support

Mechanical restoration for generator-related equipment

Generators and their supporting structures contain large mechanical components where dimensional accuracy and alignment are important for reliable operation.

PR Rolls can support suitable generator maintenance projects involving mechanical components such as:

• Shafts and journals
• Bearing areas
• Bearing housings
• Machine beds
• Bed plates
• Mounting surfaces
• Frames
• Flanges
• Bores
• Other precision mechanical interfaces

Services can include machining, measurement, dimensional restoration, alignment and field balancing according to the component and maintenance requirement.

 

Shaft & Journal Repair

Restore worn dimensions instead of automatically replacing the shaft

Shafts and journals can develop wear, scoring, corrosion, surface damage or dimensional deviations during long-term operation.

For large power-generation equipment, complete shaft replacement can represent a major maintenance project.

Where the underlying component remains technically suitable, restoration may provide another option.

Depending on the condition, PR Rolls can combine:

Inspection → Measurement → Machining → Surface restoration → Grinding → Verification

Suitable restoration technologies can be selected according to the material, damage, required dimensions, surface condition and operating environment.

The objective is not simply to add material.

The objective is to restore the geometry, dimension and functional surface required by the application.

 

Bearing Seat & Bearing Housing Restoration

Precision restoration of critical bearing interfaces

Bearing areas are critical interfaces in rotating machinery.

Wear, fretting, corrosion or dimensional changes can affect the relationship between the bearing, shaft and surrounding machine structure.

Potential consequences can include:

• Incorrect bearing fit
• Misalignment
• Increased vibration
• Uneven loading
• Accelerated wear
• Reduced equipment reliability

PR Rolls provides on-site machining and dimensional restoration for suitable bearing seats and bearing housings.

Where necessary, restoration can be combined with precision measurement, line boring, grinding or application-specific surface restoration.

 

Line Boring & Bore Restoration

Restore aligned bores directly at the power plant

Large turbines, generators and other power plant machinery can contain multiple bores that must remain accurately positioned relative to a common centreline.

Wear, deformation, equipment modification or previous repair work can affect bore geometry and alignment.

PR Rolls provides portable line boring for suitable power plant components.

Applications can include:

• Bearing housings
• Machine frames
• Aligned bore systems
• Worn bores
• Damaged bores
• Large equipment structures
• Bores requiring dimensional correction

The existing geometry is measured before machining and the finished result can be verified after restoration.

Measure → Establish centreline → Machine → Verify

 

Machine Bed & Bed Plate Milling

Restore the foundation for accurate machinery alignment

Large rotating machinery depends on accurate mounting and reference surfaces.

Machine beds and bed plates can be affected by corrosion, wear, mechanical damage, deformation or modifications made during the operating life of the plant.

If these surfaces are no longer correct, the equipment installed on them may not have the required support or alignment.

PR Rolls provides portable milling for:

• Machine beds
• Bed plates
• Mounting plates
• Equipment foundations
• Frames
• Reference surfaces
• Contact surfaces

This can be particularly valuable during major overhauls, equipment replacement and modernisation projects.

Existing surfaces can be measured and machined to establish the geometry required for installation and alignment.

 

Flange & Sealing Surface Machining

Restore sealing geometry on-site

Flanges and sealing surfaces can deteriorate through corrosion, erosion, mechanical damage, thermal cycling or repeated assembly and disassembly.

Poor surface condition can affect the sealing interface and contribute to leakage.

PR Rolls provides on-site machining for suitable:

• Flanges
• Sealing faces
• Mating surfaces
• Contact surfaces
• Large circular interfaces

Machining can restore required flatness, geometry and surface condition without automatically removing the complete component from the plant.

The appropriate machining method and final surface are determined according to the component and sealing requirements.

 

Dimensional Restoration & Localised Repair

Repair only what has deteriorated

Many large power plant components remain structurally and mechanically valuable even when a limited area becomes worn or damaged.

Replacing the complete component because of local dimensional wear is therefore not always the most appropriate solution.

PR Rolls can evaluate technologies for restoring:

• Shafts
• Journals
• Bearing seats
• Bores
• Housings
• Seal areas
• Cylindrical surfaces
• Other worn mechanical interfaces

Depending on the application, restoration can combine machining, grinding, brush plating, thermal spraying or other suitable surface engineering methods.

The principle is straightforward:

Restore the affected dimension or functional surface while preserving the existing component where technically appropriate.

 

Brush Plating & Selective Electroplating

Localised dimensional restoration without unnecessary component replacement

Brush plating, also known as selective electroplating, provides a method for depositing metal onto specific areas of an existing component.

Unlike conventional tank plating, the complete component does not need to be immersed in a plating bath.

This makes the process particularly useful for large installed machinery and localised repair.

Suitable power-generation applications can include:

• Shafts
• Journals
• Bearing seats
• Bearing housings
• Seal areas
• Bores
• Local corrosion damage
• Generator-related components
• Turbine-related mechanical components

Depending on the application, selective plating can be used to restore worn dimensions, repair local surface damage or provide a functional metallic surface.

PR Rolls can combine brush plating with precision machining and grinding:

Measure → Machine / Grind → Prepare → Plate → Finish → Verify

 

Industrial Coatings & Surface Engineering

Protect and restore suitable power plant components

Wear and corrosion do not always require complete component replacement.

Where the underlying component remains technically suitable, functional coatings can restore or improve surface properties.

Depending on the application, PR Rolls can provide surface engineering solutions for challenges involving:

• Wear
• Corrosion
• Erosion
• Dimensional loss
• Surface damage
• Bearing areas
• Sealing areas

Thermal spray technologies can create engineered surfaces selected according to the component and operating environment.

The correct coating is determined by the complete application:

Component + Wear mechanism + Temperature + Corrosion environment + Required surface function = Surface solution

Not every coating is suitable for every thermal power plant application. Material, temperature, geometry, tolerances and operating conditions must always be considered before selecting the restoration method.

Measurement & Alignment

Accurate maintenance begins with accurate measurement

Machining or restoring a component without understanding its existing geometry can lead to unnecessary material removal or incorrect correction.

PR Rolls provides on-site measurement and alignment services for power-generation equipment.

Measurements can be used to determine:

• Alignment
• Centre lines
• Flatness
• Parallelism
• Level
• Shaft position
• Machine geometry
• Component position
• Dimensional deviations
• Reference points for machining

Measurement can be performed before maintenance to establish the existing condition and after machining to verify the result.

Measure → Analyse → Correct → Verify

This allows maintenance decisions to be based on actual equipment condition rather than assumptions.

 

Field Balancing of Rotating Equipment

Correct imbalance directly at the plant

Imbalance can contribute to vibration, increased bearing loads and mechanical stress in rotating equipment.

PR Rolls provides field balancing for suitable rotating equipment directly at the customer's site.

Balancing may be relevant following:

• Maintenance
• Repair
• Machining
• Surface restoration
• Component modification
• Changes in rotating mass
• Detected vibration or imbalance

Because vibration can have several causes, balancing should be considered together with equipment condition, alignment, bearing condition and component geometry.

For suitable removable components, PR Rolls can also provide dynamic balancing as part of workshop refurbishment.

 

Planned Thermal Power Plant Outages

Specialist maintenance within the available outage window

'Thermal power plant outages create a limited maintenance window for inspection, overhaul, repair and modernisation.

Large machining operations therefore benefit from detailed preparation before the shutdown begins.

PR Rolls can plan specialised on-site work according to:

• Component condition
• Component dimensions
• Required tolerances
• Machining scope
• Site access
• Portable equipment installation
• Measurement references
• Required surface condition
• Work sequence
• Available outage time
• Final verification requirements

Several operations can also be coordinated as one restoration project:

Measurement → Machining → Grinding → Surface restoration → Alignment → Balancing → Verification

The exact sequence depends on the equipment and maintenance requirement.

 

Planned Maintenance & Emergency Repairs

Support for both scheduled and time-critical maintenance

Not every maintenance requirement is discovered during planned inspection.

Unexpected wear, damage or dimensional problems can also be identified during operation or after equipment has been opened during an outage.

PR Rolls' portable equipment allows specialist machining capabilities to be mobilised directly to the plant for suitable repair projects.

Services can support:

Planned Maintenance
Restore known wear or dimensional deviations during scheduled outages.

Major Overhauls
Perform precision machining and restoration as part of turbine, generator or other equipment overhauls.

Modernisation Projects
Modify existing machine structures and mounting surfaces for changed equipment requirements.

Installation Projects
Machine accurate reference and mounting surfaces for new or replacement equipment.

Time-Critical Repairs
Restore damaged components directly at the plant where workshop repair would require extensive additional dismantling and transportation.

Modernisation & Installation Support
Adapt existing equipment for the next stage of its lifecycle
Thermal power plants can undergo modernisation during their operating life.

Replacement or upgraded equipment may require changes to existing mechanical interfaces.

PR Rolls' on-site machining capabilities can support suitable modernisation projects involving:

• Machine beds
• Bed plates
• Mounting surfaces
• Bearing areas
• Bores
• Frames
• Flanges
• Reference surfaces

Existing structures can first be measured and then machined to establish the required geometry for installation and alignment.

This makes on-site machining relevant not only for repair, but also for equipment upgrades and lifecycle projects.

 

Workshop Maintenance & Refurbishment

On-site where necessary. Workshop where appropriate.

Although PR Rolls specialises in on-site services, not every component needs to be repaired at the plant.

Suitable removable components can be transported to the PR Rolls workshop for more extensive refurbishment.

Depending on the component, workshop services can include:

• Inspection
• Measurement
• Mechanical maintenance
• Machining
• Grinding
• Dimensional restoration
• Industrial coating
• Precision finishing
• Dynamic balancing
• Final inspection

This provides two complementary maintenance routes:

Large or difficult-to-remove equipment → Service on-site

Suitable removable component → Workshop refurbishment

The correct service location is determined by the component and maintenance requirement – not by a predetermined service method.

 

Typical Thermal Power Plant Applications

PR Rolls' capabilities can be applied to suitable mechanical components throughout thermal power generation equipment.

Typical applications can include:

• Steam turbine-related components
• Generator-related mechanical components
• Shafts
• Journals
• Bearing seats
• Bearing housings
• Bores and aligned bore systems
• Division planes
• Machine beds
• Bed plates
• Mounting surfaces
• Frames
• Flanges
• Sealing surfaces
• Contact surfaces
• Rotating equipment
• Pumps and pump components
• Valve components
• Hydraulic components
• Other large precision-critical mechanical components

The deciding factor is not simply the type of component.

What has deteriorated, what geometry or surface function must be restored, and where can the work be performed most effectively?

 

Repair, Refurbish or Replace?

Make lifecycle decisions according to actual component condition

Wear does not automatically mean replacement.

At the same time, not every component should be repaired indefinitely.

The appropriate maintenance strategy depends on:

• Component condition
• Damage mechanism
• Material
• Remaining usable structure
• Required geometry
• Required tolerances
• Surface requirements
• Operating temperature
• Mechanical loads
• Future operating requirements

This creates three principal options:

Repair
Correct local damage, wear or dimensional deviations.

Refurbish
Restore a larger part of the component or assembly for continued operation.

Replace
Install a new component when continued restoration is no longer technically or economically appropriate.

PR Rolls helps customers evaluate suitable restoration technologies when repair or refurbishment remains a viable option.

 

Sustainable Maintenance for Thermal Power Plants

Extend the productive life of existing industrial assets

Large power-generation equipment represents significant material, manufacturing work and economic value.

When deterioration is concentrated in a limited mechanical interface or functional surface, restoring the existing component can provide an alternative to premature replacement.

PR Rolls' approach is based on condition:

Maintain → Repair → Restore → Upgrade → Extend lifetime

On-site services can also reduce the need to transport large components between the plant and external workshops.

The objective is practical: preserve technically suitable equipment, restore the functions that have deteriorated and replace components when restoration is no longer appropriate.

 

Why PR Rolls for Thermal Power Plants?

PR Rolls combines several specialist maintenance technologies within one service concept:

• On-site machining
• Turbine-related machining
• Portable milling
• Turning
• Line boring
• Precision grinding
• Shaft and journal restoration
• Bearing area restoration
• Division plane machining
• Machine bed and bed plate milling
• Flange and sealing surface machining
• Brush plating
• Industrial coatings
• Dimensional restoration
• Precision measurement
• Alignment
• Field balancing
• Workshop refurbishment

This allows maintenance to be approached as a complete restoration problem rather than as a series of isolated operations.

A worn component may require measurement and machining.

Another may require dimensional restoration.

A third may require machining, surface engineering and final grinding.

The objective remains the same:

Understand the condition → Restore what has deteriorated → Verify the result → Return the equipment to reliable operation

 

Frequently Asked Questions About Thermal Power Plant Services

What services does PR Rolls provide for thermal power plants?
PR Rolls provides on-site machining, milling, turning, line boring, grinding, shaft and journal restoration, dimensional restoration, industrial coatings, measurement, alignment and field balancing for suitable power-generation equipment.

Can PR Rolls support steam turbine maintenance?
Yes. PR Rolls' on-site machining capabilities can support suitable turbine maintenance and overhaul projects involving shafts, journals, bearing areas, division planes, machine beds, flanges, sealing surfaces and other large mechanical components.

Can turbine division planes be machined on-site?
Yes. PR Rolls provides portable milling for division planes and other large mating surfaces. Measurement can be used before machining to establish the existing geometry and after machining to verify the result.

Can worn turbine shafts and journals be repaired?
Depending on component condition and technical requirements, worn shafts and journals can be evaluated for dimensional restoration using machining, grinding and suitable surface restoration technologies.

Does PR Rolls provide line boring at power plants?
Yes. Portable line boring can be used for suitable bearing housings, machine frames and aligned bore systems where bore geometry needs to be restored directly on-site.

Can PR Rolls repair bearing seats and housings?
Yes. Depending on the damage, PR Rolls can combine measurement, machining, line boring, grinding, brush plating or other suitable dimensional restoration technologies.

Can PR Rolls machine flanges and sealing surfaces on-site?
Yes. Suitable flanges, sealing faces and mating surfaces can be machined directly at the plant to restore the required geometry and surface condition.

Does PR Rolls provide measurement and alignment services?
Yes. PR Rolls provides on-site measurement and alignment services for power plants and other heavy industries. Measurement can be integrated with machining and restoration work.

Does PR Rolls provide field balancing?
Yes. PR Rolls provides field balancing for suitable installed rotating equipment and dynamic balancing for suitable removable components at its workshop.

Can PR Rolls work during planned power plant outages?
Yes. On-site machining is particularly suitable for planned outages because machining, measurement, restoration and related maintenance can be performed directly where the equipment is installed.

Can several maintenance operations be combined in one project?
Yes. Depending on the component, PR Rolls can combine measurement, machining, grinding, dimensional restoration, coating, alignment, balancing and final verification within the same maintenance project.

Should a worn component always be repaired instead of replaced?
No. The correct decision depends on component condition, material, operating requirements, remaining service potential and technical requirements. PR Rolls' condition-based approach is to repair or refurbish where technically appropriate and replace when necessary.

 

Restore Critical Power Generation Equipment On-Site

Large thermal power plant components do not always need to be removed or replaced when critical dimensions or surfaces become worn.

PR Rolls brings specialised machining, grinding, measurement, surface restoration, alignment and balancing technologies directly to the equipment.

From turbine division planes and machine beds to shafts, bearing areas, bores and sealing surfaces, the starting point is the same:

What has deteriorated?
What geometry or function needs to be restored?
Which repair technology is appropriate?
How can the final result be verified?

Inspect → Measure → Repair → Restore → Verify → Return to operation