Hydropower Plants

On-site machining, turbine maintenance and component restoration for hydropower plants

Hydropower plants depend on large rotating equipment where geometry, alignment, surface condition and dimensional accuracy are critical for reliable operation.

When turbine, generator or other power plant components become worn or damaged, removing them for workshop machining can require extensive dismantling, heavy lifting and transportation.

PR Rolls provides specialised on-site machining, measurement, surface restoration and field balancing for hydropower plants and large power generation equipment.

Our capabilities include:

• On-site machining
• Turbine and generator maintenance support
• Shaft and journal repair
• Bearing area restoration
• Line boring
• Milling and turning
• Grinding
• Flange and sealing surface machining
• Division plane machining
• Measurement and alignment
• Field balancing
• Industrial coatings and dimensional restoration

The objective is to restore critical geometry and functional surfaces directly at the power plant whenever technically appropriate.

Maintenance Challenges in Hydropower Plants

Large rotating equipment requires precision

Hydropower equipment operates for long periods under demanding mechanical and hydraulic conditions.

Over time, wear, corrosion, erosion, vibration or mechanical damage can affect critical components.

Typical maintenance requirements can include:

• Shaft and journal wear
• Bearing area damage
• Worn or damaged sealing surfaces
• Flange surface damage
• Division plane irregularities
• Misaligned or worn bores
• Corrosion and erosion
• Dimensional deviations
• Misalignment
• Runout
• Vibration and imbalance

Small geometrical deviations can become significant when they affect large rotating machinery.

PR Rolls therefore combines machining with measurement and verification.

Inspect → Measure → Machine → Restore → Align → Verify

On-Site Machining for Hydropower Plants

Machine large components where they are installed

Hydropower turbines, generators and their supporting structures contain large components that can be difficult to remove from the plant.

PR Rolls brings portable precision machining equipment directly to the power station.

Depending on the repair requirement, our on-site machining capabilities include:

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

On-site machining can be integrated into planned outages, turbine overhauls, modernisation projects and time-critical repairs.

Instead of transporting a large component to a conventional machine shop, PR Rolls can machine suitable equipment in its installed environment.

Bring the machine tool to the component.

Turbine Maintenance & On-Site Machining

Restore critical turbine components during overhaul

Hydropower turbine maintenance can involve large components where accurate geometry and alignment are essential.

During an overhaul, inspection may reveal worn, damaged or dimensionally incorrect surfaces that require restoration before the turbine can be reassembled.

PR Rolls can support turbine maintenance with services such as:

• On-site milling
• Turning
• Grinding
• Line boring
• Shaft and journal restoration
• Bearing area machining
• Division plane machining
• Flange and sealing surface restoration
• Measurement and dimensional verification

Several machining operations can be coordinated during the same outage.

The objective is to restore the required dimensions, geometry and contact conditions while minimising unnecessary removal of large components from the plant.

Generator Maintenance Support

Precision machining for large generator components and structures

Generator maintenance can also require dimensional correction and restoration of large machine structures.

PR Rolls' portable machining capabilities can support suitable generator maintenance applications involving:

• Bearing areas
• Shafts and journals
• Machine beds
• Mounting surfaces
• Division planes
• Flanges
• Frames and structures
• Other precision interfaces

Measurement can be performed before machining to establish the existing geometry and again after the work to verify the result.

This creates a controlled maintenance process:

Measure → Machine → Measure → Verify

Shaft & Journal Repair

Restore worn rotating surfaces

Shafts and journals are critical interfaces in hydropower rotating equipment.

Wear, corrosion, fretting or bearing-related damage can affect local areas even when the main component remains suitable for continued service.

Depending on the condition and application, PR Rolls can combine:

• On-site turning
• Grinding
• Metallic coating or plating
• Dimensional restoration
• Precision finishing

The worn area can be restored and machined to the required final dimensions.

This can provide an alternative to replacing a complete valuable component because of localised surface damage.

Bearing Area & Housing Restoration

Restore geometry and dimensional accuracy

Bearing areas depend on accurate dimensions, geometry and alignment.

Wear or mechanical damage can affect shafts, bearing seats, housings and related interfaces.

PR Rolls can provide suitable repair methods including:

• Turning
• Grinding
• Line boring
• Dimensional restoration
• Metallic coating
• Precision finishing
• Measurement and alignment

The appropriate method depends on whether the deterioration affects the shaft, housing, bore or another functional interface.

Line Boring

Restore aligned bores directly at the power plant

Large hydropower machinery can contain bearing housings and other bore systems where accurate alignment is essential.

PR Rolls provides on-site line boring for suitable large industrial components.

Line boring can be used to restore:

• Worn bearing bores
• Misaligned bores
• Large machine housings
• Aligned bore systems
• Other precision cylindrical interfaces

Where material has been lost, dimensional restoration can be combined with machining where technically appropriate.

Performing the work on-site can avoid transporting large structures to an external workshop.

Division Plane & Machine Surface Milling

Restore flatness and contact conditions

Large turbines, generators and other power plant machinery contain division planes, machine beds, mounting surfaces and other critical interfaces.

Wear, corrosion, deformation or mechanical damage can affect flatness and contact conditions.

PR Rolls provides portable on-site milling for surfaces including:

• Turbine division planes
• Machine beds
• Bed plates
• Mounting surfaces
• Frames
• Foundation-related interfaces
• Contact surfaces

Machining can restore the required geometry directly at the plant and can be combined with precision measurement before and after the work.

Flange & Sealing Surface Machining

Restore sealing surfaces without unnecessary dismantling

Reliable sealing depends on correct surface geometry.

Corrosion, wear, deformation or mechanical damage can affect flange and mating surfaces and contribute to leakage.

PR Rolls provides on-site turning and machining for suitable:

• Flanges
• Mating surfaces
• Sealing faces
• Circular interfaces
• Other large precision surfaces

The damaged surface can be machined directly at the plant to restore the required geometry and contact condition.

Measurement & Alignment

Establish the correct geometry before machining

Precision machining starts with understanding the actual condition of the equipment.

PR Rolls provides measurement and alignment services for power generation equipment, including rotating machinery, shafts, machine foundations and other critical structures.

Measurement can be used to:

• Determine existing geometry
• Identify alignment deviations
• Measure runout
• Establish machining references
• Support installation and assembly
• Verify repaired components
• Confirm final geometry

Combining measurement with machining allows repair decisions to be based on actual dimensional data.

Field Balancing

Correct imbalance in rotating equipment

Imbalance can contribute to vibration and increased mechanical loading in rotating machinery.

PR Rolls provides field balancing, also known as on-site balancing, for suitable rotating industrial equipment.

Balancing at the power plant can be particularly valuable when the rotating component is difficult to remove or when correction needs to be integrated into a planned maintenance outage.

Field balancing can be combined with:

• Vibration measurement
• Inspection
• Alignment
• Machining
• Surface restoration
• Final verification

Where components can be efficiently removed, workshop dynamic balancing is also available.

Industrial Coatings & Surface Restoration

Restore and protect worn functional surfaces

Some hydropower maintenance problems involve surface deterioration rather than complete structural failure.

Wear, corrosion, erosion or dimensional loss can affect shafts, bearing areas and other critical machine surfaces.

Depending on the application, PR Rolls can provide:

• Thermal spray coatings
• Metallic coatings
• Brush plating
• Dimensional restoration
• Grinding
• Precision finishing

Modern carbide-based thermal spray technologies can also provide alternatives to traditional hard chrome plating in suitable applications.

The correct surface solution is selected according to:

Component + Damage mechanism + Operating environment + Required surface function

Planned Hydropower Outages

Combine multiple services during the same maintenance window

Hydropower maintenance and turbine overhauls are often performed within carefully planned outage schedules.

When machining is required, time spent dismantling and transporting large components can consume a significant part of the available maintenance window.

PR Rolls can coordinate several operations directly at the power plant:

Measurement → Milling → Turning → Line boring → Grinding → Surface restoration → Alignment → Balancing → Verification

Combining multiple capabilities through one service partner can simplify project coordination and help keep repair work within the planned outage.

Modernisation & Installation Support

Precision machining for upgrades and equipment modifications

Hydropower plants can remain in operation for decades, during which turbines, generators and supporting systems may be modernised or upgraded.

Modernisation can create new requirements for:

• Mounting surfaces
• Bores
• Machine beds
• Flanges
• Interfaces
• Alignment
• Dimensional correction

Portable machining makes it possible to modify suitable existing structures directly at the plant.

PR Rolls can combine measurement and machining to establish the required geometry for new or modified equipment.

Workshop Refurbishment

Complete restoration for removable components

Not every component needs to be repaired at the power plant.

Suitable removable components can be refurbished at the PR Rolls workshop.

Depending on the component, refurbishment can include:

Inspection → Measurement → Mechanical repair → Machining → Grinding → Surface restoration → Coating → Precision finishing → Dynamic balancing

This provides two complementary approaches:

Large or installed equipment → On-site service

Suitable removable components → Workshop refurbishment

The appropriate method depends on component size, condition, tolerances and maintenance requirements.

Typical Hydropower Applications

PR Rolls' technologies can be applied to suitable components throughout hydropower maintenance and overhaul projects.

Applications can include:

• Turbine components
• Generator components and structures
• Shafts and journals
• Bearing areas
• Bearing housings
• Aligned bores
• Division planes
• Machine beds and bed plates
• Mounting surfaces
• Flanges and sealing surfaces
• Frames and large machine structures
• Other precision-critical power generation components

The deciding factor is not simply the type of equipment.

The key question is which geometry, dimension or functional surface needs to be restored.

Repair, Refurbish or Replace?

Base the maintenance decision on actual condition

Large hydropower components represent significant material, manufacturing and installation value.

Local wear or surface damage does not automatically mean that the complete component must be replaced.

Depending on condition, the appropriate strategy may be to:

Repair – correct local damage.

Machine – restore dimensions and geometry.

Restore – rebuild a worn functional area.

Recoat – provide a renewed functional surface.

Refurbish – restore the complete component.

Modernise – modify existing equipment for new requirements.

Replace – when continued restoration is no longer technically appropriate.

This condition-based approach can help extend the useful service life of existing hydropower equipment.

Why PR Rolls for Hydropower Plants?

 

Combine portable machining with measurement and surface restoration

Hydropower maintenance often requires several specialist technologies within the same overhaul.

A worn journal may require dimensional restoration and grinding. A bearing housing may require line boring. A turbine division plane may require precision milling. A rotating component may require measurement, alignment and balancing.

PR Rolls combines:

On-site machining + Milling + Turning + Line boring + Grinding + Measurement & alignment + Field balancing + Surface restoration

Our experience in on-site machining extends to power generation and other large-scale industries where critical equipment must be restored within demanding maintenance schedules.

The objective is straightforward:

Restore the geometry. Restore the surface. Verify the result. Return the equipment to operation.

Frequently Asked Questions About Hydropower Services

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

Can turbine components be machined at the power plant?
Yes. Suitable turbine components and machine structures can be machined using portable equipment directly at the power plant, depending on accessibility, geometry and repair requirements.

Can PR Rolls machine turbine division planes?
Yes. PR Rolls provides on-site milling for division planes and other large precision surfaces used in turbine and power generation maintenance.

Can worn turbine or generator shafts be repaired?
Suitable shaft and journal areas can often be restored through turning, grinding and dimensional restoration technologies. The appropriate method depends on the damage, material and technical requirements.

Does PR Rolls provide line boring at hydropower plants?
Yes. On-site line boring can be used for suitable bearing housings, aligned bores and other large cylindrical interfaces requiring dimensional or alignment restoration.

Does PR Rolls provide measurement and alignment?
Yes. PR Rolls provides measurement and alignment for power generation applications, including rotating equipment, shafts and machine foundations.

Can PR Rolls perform field balancing?
Yes. Field balancing can be performed for suitable rotating equipment and can be combined with measurement and other maintenance operations during the same outage.

Can PR Rolls support hydropower modernisation projects?
Yes. Portable machining and measurement can support suitable modernisation and installation projects where existing bores, mounting surfaces, machine beds, flanges or other interfaces require modification or dimensional correction.

Restore Critical Hydropower Equipment On-Site

Hydropower equipment is built for long service life, and local wear or dimensional damage does not always require replacement of the complete component.

PR Rolls combines on-site machining, turbine maintenance support, shaft and journal restoration, line boring, precision milling, measurement, alignment, field balancing and surface engineering to restore suitable hydropower equipment.

From turbine division planes and bearing areas to shafts, flanges and generator structures, the maintenance process begins with understanding the actual condition and required geometry.

Inspect → Measure → Machine → Restore → Align → Verify → Return to operation

Contact PR Rolls to discuss an upcoming hydropower outage, turbine overhaul, modernisation or repair requirement.