Power Generation Mechanical Contractor in Illinois

When Power Plants Call DePue Mechanical

Power plants contact DePue when mechanical work affects outage duration, system reliability, inspection readiness, equipment availability, or the required return-to-service date.

The scope may begin as a planned repair, inspection finding, equipment replacement, pressure-system modification, or emergent condition discovered after isolation. In many cases, several related work fronts must be coordinated under one outage schedule.

DePue helps plant teams evaluate the complete mechanical requirement rather than treating each valve, weld, gearbox, piping section, or equipment connection as an unrelated task.

For broader plant piping capabilities, review DePue’s industrial piping contractor services.

• A planned outage includes several mechanical work fronts
• Inspection findings have expanded the original scope
• Pressure piping or valve work requires qualified procedures
• NDE or PWHT must be integrated into the outage schedule
• HRSG, steam, or condensate components require repair
• Rotating equipment must be removed and replaced
• Crane work must be coordinated with other outage activities
• Confined-space mechanical repairs are required
• Replacement piping should be fabricated before isolation
• A large valve or component has restricted installation access
• One contractor is needed to coordinate several related scopes
• A mechanical failure is affecting plant availability or safety

Planned Outage and Emergent-Scope Execution

A fixed power-plant outage leaves little room for inaccurate field dimensions, delayed materials, inspection conflicts, unplanned crane interference, or repairs that are not ready for testing. The execution plan must account for what can be completed before isolation, what must wait until equipment is opened, and what has to be finished before startup.

DePue supports planned outages where piping, valve replacement, rotating-equipment work, heavy lifts, confined-space entries, radiography, heat treatment, machining, leak repairs, and system turnover may advance in parallel.

Emergent findings are addressed within the broader outage sequence. The plant team needs to understand how a newly identified repair affects labor, materials, inspections, access, testing, and the critical path before authorizing the work.

When field conditions permit, DePue can fabricate replacement piping, tie-in spools, valve assemblies, supports, and mechanical components before the outage. Learn more about our shutdown and turnaround piping services and pipe fabrication and prefabrication capabilities.

• Pre-outage walkthroughs and field verification
• Review of outage schedules and critical-path activities
• Tie-in, isolation, and system-boundary verification
• Equipment, valve, and piping scope review
• Material verification and replacement-spool planning
• Prefabrication before the outage begins
• Crane access and heavy-lift sequencing
• Confined-space work coordination
• Parallel mechanical work-front planning
• Coordination of NDE and inspection hold points
• Post-weld heat-treatment coordination where required
• Emergent-scope review and schedule impact assessment
• Testing, leak checks, and turnover planning
• Support through the return-to-service window

Power Plant Outage Reporting and Turnover

Plant teams need more than confirmation that crews are working. They need visibility into completed work, pending inspections, emergent scope, testing status, and activities that could affect the required return-to-service date.

DePue coordinates reporting and turnover requirements with the plant before the outage begins. The specific deliverables depend on the scope, owner requirements, inspection plan, and project responsibilities.

Defining these expectations early helps maintenance, operations, engineering, and project-management teams make timely decisions as the outage progresses.

• Daily progress by work front
• Manpower and shift status
• Short-interval or look-ahead planning
• Weld and material tracking
• NDE and PWHT status
• Inspection hold-point status
• Emergent-scope and field-change tracking
• Crane and equipment-changeout status
• Testing and leak-check status
• Punch-list progress
• Turnover documentation
• Mechanical completion and handoff status

Jackson Generation: 15-Day Planned Outage

DePue Mechanical supported a planned 15-day outage at Jackson Generation, a 1,200 MW natural-gas-fueled combined-cycle facility in Elwood, Illinois. The work covered Units 1 and 2 and required several mechanical work fronts to advance within the same fixed shutdown window.

The project combined ACC gearbox replacement, crane work, pressure-piping welding, valve and thermowell installation, radiography, post-weld heat treatment, confined-space repairs, HRSG work, gasket replacement, expansion-joint replacement, machining coordination, and SCR blower valve replacement.

The plant needed one contractor capable of coordinating rotating equipment, heavy lifts, specialty welding, inspections, confined-space work, instrumentation connections, leak repairs, and large-component replacement without extending the outage.

DePue executed the assigned mechanical scope within the scheduled outage window and coordinated the work toward a clean mechanical handoff at the end of the shutdown.

• Four ACC gearbox replacements
• Oil service on 48 additional ACC gearboxes
• 125-ton crane operations
• IP and LP drum-door removal and reinstallation
• A 2-inch 9-chrome valve replacement
• Four radiographic examinations and PWHT coordination
• Small-bore valve and thermowell work
• A 48-inch condenser strainer gasket replacement
• HRSG drain and lube-oil fitting repairs
• Internal welding of 144 tube-abandonment plates
• A 24-inch expansion-joint replacement
• HP-drum mesh and clip installation
• A 16-inch SCR blower butterfly-valve replacement
• Mechanical handoff within the outage window

Power Plant Mechanical Capabilities

DePue’s power-generation work extends beyond major outage packages. Repeat owner-direct assignments have included fuel-gas piping, startup strainers, filtration systems, boiler-feedwater repairs, HRSG supports, RO and demineralized-water piping, generator components, air compressors, access platforms, valves, and ongoing balance-of-plant maintenance.

Outage mechanical work: DePue supports planned repairs, emergent findings, piping and valve replacement, expansion joints, gaskets, instrumentation connections, confined-space work, equipment changeouts, and inspection-driven corrective repairs.

Code and pressure systems: DePue supports ASME code welding, pressure piping, boiler external piping, pressure-retaining equipment, qualified welding procedures, weld documentation, radiography, PWHT, testing, and inspection coordination when required.

Boiler, HRSG, steam, and condensate systems: Our work can include HRSG repairs, power boiler installation, high-pressure steam headers, feedwater and condensate systems, drains, pumps, skids, valves, supports, and equipment connections.

Equipment and heavy lifts: DePue supports rotating-equipment replacement, ACC gearbox work, equipment setting, crane and rigging coordination, positioning, alignment, structural supports, reassembly, and mechanical tie-ins.

Self-performed mechanical scope: DePue self-performs industrial piping, ASME code welding, pipe fabrication, equipment setting, structural supports, sheet-metal work, and related mechanical installation.

Coordinated specialty services: Depending on the project requirements, DePue coordinates crane and rigging resources, radiography, post-weld heat treatment, machining, authorized inspection, and other specialty services within the mechanical execution plan.

This structure gives plant teams one mechanical contractor responsible for coordinating the primary installation scope, specialty service dependencies, inspection timing, and mechanical turnover requirements.

Explore DePue’s ASME boiler and code welding capabilities, steam and industrial utility piping services, and equipment setting and structural steel services.

• Planned outage and shutdown mechanical work
• Emergent repair support during an active outage
• ASME code welding and pressure piping
• Boiler external piping
• Steam and condensate piping
• HRSG piping, drain, and component repairs
• Valve, thermowell, and instrumentation connections
• Expansion-joint and large-gasket replacement
• Radiography and PWHT coordination
• Hydrostatic testing and system verification support
• Rotating-equipment removal and replacement
• ACC gearbox replacement support
• Crane, rigging, and heavy-lift coordination
• Confined-space mechanical repairs
• Pipe fabrication and prefabrication
• Pumps, skids, vessels, and equipment setting
• Pipe supports, guides, anchors, and structural supports
• Planned maintenance and emergency mechanical response

Boiler, Steam-System, and Capital-Project Support

DePue’s power-generation capabilities extend beyond outage repairs. The company also supports larger boiler, steam-distribution, equipment-setting, and mechanical-construction scopes where field routing, thermal growth, heavy lifts, and system integration must be planned together.

At the Hennepin project, DePue supported Boiler 5 installation, boiler intake ductwork, steam and condensate piping, condensate-polisher skids, feedwater pumps, chemical-treatment systems, and a high-pressure steam-distribution header.

The 20-inch Schedule 60 carbon-steel steam header included expansion loops and cold-spring adjustments to account for temperature-driven movement. The equipment-setting scope included condensate-polisher skids and feedwater pumps weighing approximately 30,000 pounds.

The project demonstrates DePue’s ability to coordinate boiler systems, large-bore pressure piping, heavy equipment, supports, thermal-growth requirements, and mechanical tie-ins inside a constrained plant environment.

• Boiler 5 installation support
• Boiler intake ductwork installation
• Steam piping installation
• Condensate piping installation
• Condensate-polisher skid setting
• Feedwater pump placement
• Approximately 30,000-pound pump setting
• Chemical-treatment system installation
• Heavy crane picks and precision placement
• A 20-inch Schedule 60 high-pressure steam header
• Expansion-loop coordination
• Cold-spring coordination
• Field routing and tie-ins in tight spaces
• Coordination with plant teams, engineers, and other trades

How DePue Controls Power-Plant Outage Risk

Outage risk is controlled before and during field execution. The mechanical plan must address known scope, likely inspection findings, material requirements, work-area access, simultaneous operations, third-party inspection dependencies, testing, and the final turnover sequence.

DePue develops the work plan around the facility’s outage schedule, equipment list, repair scope, drawings, system conditions, crane constraints, inspection requirements, and expected return-to-service date.

The objective is to reduce uncertainty before isolation and maintain clear coordination when field conditions, inspection findings, or emergent repairs change the original plan.

For congested retrofits, equipment layouts, or fabrication planning, DePue can also support VDC, 3D laser scanning, and constructability coordination.

• Confirm the operating requirement and outage schedule
• Verify affected equipment, piping, valves, and systems
• Confirm field dimensions, materials, access, and tie-in points
• Identify critical-path work and inspection hold points
• Review material lead times and prefabrication opportunities
• Plan crane operations, rigging, staging, and lift sequences
• Coordinate confined-space and hot-work requirements
• Sequence simultaneous mechanical work fronts
• Coordinate NDE, PWHT, testing, and inspection activities
• Communicate emergent scope and schedule impacts
• Track field changes and completion requirements
• Complete punch-list and turnover documentation
• Support a clean mechanical handoff for plant restart

Safety and Quality Controls for Power Plant Work

Power-generation work requires more than completing the mechanical installation. The work must be supported by site-specific safety planning, qualified personnel, documented welding controls, inspection coordination, testing, and clear turnover requirements.

DePue combines its industrial safety program with field-level hazard identification, daily safety communication, confined-space coordination, hot-work controls, and project-specific requirements established with the facility before mobilization.

DePue’s published safety record includes more than 100,000 hours worked without an injury or incident and 15 consecutive years of Three Rivers Manufacturers’ Association safety recognition. Learn more about DePue’s industrial safety standards and performance.

For code-sensitive power-plant work, DePue supports qualified welding procedures, qualified welders, weld and material tracking, pressure testing, inspection hold points, and documentation required for the assigned scope.

DePue holds S, U, PP, and R Stamp capabilities for boiler systems, pressure piping, pressure vessels, and qualifying repair or alteration work. Review DePue’s ASME boiler and code welding capabilities.

Safety, quality, inspection, testing, and turnover expectations are reviewed before work begins so plant operations, maintenance, engineering, and project-management teams understand how the mechanical scope will be controlled.

• Site-specific safety planning
• Daily toolbox talks and safety communication
• Field-level hazard identification
• Confined-space work coordination
• Hot-work permitting and controls
• System-isolation coordination
• Qualified welding procedures
• Welder qualification and continuity
• Material and weld tracking
• NDE and PWHT coordination
• Inspection hold-point tracking
• Pressure-testing documentation
• Field-change communication
• Punch-list and turnover records

Why Power-Plant Teams Work With DePue

Power-generation mechanical contractors are not interchangeable. The difference becomes clear when several work fronts must be coordinated during one outage, a pressure-system repair requires documentation and inspection, or heavy equipment has to be removed and reset through limited access.

DePue brings piping, code welding, fabrication, equipment setting, maintenance, and field coordination together under one mechanical contractor. This reduces disconnected handoffs and helps the plant team maintain clearer control of schedule, inspections, field changes, and turnover.

By combining self-performed mechanical work with coordinated specialty services, DePue helps reduce disconnected handoffs between piping, welding, equipment, inspection, and turnover activities.

A local power-plant maintenance manager described DePue’s performance this way: “They respond quickly and efficiently… The quality of work is top notch.”

Review additional industrial and power-related work in DePue’s mechanical project portfolio.

• Experience with fixed-window power-plant outage work
• Multi-trade industrial mechanical capabilities
• S, U, PP, and R Stamp capabilities
• Pressure piping and pressure-retaining system knowledge
• Qualified welding procedures and documentation support
• Pipe fabrication and prefabrication
• Rotating-equipment and heavy-lift coordination
• Confined-space mechanical repair experience
• Steam, condensate, HRSG, and boiler-system capabilities
• Field support for emergent outage findings
• Coordination with plant teams, engineers, inspectors, and vendors
• Testing, turnover, and restart-readiness discipline
• Planned maintenance and 24/7 emergency response capabilities

What to Send DePue for a Power Plant Project

The project does not need to be fully defined before the first conversation. DePue can begin with the outage schedule, known repair list, inspection findings, equipment information, drawings, or photographs currently available.

Early review helps identify field-verification needs, material lead times, inspection dependencies, crane constraints, prefabrication opportunities, and activities that may affect the outage critical path.

Projects with issued drawings, specifications, or bid packages can be submitted through DePue’s quote and bid request form. Early-stage projects can begin with a power project planning call.

• Facility name and project location
• Planned outage dates and allowable duration
• Known mechanical repair list
• Inspection reports and deficiency findings
• Equipment names, model information, and weights
• Drawings, P&IDs, isometrics, and equipment layouts
• Photographs and videos of existing conditions
• Pipe sizes, materials, ratings, and operating conditions
• Valve, fitting, gasket, and instrumentation requirements
• Welding, NDE, and heat-treatment requirements
• Confined-space scope and entry conditions
• Crane, rigging, and lift constraints
• Testing and turnover requirements
• Bid documents and subcontractor scope packages
• Required return-to-service date

Start Based on Your Power Project Stage

Early planning: Use a power project planning call to discuss the plant objective, outage timing, known scope, and information currently available.

Field-dependent scope: Request a power plant walkthrough when existing conditions, equipment access, tie-in points, crane requirements, or constructability need to be reviewed onsite.

Issued bid package: Use the quote and bid request form when drawings, specifications, schedules, and subcontractor requirements are ready for review.

Active mechanical failure: Submit an emergency mechanical service request or call DePue Mechanical at 815-255-2500 when a piping, boiler, pressure-system, welding, or mechanical failure requires an urgent response.

Power Plant Mechanical Contractor FAQs

Power-plant mechanical projects often raise questions about outage execution, pressure piping, code welding, HRSG repairs, boiler systems, rotating equipment, heavy lifts, inspections, and return-to-service requirements.

The answers below explain how DePue Mechanical supports combined-cycle plants, cogeneration facilities, power boilers, and conventional generation facilities.

What does a power plant mechanical contractor do?

A power plant mechanical contractor installs, repairs, replaces, and maintains the piping, pressure systems, boilers, HRSG components, valves, rotating equipment, structural supports, and other mechanical systems required for plant operation.

The contractor may also coordinate outage planning, prefabrication, equipment setting, crane work, code welding, inspections, confined-space repairs, testing, and mechanical turnover.

Can DePue support a fixed-window power plant outage?

Yes. DePue supports planned outages involving piping, valve replacement, code-sensitive welding, rotating-equipment work, heavy lifts, confined-space repairs, HRSG work, instrumentation connections, leak repairs, testing, and turnover.

Outage planning may include field verification, material planning, prefabrication, crane sequencing, inspection coordination, labor planning, emergent-scope review, and support through the required return-to-service window. Review DePue’s shutdown and turnaround piping services.

Does DePue provide ASME code welding and pressure-piping support?

Yes. DePue supports ASME code welding, boiler welding, pressure piping welding, pressure vessel work, boiler external piping, and code-sensitive mechanical repairs for industrial facilities.

DePue holds S, U, PP, and R Stamp capabilities and supports qualified welding procedures, qualified welders, weld documentation, pressure testing, and authorized inspection coordination when required. Explore DePue’s ASME boiler and code welding capabilities.

Can DePue perform HRSG, boiler, steam, and condensate work?

Yes. DePue supports HRSG piping and drain repairs, industrial boiler installation, boiler external piping, high-pressure steam headers, condensate piping, feedwater systems, pumps, skids, valves, equipment connections, and related pressure-system work.

Learn more about DePue’s steam, condensate, and industrial utility piping services.

Can DePue coordinate rotating-equipment replacement and heavy lifts?

Yes. Depending on the project, DePue can support rotating-equipment removal and replacement, crane and rigging coordination, controlled lifting and lowering, equipment orientation, positioning, alignment, reassembly, structural supports, and mechanical tie-ins.

During the Jackson Generation outage, DePue replaced four ACC gearboxes using a 125-ton crane and completed oil service on 48 additional gearboxes. Review DePue’s equipment setting and heavy-lift capabilities.

What should a plant send DePue before an outage or mechanical project?

Useful information includes the facility location, outage dates, known repair list, inspection findings, equipment data, drawings, P&IDs, isometrics, photographs, materials, welding requirements, NDE requirements, confined-space scope, crane constraints, testing requirements, and return-to-service date.

Defined projects can be submitted through DePue’s quote and bid request form. Early-stage projects can begin with a power project planning call.

For an active mechanical failure, submit an emergency service request or call DePue Mechanical at 815-255-2500.

Last technically reviewed: June 2026