AP4 Group – Full-Service Heavy-Duty & Aeroderivative Industrial Gas Turbine Maintenance Provider.

TC&E is dedicated to ensuring that our customer’s steam turbine control systems are being properly configured, updated, and maintained to maximize turbine availability and reliability, especially as related to startup, while minimizing the impact on maintenance and capital budgets.

Let us bring our industry-best capabilities to your control systems.

Systems We Support Include:

  • MHC
  • SpeedTronic™
  • MKII
  • MKIV
  • MKV
  • MKVe
  • MKVI
  • MKVIe
  • IDOS
  • Windows HMI (NT, XP, Windows 7&10 -Cimplicity Screens

Servcies Offered:

  • Valve Calibration and Line UP
  • Performance Verification
  • I&C Calibrations & Loop Checks
  • HMI File & Record Organization
  • Startup Support Pre/Post Outage
  • HMI Backup and Restoration
  • Troubleshooting & Repair
  • Thermocouple Cerification
  • Loop & Function Checkout
  • Vibration & Monitoring



AP4 Power Services specializes in controls, excitation, and LCI systems on GE™ heavy-duty gas and steam turbines. These services include a wide variety of controls maintenance, troubleshooting, and system upgrades. Our OEM-trained field engineers are here to ensure your equipment operations are reliable and efficient.

Power plant personnel look to AP4 Power Services when they are seeking a trusted non-OEM service provider that can help develop and implement customized control system projects. We are a trusted installation partner for many non-OEM equipment vendors throughout the industry.

From basic troubleshooting to DLE Mapping and mechanical service and maintenance, AP4 Power Services can meet all of your aeroderivative needs. Our expert team of Controls & Mechanical Field Engineers are ready and able to provide the on-site support you require.

Industry Benefits


Using the latest technology, components, and lessons learned through decades of experience, AP4 Power Services can ensure complete reliability for both start-up and continuous operation.


This is the key to success in today’s competitive power markets. Heat Rate, Capacity, Start-Up, and Maintenance Costs are critical to the success of aging power plants.


Spending good money where it makes the most difference! We understand that O&M budgets are shrinking, so we work with the plants to understand where and when to repair, replace, or upgrade for maximum return.


Aging systems can continue to provide reliable service for many years to come with the proper service, maintenance, and repairs. Push your upgrades out 5-10 years with confidence.