590 MW HRSG Installation — New Jersey


Riggs Distler was awarded the contract for the Combined Cycle Build as a full construction-takeover project when the previous contractor could not meet deadlines.

The new plant replaced the existing less-efficient coal generating units with a new 590 dual fuel combined-cycle power plant, equipped with GE’s 7HA.02 gas turbines and steam turbines housed in a turbine building. The combined cycle power plant uses gas and steam to generate power from the same amount of fuel. Natural Gas is fired in the gas turbine generator to generate electricity. Waste heat from the gas turbine is diverted towards the heat recovery steam generator (HRSG) to produce steam, which drives the steam turbine to generate additional electricity. As part of the total scope, the installation of HRSG duct work and alignment of the steam turbines. Tasks included:

  • 4,000+ BOP welds with no weld rejects.
  • Installation of a 590-watt HRSG and duct work
  • Installation of high-pressure piping and 500 chrome welds
  • Completing all the ACC duct work along with the alignment of fan motors
  • Complete alignment of a steam turbine
  • Installation of wishbone expansion joint from steam turbine to ACC duct work
  • Temporary steam-blowing piping installation and removal
  • Fabrication of over 14,000 linear feet of 100% field route, small-bore piping

Challenges Overcome

In order to give the project a fresh start with qualified personnel, Riggs Distler cleared all existing craft staff, assigned in-house supervision, generated a new execution plan and new schedule, and tooled the project more efficiently. We utilized our union contacts throughout the Eastern United States to supply the project with expert union craftsmen, who completed the project by the commercial operation date.

Due to the setbacks under the former contractor, this needed the project to proceed on an accelerated schedule. Riggs Distler installed over 2,500 feet of prefabricated pipe each week for 17 weeks in order to meet the initial deadline, and our crews completed the entire project successfully within the client’s timeline.

Results Delivered

By relying on our project management expertise, careful worksite supervision, and our detailed execution plan, Riggs Distler completed the power plant buildout to meet the client’s schedule. In total, our crews installed 14,000 feet of field-engineered pipe and expended 350,000 man-hours on the project. As a testament to the quality of our work, Riggs Distler was awarded a full maintenance contract for the future upkeep at the plant.