CASE STUDY
How IMI's EroSolve Flashing improved valve life cycles at Korea’s Pocheon CCPP
Written By IMI Publications
February 23, 2026
The Pocheon Combined Cycle Power Plant (CCPP) in northeastern Korea, which was first commissioned in July 2008 and has two 725 MW units, faced frequent valve failures in a critical turbine cooling line. These failures increased maintenance costs and reduced operational stability.
This case study demonstrates how our EroSolve Flashing valve solution extended the plant's valve lifecycle up to four times, ultimately enhancing reliability, reducing erosion, and significantly cutting downtime.
The challenge
The plant faced an issue with a key part of its system: a valve in the turbine cooling air (TCA) to the condenser line. This line operates under extreme conditions of approximately 200 bar differential pressure and at 326°C, similar to the boiler feedwater pump discharge and HP economiser outlet. The discharge to near-atmospheric pressure in the condenser was the cause of frequent flashing. Flashing in control valves creates high-velocity droplets that erode valve components, choke the flow, and reduce system efficiency. Identifying and mitigating flashing is essential to prevent damage and maintain reliable operation.
Typical flashing damage to valve internals, from left to right: seat damage, cage damage and plug damage caused by high velocity flashing flow
Initially, the plant used a disk stack type valve supplied by a third-party manufacturer for this application. However, frequent start-stop operations caused extensive damage to the trim parts over a very short period, making flow control impossible. This also led to ongoing pipe wall thinning and to reduced equipment reliability. As a result, the plant faced operational issues that required open maintenance and the repeated purchase of trim parts every 3 to 6 months.
The solution
To address frequent valve failures caused by severe flashing, our engineering team redesigned the valve internals with its EroSolve Flashing (ESF) solution. The ESF included a special trim with hardened trim material and a multi-path stage design using a pintle plug and a seat liner.
To mitigate erosion and improve operational stability, we relocated the flashing point to the downstream side of the plug and seat area, minimising damage to the seat. Our team implemented a specially designed seat to enhance sealing durability and introduced a multi-turn plug to gradually dissipate energy and reduce vibration and noise.
Key outcomes
We installed our EroSolve Flashing technology at the Pocheon plant in October 2021 and began operating in November 2021. After a full year of operation, the October 2022 inspection revealed:
Minimal erosion even under flashing conditions
No major maintenance required
An extension of the maintenance cycle from 3-6 to 18–24 months.
This performance was validated again in March 2025, proving the long-term value and reliability of the EroSolve Flashing solution. The plant now experiences fewer shutdowns, lower operating costs, and improved performance.
Technical improvements
Sealing performance has been enhanced by reducing seat and plug damage under high-pressure conditions.
The damage frequency has decreased, resulting in longer inspection and replacement intervals.
KJ Park, Mechanical Engineer at the Pocheon Plant, commented, “These improvements have led to greater operational stability and a noticeable reduction in maintenance costs.” The EroSolve Flashing product line is available in angle and globe valve configurations to accommodate various customer piping layouts and system requirements.
Example cut-through of an EroSolve Flashing valve highlighting the internal trim geometry used to control flashing and reduce erosion in severe service applications
Key specifications of EroSolve Flashing
Body type: Angle or globe
Flow direction: Flow to close (OTP)
Valve size range: 1" to 12"
Valve rating: up to 2500#
End connection: Butt-weld, socket-weld, flanged
Trim size range: 3/8” to 8”
Trim characteristics: Customised EQ%
Shut-off class: ANSI/FCI 70.1 class IV, class V
Design temperature: Maximum 550°C
Conclusion
Our successfully developed and implemented upgrade at the Pochean CCPP facility highlights the real-world impact of our application-specific technology. By replacing an underperforming valve with our EroSolve Flashing solution, the plant extended its maintenance intervals with a stable, erosion-resistant solution tailored for demanding service conditions in power generation.
If your power plant faces similar challenges, please visit EroSolve Flashing.
