Plant diagnostic technology that overcomes the uptime–safety dilemma, evolving into predictive maintenance

Text: Wookyeom Kim. This article was originally published in The Korea Industry Daily, In April 2026  

Valmet’s Flow Control business area confirmed that it has completed the installation and inspection of 50 Neles™ ValvGuard PST online diagnostic devices for ESD valves  at Lotte Chemical’s Daesan naphtha cracking center (NCC) and aromatics (BTX) plants.
The Daesan plant is a core petrochemical facility where high-temperature and high-pressure processes operate continuously, making the reliability of ESD valves (used to shut down processes in emergency situations) absolutely critical.

Traditionally, the plant industry has relied either on full-stroke testing, completely opening and closing valves during turnaround periods, or on limited functional checks during operation. Due to long testing intervals, it has been difficult to detect issues such as valve sticking or slow response in advance.

The Neles ValvGuard PST operates using a partial stroke test (PST) method, which moves the valve only within a limited range instead of fully opening or closing it. This approach minimizes the impact on process flow while enabling precise monitoring of the valve’s response characteristics and operating condition.

Neles™ ValvGuard™ VG9000 – intelligent safety solenoid

The diagnostic system collects real-time data on valve position, actuator pressure, response time, and load variations. Based on repeated measurement data, it tracks condition changes, enabling early detection of anomalies and providing a basis for planning maintenance in advance.
Automated test sequences and protective logic ensure that operations remain within defined limits, reducing the risks associated with testing during operation. A system has also been established to perform tests remotely and review results immediately.

Kim Jaemin, Assistant Manager, Lotte Chemical Daesan plant

Kim Jaemin, Assistant Manager at Lotte Chemical’s Daesan plant, commented, “Being able to periodically check valve conditions within a range that does not affect the process provides a practical basis for establishing preventive maintenance plans.”

The device adopts a microcontroller-based architecture to perform integrated diagnostics of the valve, actuator, and solenoid. Unlike conventional solenoid valves that are limited to simple open/close functions, it combines partial stroke testing with diagnostic capabilities to enable data-driven condition management. It meets the SIL 3 (Safety Integrity Level 3) certification in accordance with the international safety standard IEC 61508 and can be integrated with higher-level plant management systems via HART and fieldbus communication.

"This positive experience at the Daesan plant opens up an excellent opportunity for Valmet to explore and further develop similar high-risk applications where unexpected equipment failures can lead to significant production losses."

Lukas Kim, Sales Engineer, Valmet Flow Control business area, South-Korea

Lukas Kim, Sales representative at Valmet, emphasized, “By utilizing diagnostic data, ESD valves can be managed quantitatively, enabling both improved equipment safety and maintenance efficiency.”

Safety management in the plant industry is evolving from reactive approaches to data-driven predictive maintenance. Building a proactive prevention system, by linking accumulated diagnostic data with plant management systems to enhance process stability, is emerging as a critical factor for business sustainability.