Understanding when to use online Trevi testing versus offline workshop testing is critical for minimising downtime while maintaining safety compliance.
Online Testing
Online testing applies a measured external force to the valve spindle while the plant stays in service, so the set pressure can be calculated without isolating the valve or taking a shutdown. It is the right choice when the unit cannot be stopped, when the valve population is large, or when the effect of process temperature on the spring needs to be captured.
Offline Testing
Offline workshop testing removes the valve to a test bench, where set pressure, seat tightness, blowdown, and lift can all be verified and the valve stripped, inspected, and refurbished. It is the more complete picture, and it is the only option where the valve is already suspect.
Choosing Between Them
Most plants run both: online testing on a rolling programme between turnarounds, and offline overhaul during the shutdown itself for anything the online results flag.
Talk to our engineering team about the right mix for your plant.