Safety Roundtable: Reliable alarms critical to personnel safety

Safety is the first discussion topic at Frame 6 meetings and most other user-group conferences. This roundtable is led by Gillis, whose position as gas-turbine technology lead for ExxonMobil’s worldwide fleet of engines gives him a global perspective to share with attendees. OSHA is not global and America does not have all the answers.

Gillis’ first slide was designed to stimulate thinking, aided by morning coffee. He put up a list of possible topics in three categories to get the discussion rolling, including:

General  

    • Life-saving rules.

    • Compartment entry.

Safety systems

    • Hazardous-gas detection.

    • Fire suppression.

Maintenance

    • Fall protection and PPE (Personal Protective Equipment).

    • Scaffolding and access.

    • Safety professionals and other personnel.

    • Inlet-filter-house fire prevention and escape.

    • Rescue considerations.

    • Fuel-nozzle failures resulting in a casing breach.

The first topic introduced concerned a unit trip on high oil temperature without alarm notification. Plus, recorded data did not indicate any change in temperature. The alarm for high oil pressure also was found faulty. The gremlin was a loose wire. Termination strip was repaired and the unit returned to service in the late afternoon. The user sharing the experience said termination strips can take just so much abuse and suggested that the person you assign to work on them should be someone you trust with a screwdriver.

An attendee shared his experience with a black-start unit brought up to full speed/no load (FSNL) that couldn’t be synchronized. The safety issue was that the Mark VI auto-synch feature was not turned off and the breaker closed with electricians in the generator auxiliary cabinet. The group was polled to see how many attendees close the generator breaker with someone in the GAC. No hands were raised.

One outcome from this incident was a modified startup procedure that requires operators to confirm excitation at 50% speed on black-start units. Also, electricians must check the GAC to confirm there are no faults prior to startup. Finally, a warning sign was hung on the cabinet door and operators are required to issue stop-work permits to electricians during engine starts.

Another technician mentioned that PPE safety boxes are located at strategic locations around his plant. They include PPE-use requirements for specific tasks and equipment. Tooling also is located throughout the plant. One example given was the placement of toolboxes on top of the HRSGs to reduce the need for technicians to travel back and forth to a central location, saving time and reducing the risk of injury.

One user offered an observation that safety procedures often are “ignored” between outages, when the safety “police” are not on duty.

Fire protection is discussed at every meeting. Last year a user mentioned that the CO2 system at his plant discharged before the alarm activated. Having reliable alarms and external lighting to warn of a release is critical to personnel safety. One got the impression that controls for fire-suppression systems—water mist and CO2—were not as reliable as they should be. Hard to find qualified vendors to maintain these safety systems, according to a few participants. One said he double-checks third-party certifications and any work done on the system.

Attendees were urged to check package integrity for leaks because if leakage persists—at louvers, for example—you can’t maintain the inert atmosphere while the unit cools. Louver mechanisms on legacy units were identified as a problem area and characterized as being “rinky-dink.”

Chairman Gillis noted several safety threads on the organization’s online user forum—including experience with optical flame detectors, how to deal with ill-fitting compartment doors and hardware replacement to correct, functional tests to confirm proper operation of water-mist fire-suppression systems during unit commissioning, opening of compartment doors with the CO2 system activated, and alternatives to IGD combustibles detectors.

He also listed in his presentation the Technical Information Letters (TILs) published by the OEM that should be reviewed by the safety manager at each plant. If you don’t have copies of the pertinent documents, request them from your plant’s GE representative.

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