Tag: Need
Job Covey Wallace: 5 Fast Facts You Need to Know – Heavy.com
Job Covey Wallace: 5 Fast Facts You Need to Know Heavy.com
Job Covey Wallace is a missing Marine who disappeared in Arizona. Now FBI documents may offer a surprise twist in the vanishing of Job Wallace.
Severe Modulation in Feedwater-Control Valves Reveals Need for Periodic Calibration
Some combined-cycle plants have two feedwater-control valves: a small startup valve with the extra cavitation-protection needed during startup and low-load operations, and a larger main valve with the high flow-capacity needed during full-load ops. This design is intended to yield a longer service life of these valves. However, as the plant ages, this design also can yield a severe modulation, or “hunting,” in these valves.
At one 10-year-old combined-cycle plant, the two feedwater-control valves started hunting violently, eventually causing a loud boom.
The entire feedwater-piping system lurched, nearly out of its pipe rack. That startled everyone in the plant, and prompted the control room operator to hit his shutdown switch, and put in a trouble call to the maintenance shop. The maintenance technician grabbed his tool bag, went to the feedwater-control station, and began troubleshooting. He noted in his logbook that the incident had occurred shortly after a plant startup, just as the feedwater-control logic was transitioning from the startup valve to the main valve.…
Coal Silo Failures Reveal the Need for NDE Inspection
In July 2016, a coal silo collapsed at an Indiana power plant. The root cause was identified as cracking of the cone-to-skirt weld. Warnings to inspect this vulnerable weld were published widely in conference proceedings and trade journal articles. Nevertheless, coal silos continue to fail at an alarming rate (Figure 1), which suggests that the needed inspections weren’t completed by all power producers.
 |
| 1. Recent failures of cone-to-skirt welds on large coal silos point to the need for ongoing inspections. Courtesy: Joe W. Frey Engineering Associates, LLC |
If you have any of these suspended cone silos (Figure 2) in your plant and are not yet doing non-destructive evaluation (NDE) inspections of their cone-to-skirt welds, then you need to start today.
 |
| 2. Coal silos like this need our immediate attention! Courtesy: Joe W. Frey Engineering Associates, LLC |
Granted, this particular design is a real challenge to inspect, because the silo’s liner seals over the galvanic cell (in layman’s terms, a corrosion sandwich) that is created at the union of the stainless-steel liner and the carbon-steel structure.…
Kemper, Now Slated to Start in Late June, Will Need Costly Post In-Service Improvement Projects
Mississippi Power’s Kemper County integrated gasification combined cycle (IGCC) project is now expected to be in service by the end of June, but the company expects it will need post in-service improvements. It also said timing of when it will file a case to address the recovery of costs not currently reflected in rates is uncertain.
The Southern Co. subsidiary said on June 5 that it filed a rate plan with the Mississippi Public Service Commission (MPSC) that would allow current rates for recovery of portions of the Kemper project’s existing combined cycle gas turbine (CCGT) plant to remain in place. If approved, that filing will not increase customer bills, it said.
It added, however, that discussions with the MPSC continue on the status of the project and the nature and timing of a rate filing to address recovery of the remainder of the Kemper project costs, which includes its gasification component.
Mississippi Power wants a timely resolution of such a filing, which will likely require a settlement between the company and the Mississippi Public Utilities staff as well as other parties.…