7F BEST PRACTICES: Calhoun

Cardox-tank double relief valves facilitate testing, maintenance

Challenge. Relief valves for the Cardox tank were piped directly into the tank. If there were an issue with either of the relief valves sticking, the tank would have to be emptied prior to doing any work. The tank also had to be emptied to test the relief valves.

Solution. Staff worked with a vendor to make a “T” piping rig with a go/no-go switching valve so relief valves can be tested without removing the CO2 (photo).

Results. Testing is accomplished by swapping the valve and removing the offline valve. Also, the relief valves have frozen open when tank is venting, and we were able to swap it over to the standby valve to isolate. All of the above prevents either loss of CO2 or additional budgeting for vendor to remove CO2 tanks for testing.

Project participant: Mike Carter

CEMS backup A/C insert

Challenge. CEMS shacks only have one air-conditioning (A/C) unit. Every other critical A/C-cooled compartment onsite has redundant units. Plant has failed an A/C unit in the CEMS and had no back up to keep critical equipment cool.

Solution. Install an insert into the side of the building capable of holding a “window” A/C unit. Also install an additional receptacle with its own breaker outside of the distribution panel. When not in use, an insulated manway will be in place.

Results. Any A/C failures in the CEMS have not been a problem. The “window” unit can keep the shack cool until repairs can be made.

Project participant: Robin Fletcher

Calhoun Power

Owned by East Alabama Generating LLC
Operated by Consolidated Asset Management Services
748-MW, dual-fuel, four-unit simple cycle located in Eastaboga, Ala.

Plant manager: Mike Carter