The Heating Plant staff in May plans to conduct required maintenance on the University’s central boiler plant and one of the main distribution lines.
Illinois State’s central boiler plant produces steam for use throughout the campus. This plant is rated to produce 380,000 pounds of steam per hour at full capacity. The peak load occurs during extremely cold winter weather and totals approximately half of the plant’s capacity. The plant’s total heating capacity is comparable to approximately 4,500 residential furnaces. The steam produced by this plant is used primarily for heating and humidification but it also is has various other applications including:
- Cooking equipment heat
- Domestic hot water heat
- Heat for swimming pool water
- Heat for dye pots used for dying costumes at Centennial East
- Heat for science equipment including the cage washer and sterilization equipment
(In the past the system provided steam to power air conditioning chillers, but as of last year all of our chillers run on electricity.)
Over the last five years we have made improvements to the plant that have greatly reduced the equipment that can only be repaired when the entire plant is down. While we can work on the vast majority of our steam and distribution systems without shutting down the plant, we still have various items that do require a full shutdown for repairs.
For 2013 we are planning to conduct required maintenance for the plant and one of the main distribution lines. During this shutdown we are going to replace three of the main boiler steam shutoff valves with newer more reliable valves. These valves can only be fixed or replaced when the entire plant is shut down since they separate the boiler from the main steam supply line which is common to all boilers and the distribution lines. By installing these more reliable valves, we will minimize the chance of a valve failure in the future requiring a system shutdown for repair or replacement.
In addition to the three main boiler shutoff valves, we are also working on valves between the main steam supply line and the distribution legs that carry the steam throughout campus. As with the main boiler valves, these can only be repaired when the entire plant is shut down. At left, a picture of one of the valves to a distribution line that is being replaced.
Finally, we are replacing a valve in the system that supplies feedwater to the boilers. While we have increased the redundancy of this system, this valve still can only be repaired when the feedwater system is shut down; since we need feedwater to operate the boilers, the replacement of this valve requires a full plant shutdown. As with the others, we are installing a more reliable style of valve which should reduce the need for future maintenance.
In addition to the full campus outage there is also additional work required on one of the main steam distribution lines. The line to be repaired supplies buildings on the west and northwest side of campus. Distribution lines have numerous components that can only be replaced or repaired when the steam is shut down. We try to shut down one of the four main distribution lines each year to conduct this required maintenance. For this outage we will be repairing or replacing several valves that isolate the main steam supply line from the buildings.
The intent of this scheduled shutdown is to complete numerous maintenance items during a single time period that causes the minimum disruption to the campus community. By getting this maintenance done in this manner we minimize the times when we have to have unscheduled shutdowns to make emergency repairs. The Heating Plant staff strives to be proactive to avoid this type of inconvenience.
The full plant shutdown is scheduled from Sunday, May 12, through Tuesday, May 14. The main steam distribution line serving buildings on the west and northwest side of campus will continue for two additional days until Thursday, May 16. The Heating Plant staff has worked with our campus partners in identifying these dates.