In partnership with the State Energy Office, NC State performed a steam trap survey of the five Central Utility Plants and many of the connected buildings. The goal of the survey was to determine the status of the steam distribution system, and to correct defects when identified.
Steam traps are devices used to remove condensate from live steam, which allows the system to operate more efficiently.
The three important functions of a steam trap include:
- Discharging condensate as soon as it is formed,
- minimizing steam loss, and
- its ability to discharge air and other non-condensable gases.
The steam trap fails if any of the above functions are defective. Trap failure represents a dollar amount of energy lost by the university. Out of 934 traps surveyed, 133 traps were found to be defective, or approximately 14% failure rate. This defect rate represents a significant loss of stream from the distribution system, and an annual loss of approximately $207,917 to the university. The simple return on investment to replace or repair the defective traps is less than six months.
As a result of the survey, the university has launched a Steam Trap Maintenance Program to reduce the defect rate and associated energy loss. To achieve an efficient steam trap management system, the district plants have taken proactive measures to replace faulty traps, remove bypass valves, and install proper drip legs to collect condensates. Based on the root analysis of the existing steam trap design failures, each district plant will increase its performance and reliability by selecting the proper steam trap design. The goal of the Steam Trap Maintenance Program is to reduce the failure rate of the steam trap population to less than 3%.