Measure Overview
A process boiler is a type of boiler with a capacity (rated maximum input) of 300,000 British Thermal Units per hour (Btu/h) or more that serves loads other than space conditioning and service water heating related to human occupancy.
This proposed code change would require all newly installed process boilers with capacities at or above 10 million Btu/h (MMBtu/h) that are served by a pressurized deaerator to recover and route flash steam from blowdown to the deaerator or another steam load. The requirement would apply to all new process boilers, including replacement boilers and boilers in additions to existing facilities.
There are two proposed exceptions to the requirement:
- Boiler systems where high-pressure condensate is returned to the deaerator without being flashed (dropped to atmospheric pressure).
- Boiler systems where the linear distance from the boiler to the serving deaerator is greater than or equal to 100 feet.
All boilers qualifying for one of the exceptions must indicate either the installation of a pressurized condensate return system or the linear distance from the boiler to the serving deaerator in the construction documents according to the exception they are pursuing.
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This measure page will be updated as the 2028 code cycle progresses. For questions or suggestions, email [email protected]. Please include the measure name in the subject line.
Scope of Proposed Code Change
| Building Type(s) | Construction Type(s) | Type of Change | Updates to Compliance Software | Third Party Verification |
| Nonresidential | New construction, additions, alterations | Mandatory | No updates | No changes to third party verification |
Justification for Proposed Change
When steam condensate is dropped to a pressure lower than its saturation (boiling-point) pressure, a fraction of it vaporizes, or flashes, into what is known as “flash steam.” Most sites vent flash steam to the atmosphere, resulting in significant fuel, water, and chemical losses. Many steam system design options are available to recover and repurpose flash steam for useful heating to serve low-pressure loads, such as the deaerator, instead of using high-pressure live boiler steam for the same purpose. Flash vessels capture flash steam and allow it to be piped to various applications.
Flash steam recovery has been listed in Department of Energy (DOE) literature as a best practice since at least the early 2000s, and the DOE has five steam tip-sheets for different flash steam recovery methods. This proposed code change originated from discussions with California-based consulting engineers from strategic energy management programs and the DOE Industrial Assessment Center program.
To the Statewide CASE Team’s knowledge, flash steam recovery requirements have not been proposed in previous code cycles. In 2013, Title 24 first adopted requirements for process boilers. In 2022, Title 24 adopted requirements for strainers and fault detection and diagnostics in steam trap assemblies.
Requiring flash steam recovery would save fuel, water, and chemicals. This measure is expected to save approximately 1% of baseline boiler system fuel use. In addition, the requirement would reduce water and the associated chemicals used for water treatment, as the flash steam is no longer vented to the atmosphere and its condensate can be returned to the boiler plant. Ancillary benefits include improved plant safety and improved public perception through reduction of steam plumes.
Relevant Documents
Round One Utility-Sponsored Stakeholder Meeting Materials
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The Statewide CASE Team values input from all stakeholders engaged in the Title 24, Part 6 code change process. We encourage the open exchange of code change comments and concerns.