Measure Overview
This measure would require newly constructed process steam systems and new, non-replacement process steam loads at existing facilities that meet a set of criteria to recover or reduce at least 35% of their flash steam using one or more methods such as the following:
- Recovery and reuse of flash steam from high-pressure condensate, via:
- direct reuse,
- thermal vapor recompression (TVR), or
- mechanical vapor recompression (MVR)
- Recovery and reuse of flash steam from boiler blowdown
- Implementation of a pressurized condensate return system.
Newly constructed process steam systems would qualify for the requirement if they:
- have one or more connected boilers with an input rating (capacity) of 10 MMBtu/h or greater,
- have a pressurized deaerator, and
- have a boiler design condition pressures of 100 psig or greater.
New, non-replacement process steam loads at existing facilities would qualify for the requirement if they:
- have one or more connected boilers with an input rating (capacity) of 10 MMBtu/h or greater,
- are connected to system with a pressurized deaerator,
- are served by a header that has a design condition pressure of 100 psig or greater, and
- meet the conditions in Table 1.
Table 1: Steam Load Addition Code Trigger Criteria for Existing Facilities
| Steam Flow (lb/h) | Linear Length1 (ft) less than |
| <5,000 | Exempt |
| >5,000, <7,500 | 150 |
| >7,500, <10,000 | 350 |
| >10,000, <15,000 | 500 |
| >15,000 | 1,000 |
Applications for flash steam reuse may include:
- Low-pressure steam loads
- Steam-to-hot-water heat exchangers
- Deaerator heating
- Intermediate-pressure steam loads.
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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 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, and TVR and MVR can boost the flash steam pressure if needed. Alternatively, a pressurized condensate return system can minimize flashing of condensate as it is returned to the deaerator.
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. When applied throughout typical steam systems, this measure is expected to save approximately 1% to 5% of baseline boiler system fuel use. In addition, the requirement would reduce water and sewer use 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.