40 CFR Part 86, Appendix IX to Part 86 - Experimentally Determining the R-Factor for Bench Aging Durability Procedures

Status message

There is 1 Update appearing in the Federal Register for 40 CFR Part 86. View below or at eCFR (GPOAccess)
View PDF at GPOPt. 86, App. IX
Appendix IX to Part 86—Experimentally Determining the R-Factor for Bench Aging Durability Procedures
The R-Factor is the catalyst thermal reactivity coefficient used in the bench aging time (BAT) equation [Ref. § 86.1826-08(d)(3)]. Manufacturers may determine the value of R experimentally using the following procedures.
1. Using the applicable bench cycle and aging bench hardware, age several catalysts (minimum of 3 of the same catalyst design) at different control temperatures between the normal operating temperature and the damage limit temperature. Measure emissions (or catalyst inefficiency (1-catalyst efficiency)) for each constituent. Assure that the final testing yields data between one- and two-times the standard.
2. Estimate the value of R and calculate the effective reference temperature (Tr) for the bench aging cycle for each control temperature according to the procedure described in § 86.1826-08(d)(4).
3. Plot emissions (or catalyst inefficiency) versus aging time for each catalyst. Calculate the least-squared best-fit line through the data. For the data set to be useful for this purpose the data should have an approximately common intercept between 0 and 4000 miles. See the following graph for an example.
4. Calculate the slope of the best-fit line for each aging temperature.
5. Plot the natural log (ln) of the slope of each best-fit line (determined in step 4) along the vertical axis, versus the inverse of aging temperature (1/(aging temperature, deg K)) along the horizontal axis, Calculate the least-squared best-fit lines through the data. The slope of the line is the R-factor. See the following graph for an example.
6. Compare the R-factor to the initial value that was used in Step 2. If the calculated R-factor differs from the initial value by more than 5%, choose a new R-factor that is between the initial and calculated values, then repeat Steps 2-6 to derive a new R-factor. Repeat this process until the calculated R-factor is within 5% of the initially assumed R-factor.
7. Compare the R-factor determined separately for each constituent. Use the lowest R-factor (worst case) for the BAT equation.
[71 FR 2837, Jan. 17, 2006]

Title 40 published on 2015-07-01.

The following are only the Rules published in the Federal Register after the published date of Title 40.

For a complete list of all Rules, Proposed Rules, and Notices view the Rulemaking tab.

  • 2015-07-28; vol. 80 # 144 - Tuesday, July 28, 2015
    1. 80 FR 44863 - Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles—Phase 2; Notice of Public Hearings and Comment Period
      GPO FDSys: XML | Text
      DEPARTMENT OF TRANSPORTATION, ENVIRONMENTAL PROTECTION AGENCY, National Highway Traffic Safety Administration
      Notice of public hearings; extension of comment period.
      NHTSA and EPA will jointly hold a public hearing on Thursday, August 6, 2015, beginning at 9:00 a.m. local time, and a second hearing on Tuesday, August 18, 2015, beginning at 9:00 a.m. local time. EPA and NHTSA will make every effort to accommodate all speakers that arrive and register. Each hearing will continue until everyone has had a chance to speak. If you would like to present oral testimony at one of these this public hearings, please contact the person identified under FOR FURTHER INFORMATION CONTACT by August 3, 2015, for the first hearing, or by August 11, 2015, for the second hearing. In order to provide commenters 30 days after the last public hearing, the comment period for the proposal is being extended through September 17, 2015.
      40 CFR Parts 9, 22, 85, 86, 600, 1033, 1036, 1037, 1039, 1042, 1065, 1066, and 1068

Title 40 published on 2015-07-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 40 CFR Part 86 after this date.

  • 2015-09-08; vol. 80 # 173 - Tuesday, September 8, 2015
    1. 80 FR 53756 - Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles—Phase 2; Extension of Comment Period
      GPO FDSys XML | Text
      DEPARTMENT OF TRANSPORTATION, ENVIRONMENTAL PROTECTION AGENCY, National Highway Traffic Safety Administration
      Proposed rule; extension of comment period.
      The comment period for the proposed rule published July 13, 2015 (80 FR 40139) is extended. Written comments for both documents must be received on or before October 1, 2015.
      40 CFR Parts 9, 22, 85, 86, 600, 1033, 1036, 1037, 1039, 1042, 1065, 1066, and 1068