40 CFR Part 98, Table W-4
| Equipment components | Emission factor(scf total hydrocarbon/hour/component) |
|---|---|
| If you survey using Method 21 as specified in § 98.234(a)(2)(i) | If you survey using Method 21 as specified in § 98.234(a)(2)(ii) | If you survey using any of the methods in § 98.234(a)(1), (3), or (5) |
Leaker Emission Factors—Onshore Natural Gas Processing, Onshore Natural Gas Transmission Compression—Compressor Components, Gas Service
| Valve 1 | 14.84 | 9.51 | 24.2 |
|---|---|---|---|
| Connector | 5.59 | 3.58 | 9.13 |
| Open-Ended Line | 17.27 | 11.07 | 28.2 |
| Pressure Relief Valve | 39.66 | 25.42 | 64.8 |
| Meter | 19.33 | 12.39 | 31.6 |
| Other 2 | 4.1 | 2.63 | 6.7 |
Leaker Emission Factors—Onshore Natural Gas Processing, Onshore Natural Gas Transmission Compression—Non-Compressor Components, Gas Service
| Valve 1 | 6.42 | 4.12 | 10.5 |
|---|---|---|---|
| Connector | 5.71 | 3.66 | 9.3 |
| Open-Ended Line | 11.27 | 7.22 | 18.4 |
| Pressure Relief Valve | 2.01 | 1.29 | 3.28 |
| Meter | 2.93 | 1.88 | 4.79 |
| Other 2 | 4.1 | 2.63 | 6.7 |
Leaker Emission Factors—Underground Natural Gas Storage—Storage Station, Gas Service
| Valve 1 | 14.84 | 9.51 | 24.2 |
|---|---|---|---|
| Connector (other) | 5.59 | 3.58 | 9.13 |
| Open-Ended Line | 17.27 | 11.07 | 28.2 |
| Pressure Relief Valve | 39.66 | 25.42 | 64.8 |
| Meter and Instrument | 19.33 | 12.39 | 31.6 |
| Other 2 | 4.1 | 2.63 | 6.7 |
Leaker Emission Factors—Underground Natural Gas Storage—Storage Wellheads, Gas Service
| Valve 1 | 4.5 | 3.2 | 7.35 |
|---|---|---|---|
| Connector (other than flanges) | 1.2 | 0.7 | 1.96 |
| Flange | 3.8 | 2 | 6.21 |
| Open-Ended Line | 2.5 | 1.7 | 4.08 |
| Pressure Relief Valve | 4.1 | 2.5 | 6.7 |
| Other 2 | 4.1 | 2.5 | 6.70 |
1 Valves include control valves, block valves and regulator valves.
2 Other includes any potential equipment leak emission point in gas service that is not specifically listed in this table, as specified in § 98.232(d)(7) for onshore natural gas processing, § 98.232(e)(8) for onshore natural gas transmission compression, and as specified in § 98.232(f)(6) and (8) for underground natural gas storage.
[89 FR 42325, May 14, 2024]