- Table W-4A to Subpart W of Part 98—Default Total Hydrocarbon Leaker Emission Factors for Underground Natural Gas Storage
| Underground natural gas storage | Emission factor
(scf/hour/component) | If you survey using any of the methods in § 98.234(a)(1)
through (6) | If you survey using Method 21 as
specified in § 98.234(a)(7) | Valve 1 | 14.84 | 9.51 | Connector (other) | 5.59 | 3.58 | Open-Ended Line | 17.27 | 11.07 | Pressure Relief Valve | 39.66 | 25.42 | Meter and Instrument | 19.33 | 12.39 | Other 2 | 4.1 | 2.63 | Valve 1 | 4.5 | 3.2 | Connector (other than flanges) | 1.2 | 0.7 | Flange | 3.8 | 2.0 | Open-Ended Line | 2.5 | 1.7 | Pressure Relief Valve | 4.1 | 2.5 | Other 2 | 4.1 | 2.5 |
|---|
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(f)(6) and (8).