{"data":{"id":"us/40-cfr-table-30-to-subpart-g-of-part-63","jurisdiction":"us","citation":"40 CFR Table 30 to Subpart G of Part 63","heading":"Table 30 to Subpart G of Part 63—Roof Fitting Loss Factors, KFa, KFb, and m, a and Typical Number of Fittings, NT","body":"Fitting type and construction details Loss factors b Typical number of fittings, NT\nKFa (lb-mole/yr) KFb (lb-mole/[mi/hr]m-yr) m (dimensionless)\nAccess hatch (24-in-diameter well) 1.\nBolted cover, gasketed 0 0 c 0\nUnbolted cover, ungasketed 2.7 7.1 1.0\nUnbolted cover, gasketed 2.9 0.41 1.0\nUnslotted guide-pole well (8-in-diameter unslotted pole, 21-in-diameter well) 1.\nUngasketed sliding cover 0 67 c 0.98\nGasketed sliding cover 0 3.0 1.4\nSlotted guide-pole/sample well (8-in-diameter unslotted pole, 21-in-diameter well) (d).\nUngasketed sliding cover, without float 0 310 1.2\nUngasketed sliding cover, with float 0 29 2.0\nGasketed sliding cover, without float 0 260 1.2\nGasketed sliding cover, with float 0 8.5 1.4\nGauge-float well (20-inch diameter) 1.\nUnbolted cover, ungasketed 2.3 5.9 c 1.0\nUnbolted cover, gasketed 2.4 0.34 1.0\nBolted cover, gasketed 0 0 0\nGauge-hatch/sample well (8-inch diameter) 1.\nWeighted mechanical actuation, gasketed 0.95 0.14 c 1.0\nWeighted mechanical actuation, ungasketed 0.91 2.4 1.0\nVacuum breaker (10-in-diameter well) NF6 (Table 31).\nWeighted mechanical actuation, gasketed 1.2 0.17 c 1.0\nWeighted mechanical actuation, ungasketed 1.2 3.0 1.0\nRoof drain (3-in-diameter) NF7 (Table 31).\nOpen 0 7.0 e 1.4 NF8 (Table 32 f).\n90 percent closed 0.51 0.81 1.0\nRoof leg (3-in-diameter) NF8 (Table 32 f).\nAdjustable, pontoon area 1.5 0.20 c 1.0\nAdjustable, center area 0.25 0.067 c 1.0\nAdjustable, double-deck roofs 0.25 0.067 1.0\nFixed 0 0 0\nRoof leg (21⁄2-in-diameter) NF8 (Table 32 f).\nAdjustable, pontoon area 1.7 0 0\nAdjustable, center area 0.41 0 0\nAdjustable, double-deck roofs 0.41 0 0\nFixed 0 0 0\nRim vent (6-in-diameter) 1 g.\nWeighted mechanical actuation, gasketed 0.71 0.10 c 1.0\nWeighted mechanical actuation, ungasketed 0.68 1.8 1.0\na The roof fitting loss factors, KFa, KFb, and m, may only be used for wind speeds from 2 to 15 miles per hour.\nb Unit abbreviations are as follows: lb = pound; mi = miles; hr = hour; yr = year.\nc If no specific information is available, this value can be assumed to represent the most common or typical roof fittings currently in use.\nd A slotted guide-pole/sample well is an optional fitting and is not typically used.\ne Roof drains that drain excess rainwater into the product are not used on pontoon floating roofs. They are, however, used on double-deck floating roofs and are typically left open.\nf The most common roof leg diameter is 3 inches. The loss factors for 21⁄2-inch diameter roof legs are provided for use if this smaller size roof is used on a particular floating roof.\ng Rim vents are used only with mechanical-shoe primary seals.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 63—NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES","Subpart G—National Emission Standards for Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"330d20508737c1ff22fe85e09339edeae6791cced10466b6030e32796277159c","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-table-29-to-subpart-g-of-part-63","next":"us/40-cfr-table-31-to-subpart-g-of-part-63"},"notice":"GroundRules: Original legal text. Not legal advice."}