Flare & Vapor Control Systems for Pipelines, Truck Loading, and Bulk Terminals

40 CFR Part 63 Subpart BBBBBB requires covered bulk gasoline terminals to direct displacement vapors from loading operations to a vapor balance system, vapor recovery unit, or combustion control device achieving at least 95% VOC reduction. The rule requires annual performance testing or continuous monitoring to demonstrate ongoing compliance with the DRE requirement. Subpart BBBBBB applies to terminals with throughput above 76,000 liters per day of gasoline, which covers virtually all commercial bulk terminals in the US. HPS enclosed combustors are designed to meet the DRE requirement with engineering documentation for the initial permit application and ongoing compliance recordkeeping.

NFPA 30 and good engineering practice require deflagration flame arrestors in vapor collection headers at gasoline and flammable liquid terminals. The flame arrestor prevents propagation of a flame front back through the collection piping from the combustion device to the vapor source (the truck compartment or storage tank).

Multi-product terminals must size the combustor for the worst-case scenario for each relevant parameter. For flow rate, size for the maximum simultaneous loading scenario regardless of product. For BTU content, confirm the combustor will operate stably on the lowest-BTU product in the slate: diesel displacement vapors are much leaner than gasoline vapors and may fall below the minimum NHV for stable unaided combustion.

NSPS Subpart Kb applies to fixed roof storage tanks between 19,800 and 40,000 gallons constructed after July 23, 1984 that store VOL at vapor pressure above 0.75 psia. If your tanks meet those thresholds, you need either a floating roof or a control device (VRU or combustor) achieving 95% VOC emission reduction.

Liquid carryover in a vapor collection header is a real concern at crude oil and condensate terminals, particularly during initial blowdown when liquid slugs may enter the header.

NFPA 30 provides minimum separation distances between ignition sources (including flares and combustors) and flammable liquid storage tanks, pump islands, and loading racks. For a combustion device with an active flame, the required distance from the nearest Class I liquid tank or loading position is typically 50 feet, but this varies with tank size, product flash point, and local authority having jurisdiction interpretations.