The dataset ranks 97 assignees across 244 records, and the field is concentrated at the top: the leading assignee holds 23 records, more than double the fifth-place count of 9. The top five assignees combined account for 30.3% of all 244 records in scope, while the top ten reach 46.7%. Beyond that, filings spread thinly across dozens of companies and individual inventors, each holding only a handful of records, which is typical for infrastructure hardware tied to specific terminal operators and engineering contractors.

Filings peaked at 30 records in 2021 and fell to 1 by 2024, a -97% change over three years according to the tracked data. That kind of drop can reflect a design generation reaching maturity, a shift of engineering attention to adjacent systems, or simply fewer new entrants filing around an established rim-seal and floating-roof architecture. It is worth noting that 2025 and 2026 figures are still incomplete because publication typically lags filing by about 18 months, so the full extent of any rebound or continued decline is not yet visible in this data.

The dominant class is B65D, containers and packaging, appearing on 61.9% of the 244 records in scope, which reflects that most filings claim some structural aspect of the tank itself. Smaller but distinct clusters sit in G01F (flow, level and volume measuring, 7.4%), G01M (structural testing, 7.0%), B08B (cleaning, 5.7%), F16L (pipe fittings, 5.3%), G01N (material analysis, 5.3%), C07C (acyclic compounds, 4.9%) and A62C (fire-fighting, 4.1%). Because a single record can carry multiple IPC codes, these percentages add up to more than 100% of the record total, and they should be read as overlapping coverage rather than a strict breakdown.

US6164479A, granted to Ultra Flota Corp. in 2000, claims an internal floating roof tank with a peripheral sealing ring of shoes held against the tank wall by spring-loaded or otherwise resilient horizontally-travelling members, with a flexible cover over the shoe-to-deck gap to limit product loss. It matters because it establishes a specific mechanical approach to rim sealing that keeps the roof centred without vertical shoe travel, a design choice that later floating-roof filings in this dataset continue to reference. Anyone designing a new rim seal system should check this claim's mechanical linkage details closely before finalising a shoe-and-spring architecture.

The concentration data shows most claim density sitting in B65D container structure and rim-seal hardware, while adjacent branches such as annular plate corrosion monitoring, tank bottom settlement sensing, and breathing-loss capture systems carry comparatively few of the 244 records. These branches touch real operational problems — corrosion-driven tank failures and evaporation losses are well documented industry concerns — but they are not yet heavily claimed in this corpus. A team with a specific sensing or capture mechanism in one of these areas is more likely to find open claim space there than in another rim-seal or shell-course filing.