External Floating Roof Seals - Primary Seals

Comparison Chart

HMT offers a multiple primary seal options for external floating roof tanks. Each seal is customized to fit to the tank to ensure non-gapping performance, long life and safe operation. External primary seals include a variety of configurations, component sizes and material options to handle any application and stored product. Shoe seals also include wax-scraper options.

Compare HMT’s External Floating Roof Primary Seals

Contact an HMT sales rep to discuss which one is right for your application.

External Floating Roof Seals - Primary Seals

Liquid Mounted
(Foam or Liquid Filled)

(Shoe seal with typical carbon steel hangers)

Single Arm Support
(Shoe seal with single arm pusher)

Scissor Shoe
(Shoe seal with independent pushers)


(Heavy Duty  / Extreme Weather)

Emissions throughout 10 year life span Not Recommended Good Good Excellent Best / BATǂ  Excellent
Conforms to shell roundness anomalies Average Average Average Best Best Best
Chemical, Corrosion & UV Resistance Average Good Excellent Best Best
Shoe stays level as rim space changes N/A

Pressure distribution on shoe N/A
6 points 3-6 points 10 points Uniform Pressure / Full Contact 4 points
Roof centering capabilities / dampen movement Not Recommended Good Average Best Best Best
Abrasion resistance Not Recommended Best Best Best Best Best
Life expectancy Not Recommended Good Good Best Best Excellent
Applicable guidelines API 650 API 650 API 650 API 650 EEMUA 159 (-X+3X), API 650, EN 14015 API 650, EEMUA 159, EN 14016
Capable of handling waxy shell residue N/A with wax scraper with wax scraper with wax scraper with wax scraper tested wax scraper**
Available in riveted tank option N/A

*State of the art technology

**Link to test documents

ǂ Capable of gas tight (TÜV) certification