Engineering:Fixed roof tank
A fixed roof tank is a type of storage tank, used to store liquids, consisting of a cone- or dome-shaped roof that is permanently affixed to a cylindrical shell. Newer storage tanks are typically fully welded and designed to be both liquid- and vapor-tight. Older tanks, however, are often riveted or bolted, and are not vapor tight. A breather valve (pressure-vacuum valve), commonly installed on many fixed roof tanks, allows the tank to operate at a slight internal pressure or vacuum. This valve prevents the release of vapors during very small changes in temperature, barometric pressure, or liquid level.[1] Fixed roof tanks without breather valves will generally be freely vented;[2] thus the emissions from a fixed roof tank can be non-trivial. Gauge hatches, sample wells, float gauges, and roof manholes provide accessibility to these tanks, and also act as potential sources of volatile emissions.[3][4]
Applications
Storage tanks in general, and fixed roof tanks in particular, containing organic liquids can be found in many industries, including:
- petroleum production and refining
- petrochemical and chemical manufacturing
- bulk storage and transfer operations
- other industries consuming organic liquids[2]
Fixed roof tanks are typically used with products that have relatively low volatilities and flash points.[5] Using a fixed roof tank to store a product with high volatility can lead to product losses as vapors escape the enclosure.[6]
See also
References
- ↑ BNH Gas Tanks. "Fixed Roof Tank". http://www.fixedrooftank.com/. Retrieved 5 December 2015.
- ↑ 2.0 2.1 South Coast Air Quality Management District. "Supplemental Instructions For Liquid Organic Storage Tanks". http://www.aqmd.gov/docs/default-source/planning/annual-emission-reporting/supplemental-instructions-for-liquid-organic-storage-tanks.pdf?sfvrsn=2. Retrieved 5 December 2015.
- ↑ Werner Sölken. "Explore the World of Piping - Introduction to Storage Tanks". http://www.wermac.org/equipment/storage_tanks_vessels_general.html. Retrieved 5 December 2015.
- ↑ USA Environmental Protection Agency. "Alternative Control Techniques Document:Volatile Organic Liquid Storage in Floating and Fixed Roof Tanks". http://www3.epa.gov/ozonepollution/SIPToolkit/ctg_act/199401_voc_epa453_r-94-001_liquid_storage_roof_tanks.pdf. Retrieved 5 December 2015.
- ↑ Buckeye Fire Equipment. "Storage Tanks: Fixed or Semi-fixed Systems". http://buckeyefire.com/pdfs/foampdfs/storage/fixed.pdf. Retrieved 5 December 2015.
- ↑ ISEC Company. "Fixed Roof Tank". https://www.youtube.com/watch?v=a_3kOcjLBu4.
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