66.17 Processing Facilities
- The process vessel shall be closed to the room in which it is located and vented to the outside of the building.
- If the vessel needs to be opened to add ingredients, the room ventilation shall meet the requirements of 66.17.11 and the process heating controls will be interlocked with the ventilation such that the process heat will shut down if the ventilation fails or is turned off.
- The process vessel shall be equipped with an excess temperature control set to limit excessive heating of the liquid and the subsequent release of vapors.
- If a heat transfer medium is used to heat the liquid and the heat transfer fluid can heat the liquid to its boiling point on failure of the process and excess temperature heat controls, a redundant excess temperature control shall be provided.
- In accordance with Table 220.127.116.11
- In accordance with an engineering evaluation of the process, followed by application of sound fire protection and process engineering principles
|Vessel Maximum Operating Liquid Capacity (gal)||Minimum Distance (ft)|
|From Property Line that Is or Can Be Built upon, Including Opposite Side of Public Way||From Nearest Side of Any Public Way or from Nearest Important Building on Same Property that Is Not an Integral Part of the Process|
|Stable Liquid Emergency Relief*||Unstable Liquid Emergency Relief*||Stable Liquid Emergency Relief*||Unstable Liquid Emergency Relief*|
|Not Over 2.5 psi||Over 2.5 psi||Not Over 2.5 psi||Over 2.5 psi||Not Over 2.5 psi||Over 2.5 psi||Not Over 2.5 psi||Over 2.5 psi|
|275 or less||5||25||50||100||5||25||50||100|
|276 to 750||10||25||50||100||5||25||50||100|
|751 to 12,000||15||25||50||100||5||25||50||100|
|12,001 to 30,000||20||30||50||100||5||25||50||100|
|30,001 to 50,000||30||45||75||120||10||25||50||100|
|50,001 to 100,000||50||75||125||200||15||25||50||100|
For SI units, 1 gal = 3.8 L; 1 ft = 0.3 m; 1 psi = a gauge pressure of 6.9 kPa.
Note: Double all of above distances where protection for exposures is not provided.
*Gauge pressure. [30: Table 17.4.3]
- 25 ft (7.6 m) clear spacing
- A wall having a fire resistance rating of not less than 2 hours and explosion resistance consistent with the expected hazard
|Liquid Class||Minimum Type of Construction*||Minimum Separation Distance (ft)|
|To Street, Alley, or Public Way||To Adjacent Property Line that Is or Can Be Built Upon|
|Class I liquids; unstable liquids of any class; liquids of any class heated above their flash points†||II (222)||5||10|
|Class II||II (111)||5||10|
|Class III||II (000)||5||10|
For SI units, 1 ft = 0.3 m.
Note: Distances apply to properties that have protection for exposures, as defined in this code. If there are exposures for which protection does not exist, the distances should be doubled, in accordance with 18.104.22.168.
*Construction types are defined in NFPA 220, Standard on Types of Building Construction. [30: Table 17.6.1]
- Drainage to a safe location to prevent liquids from accumulating under vessels or equipment or around load- bearing supports
- Fire-resistive construction
- Fire-resistant protective coatings or systems
- Water spray systems designed and installed in accordance with NFPA 15
- Other alternate means acceptable to the AHJ