SECTION 4.8  PROCESS PLANTS

Subsection 4.8.1.  Application

Application

4.8.1.1.  (1)  Except as provided in Sentence (2), this Section applies to those process plants, including refineries, which contain industrial processes involving flammable liquids or combustible liquids.

(2)  This Section does not apply to distilleries covered in Section 4.9.

Subsection 4.8.2.  Outdoor Processing Equipment

Location

4.8.2.1.  (1)  The location of outdoor processing equipment in process plants shall be based on its flammable liquid and combustible liquid capacity as described in Sentences (2) to (4).

(2)  Except as provided in Sentence (4), outdoor processing equipment having emergency relief venting and a working pressure of not more than 17 kPa (gauge) shall be separated from property lines and buildings on the same property by distances

(a)   equal to those in Table 4.3.2.A. for stable liquids, and
(b)   2.5 times those in Table 4.3.2.A. for unstable liquids.

    (3)  Except as provided in Sentence (4), outdoor processing equipment having emergency relief venting and a working pressure more than 17 kPa (gauge) shall be separated from property lines and buildings on the same property by distances

(a)   1.5 times those in Table 4.3.2.A. for stable liquids, and
(b)   four times those in Table 4.3.2.A. for unstable liquids.

    (4)  Where protection is not provided against fires or explosions in processing equipment, the distances in Sentences (2) and (3) shall be doubled.

Subsection 4.8.3.  Processing Buildings

Explosion venting

4.8.3.1.  Except as provided in Article 4.8.4.2., where Class IA liquids or unstable liquids are processed within a room or a building, the room or building shall be designed to prevent critical structural and mechanical damage from an internal explosion in conformance with NFPA 68, “Standard on Explosion Protection by Deflagration Venting”.

Fire separations

4.8.3.2.  Areas where unstable liquids are handled or where small-scale unit chemical processes are carried out shall be separated from the remainder of the building by a fire separation having a fire-resistance rating not less than 2 h.

Basements and pits

4.8.3.3.  (1)  Except as permitted in Article 4.1.5.9., Class I liquids shall not be handled or used in basements.

(2)  Where Class I liquids are handled or used above grade within existing buildings that have basements or covered pits into which flammable vapours can travel and accumulate, such below grade areas shall be provided with mechanical ventilation designed to prevent the accumulation of flammable vapours.

(3)  The mechanical ventilation required in Sentence (2) shall be capable of exhausting at least 18 m³/h per square metre of the room area.

Ventilation

4.8.3.4.  (1)  Enclosed processing buildings handling flammable liquids or combustible liquids shall be ventilated as specified in Subsection 4.1.7.

(2)  Equipment used in a building and the ventilation of the building shall be designed so as to limit flammable vapour-air mixtures under normal operating conditions to the interior of equipment, and to not more than 1.5 m from such equipment.

Subsection 4.8.4.  Fire Prevention and Protection

Spill and vapour control

4.8.4.1.  (1)  Processing equipment shall be designed and arranged to

(a)   prevent the unintentional escape of liquids and vapours, and
(b)   minimize the quantity escaping in the event of accidental release.

    (2)  Measures to control spilled flammable liquids and combustible liquids shall be provided in conformance with Subsection 4.1.6.

Explosion protection

4.8.4.2.  (1)  Processing equipment where an explosion hazard is present shall be

(a)   designed to withstand the explosion pressure without damage to the equipment,
(b)   provided with explosion venting in conformance with NFPA 68, “Standard on Explosion Protection by Deflagration Venting”, or
(c)   provided with an explosion prevention system in conformance with NFPA 69, “Standard on Explosion Prevention Systems”.

Fire prevention and protection

4.8.4.3.  (1)  An evaluation of the fire and explosion risks shall be undertaken to consider the material properties, quantities, operating conditions, storage arrangement, transportation, process design, operating and maintenance procedures.

(2)  The evaluation in Sentence (1) shall result in the identification of measures that will minimize fires and explosions from occurring and mitigate the effects of a fire or explosion should it occur.

(3)  Measures identified in Sentence (2) shall be implemented in conformance with good engineering practices to prevent fires and explosions from occurring.

(4)  Measures identified in Sentence (2) may include but are not limited to

(a)   fire detection and alarm,
(b)   special fire suppression systems conforming to the standards identified in Sentences 6.8.1.1.(3) and (4),
(c)   sprinkler system conforming to NFPA 13, “Standard for Installation of Sprinkler Systems”,
(d)   a reliable water supply with pressure and flow rates capable of meeting the fire demands,
(e)   standpipe and hose systems connected to a reliable water supply located such that vessels, pumps and other equipment containing flammable liquids or combustible liquids can be reached with at least one hose stream,
(f)   combination nozzles capable of discharging a straight steam, water spray or fog,
(g)   hydrants or monitor nozzles installed in accordance with NFPA 24, “Standard for the Installation of Private Fire Service Mains and their Appurtenances”,
(h)   fire-proofing to protect essential equipment and controls,
(i)   methods to effect an emergency shutdown of systems, and
(j)   methods to protect equipment and structures from fire exposure.

      (5)  The evaluation and measures shall be put in writing and kept in the building for review by the Chief Fire Official.