Appendix B19
Notes on Rules
Diagrams B19

Appendix B19 - Notes on Rules

The notes and diagrams in this Appendix are for information and clarification purposes only and apply to the following rules:


Rule

 Note
19-000
Scope
requirement was added or amended		 Persons using this Code should be aware of other regulatory requirements such as in the areas of energy, occupational health & safety and environment.

See also Appendix J and notes on rules 18-000, 18-002 and 18-006 in Appendix B of the CEC.

Where installations are not covered by this Code [19-000(2)(a) to (d)], sound engineering principles should be applied to determine if an installation should be classified in accordance with Rule 18-004 and 18-006 of the CEC.
19-052 This rule allows for additional situations not specifically addressed in the CEC.

Users should give careful consideration to electrical installations where adverse conditions expose electrical equipment to a corrosive environment or to excessive moisture. The nature of activity at oil well servicing or drilling operations (i.e., equipment subject to splashing or direct streams of water), may require the use of "Type 4" enclosures, "type TE" motors or equivalent. For additional information on IEC Ingress Protection (I.P.) designations, refer to IEC Standard 529 and CEC Appendix B note to rule 18-106(5).
19-052(1) The use of flexible cord at drilling and servicing sites or oil and gas wells is intended to recognize situations where fixed wiring methods cannot provide the necessary degree of movement for fixed or mobile electrical equipment required to be frequently moved. It is not intended to be a substitute for fixed wiring. Excessive length, quantities and use of flexible cord or portable power cable is to be avoided.
19-052(4) The use of a combination motor controller as service equipment for a single oil well pump may be appropriate where the utility has no meter or where the supply service requirements of the CEC permit "hot" metering installations. The supply authority should be consulted for metering requirements.
19-100 This rule recognizes the expertise of an engineer in classifying Oil and Gas facilities. The engineer must be experienced in determining area classifications for hazardous locations as outlined in Rule 18-006 of the CEC and knowledgeable in using industry-recognized standards and recommended practices. (See notes on rule 18-006 in Appendix B of the CEC.)

Without engineering involvement, the requirements for classifying hazardous locations in rules 19-102 to 19-108 are the minimum requirements. When applying these minimum requirements, users are advised of their responsibility to ensure that they are adequate for the installation. Circumstances may dictate the need to exceed these rules to achieve an acceptable level of safety performance.
19-102
19-104
19-106
19-108		 Rule 19-102 outlines area classifications for various installations that can be common to all types of oil and gas facilities. Rule 19-104 to 19-108 outline additional or supplemental area classifications for situations encountered at specific installations.

The term "flammable" used throughout these rules with the words liquids, gases, and vapours should be taken in the context of the likelihood for these substances to create an explosive gas atmosphere. For more information on flammable liquids, gases and vapours see American Petroleum Institute RP500 & RP505 and NFPA Standard No. 30.

To aid in the application of these rules, see the Diagrams B19, 1 to 16.
19-102
(1)(b),(c),(d)
(2)(e),(f),(g)
(3)(f),(g),(h)		 To differentiate between different types of vents, the term is divided into three distinct categories: process equipment vents (e.g., pressure relief valves, blow-downs, etc.), instrument and control device vents (e.g., vents from gas actuated control devices, gas chromatograph vents, etc.) and atmospheric vents (e.g., building ridge vents, roof vents, tank vents, etc.). See American Petroleum Institute RP500 & RP505 for further information.
19-102(2)(a) When we interpret the requirement of roof ventilators for shed type buildings or enclosures, we should take into consideration the shape of the roof. In contrast to a gabled roof, flat roofs would not normally allow a significant accumulation of lighter than-air-gases unless the fascia or roof edge prevented those gases from dispersing.

19-102(3)(d) When locating enclosures or buildings (with electrical equipment intended for non-hazardous locations) adjacent to a classified area, we should consider the boundary of the classified area as being an arbitrary line. Even though the building or enclosure does not infringe upon the classified area, care should be taken to avoid locating them in close proximity to these areas, unless they have a vapour-tight barrier. American Petroleum Institute RP500 and RP505 define vapour-tight barrier as a barrier that will not allow the passage of significant quantities of gas or vapour at atmospheric pressure.
19-104 Rule 19-104(d) does not anticipate situations where the "doghouse" forms part of the enclosure surrounding the rig floor. When the rig floor will be "tarped-in" or otherwise enclosed with the doghouse forming part of the enclosure, professional engineering involvement will be needed to determine required measures for maintaining a non-hazardous classification in the "doghouse".