Work on Flammable or Explosive Material Containers

UNB Reference Number: 7809
Authorized by: J. M. Anderson, President,
Effective Date: December 1, 1978
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Intent

To outline procedures for performing "hot work" on a container used for explosive or flammable substances.

Scope

All University personnel working on containers that are, or have been, used for explosive or flammable substances.

Procedures

  1. Where repairs or alterations which involve welding, brazing, soldering or any operation involving open flame, have to be performed on a container that is, or has been, used for explosive or flammable substances, the following precautions must be taken:
    • The substance must be removed from the container in an area free from any potential source of ignition.
    • The container must be purged in a manner which will render it free from any flammable or explosive vapors. This can be done in one or a combination of the following methods.
    • steam the container until it is free from flammable or explosive vapors
    • flush the container with warm water until it is free from flammable or explosive vapors
    • purge the container with CO2 until it is free from flammable or explosive vapors.
  2. The container shall not be deemed free from flammable or explosive vapors unless it has been tested with an explosion meter or similar instruments approved for the purpose of detecting flammable or explosive vapors and certified in writing by the employer to be free of combustible gases or vapors.
  3. A CO2 fire extinguisher must be readily available while such work is being performed.
  4. Before recharging the container must be cooled sufficiently to prevent any risk of igniting the substance.
  5. Where welding, soldering or any other application of heat to large tanks is involved.

Note: refer to the N.B. Occupational Health & Safety Act & Regulations for details.