Protective Direction No. 37

I , Marc Garneau, Minister of Transport, am issuing this Protective Direction under section 32 of the Transportation of Dangerous Goods Act, 1992 (Act) and considering it necessary to deal with an emergency that involves a danger to public safety, do hereby direct that

  1. Subject to the specifications for the pressure relief device set out in (2), top fittings of a tank car referred to in section 5.15.8 of the Transportation of Dangerous Goods Regulations shall, in addition to the conditions set out in section 5.15.8, be located inside a protective housing not less than 12.5 mm (1/2 in.) in thickness and constructed of a material having a tensile strength not less than 450 MPa (65 000 psi) and conform to the following specifications:
    1. the protective housing shall be as tall as the tallest valve or fitting involved and the height of a valve or fitting within the protective housing must be kept to the minimum compatible with their proper operation;
    2. the protective housing or cover may not reduce the flow capacity of the pressure relief device below the minimum required;
    3. the protective housing shall provide a means of drainage with a minimum flow area equivalent to six holes, each having a diameter of 25.4 mm (1 in.); and
    4. when connected to the nozzle or fitting cover plate and subject to a horizontal force applied perpendicular to and uniformly over the projected plane of the protective housing, the tensile connection strength of any protective housing shall be designed to be:
      1. no greater than 70 percent of the nozzle to tank tensile connection strength;
      2. no greater than 70 percent of the cover plate to nozzle connection strength; and,
      3. no less than either 40 percent of the nozzle to tank tensile connection strength or the shear strength of twenty 12.5 mm (1/2 in.) nominal diameter bolts.
  2. The pressure relief device is located as follows:
    1. It is located inside the protective housing, unless space does not permit and in that case, only one pressure relief device can be located outside of a protective housing;
    2. the highest point of any pressure relief device that is located outside of a protective housing must not be more than 305 mm (12 in.) above the tank jacket; and,
    3. the highest point on the closure of any unused pressure relief device nozzle must not be more than 152 mm (6 in.) above the tank jacket.

This Protective Direction takes effect on June 6, 2016.  It remains in effect until the earliest of

  • the day it is cancelled in writing by the Minister of Transport, or
  • the day on which a regulation respecting the above mentioned subject matter is made under section 27 of the Act.

SIGNED AT OTTAWA, ONTARIO, this 31 day of May 2016.

The Honourable Marc Garneau

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