2 The principal properties and hazards of chlorine are as follows:
(a) chlorine is normally transported under pressure in liquid form in tank cars and cylinders. Under atmospheric conditions, such as would be obtained in the event of a leak, liquid chlorine is rapidly converted to a gas in the ratio of approximately one volume of liquid to 460 volumes of gas. For this reason a relatively small leak of liquid chlorine is capable of polluting a large volume of air;
(b) chlorine gas is about 2 1/2 times as heavy as air. It therefore tends to accumulate in low places and is not readily diluted or dispersed unless it is subjected to strong air currents;
(c) chlorine is not flammable, but at ordinary temperatures it will support the combustion of some combustible, organic substances such as finely divided cork. At elevated temperatures it will support the combustion of steel and for this reason may cause the rapid deterioration of steel piping or other steel equipment that is exposed to a fire;
(d) although insulated chlorine tank cars of the ICC 105A type provide good thermal protection for the lading, they should be removed from the scene of a fire as soon as possible;
2 In these Regulations,
railway station-dwelling means a railway station building, part of which is used as a dwelling; (gare-habitation)
tank car means any vessel described as a tank car in the Regulations for the Transportation of Dangerous Commodities by Rail and is approved by the Commission for chlorine service, but does not include multi-unit tank cars such as the ICC 106A500-X tank car. (wagon-citerne)
37 (1) Except as provided in subsection (2), the shut-off valves shall be closed and the unloading pipelines disconnected from the tank car immediately after the completion of unloading operations.
(2) Pipelines need not be disconnected from the tank car if all shut-off valves on the tank car and in the discharge lines are closed, the tank car is protected as provided in sections 34 to 36 and the period during which operations are suspended does not exceed 72 hours.
24 (1) Prior to being placed in service for the first time and prior to being returned to service after a repair, the piping system shall receive a hydrostatic and a pneumatic test as prescribed in subsections (2) and (3).
(3) After the hydrostatic test, the piping system shall be thoroughly dried and cleaned, then tested for leaks with dry air at 150 psig, as recommended by The Chlorine Institute in its Pamphlet No. 6, dated January 18, 1962, and amendments thereto.
21 (1) Except as provided in section 22, only steel pipe, fittings and valves shall be used. They shall not be less than 3/4 inch nominal diameter and shall comply with the standards prescribed in Tables I and II of Schedule II, or other standards recommended by The Chlorine Institute and approved by the Commission.
(3) Gaskets, joint compound and valve packing shall comply with the recommendations of The Chlorine Institute as contained in its Pamphlet No. 6, dated January 18, 1962, and amendments thereto.