§ 179.101 Individual specification requirements applicable to pressure tank car tanks. § 179.101-1 Individual specification requirements. (a) In addition to § 179.100 the individual specification requirements are as follows: See footnotes at end of table. When steel of 65,000 to 81,000 p.s.i. minimum tensile strength is used, the thickness When steel of 65,000 p.s.i. minimum tensile strength is used, minimum thickness At least the upper two-thirds of the exterior of the tank, manway nozzle and all For inside diameter of 87 inches or less, the thickness of plates shall not be less See 179.102 for optional setting for certain commodities. See 179.103-1(c). See 179.103-3 for optional bottom loading and unloading. When the use of nickel is required by the lading, the thickness shall not be less than 2 inches. 10 Each tank head of class 112A tank car tanks may be equipped with not more [29 F.R. 18995, Dec. 29, 1964, as amended by Order 67, 30 F.R. 7425, June 5, 1965] § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to §§ 179.100 and 179. 101 the following requirements are applicable: § 179.102-1 Liquefied carbon dioxide. (a) Spec. 105A500-W or 105A600-W tank cars used to transport Liquefied carbon dioxide shall comply with the following special requirements: (1) All plates for tank, manway nozzle and anchorage, shall be made of steel complying with a specification approved for service at low temperatures. (2) Tank shall be insulated with an approved material of sufficient thickness so that the thermal conductance at 60 F is not more than 0.03 Btu per hour per square foot per degree F temperature differential; except that in order to permit an anchorage which shall not exceed seven inches from top of center sills to bottom of tank, the insulation thickness directly over the sills may be reduced to give thermal conductance not exceeding 0.04 Btu per hour per square foot per degree F temperature differential. (3) Tank shall be equipped with one safety relief valve set for the start-todischarge pressure listed in § 179.101, and one safety vent of approved design, set to function at a pressure less than the tank test pressure, and not less than 75 percent of tank test pressure. The discharge capacity of each of these safety relief devices shall be sufficient to prevent building up pressure in tank in excess of 822 percent of the tank test pressure. (4) Tank shall be equipped with two pressure-regulating valves of approved design, set to open at a pressure not exceeding 350 psi on spec. 105A500-W tanks or 400 psi on spec. 105A600-W tanks. (5) Each regulating valve and safety relief device shall have its final discharge piped to the outside of the protective housing. corkboard and constructed, maintained, and retested in compliance with spec. 105A500-W. Cars may be registered and jackets stenciled either 105A300-W or 105A500-W and equipped with the safety relief valve required by the specification to which registered. (2) The interior pipes of liquid discharge valves shall be equipped with excess flow valves of approved design. § 179.102-3 Liquefied flammable gases. (a) Spec. 105A100-W, 105A200-F, 105A200-W, 105A300-W, 105A400-W, 105A500-W, 105A600-W, 105A100-ALW, 105A200-ALW, 105A300-ALW, 112A200W, 112A340-W, 112A400-W or 112A500W tank cars used to transport liquefied flammable gases shall comply with the following special requirements: (1) The interior pipes of the loading and unloading valves, gaging device and sampling valve shall be equipped with excess flow valves of an approved design. (2) The protective housing cover shall be equipped with an approved weatherproof cover over an opening having an unrestricted area at least equal to the total safety relief valve discharge area. § 179.102-4 Vinyl fluoride, inhibited. (a) Spec. 105A600-W tank cars used to transport vinyl fluoride, inhibited, shall comply with the following special requirements: (1) Tank shall be insulated with an approved material of sufficient thickness so that the thermal conductance at 60 F is not more than 0.03 Btu per hour per square foot per degree F temperature differential; except that in order to permit an anchorage which shall not exceed seven inches from top of center sill to bottom of tank, the insulation thickness directly over the sills may be reduced to give thermal conductance not exceeding 0.04 Btu per hour per square foot per degree F temperature differential. (2) Tank shall be equipped with one safety relief valve, set for the start-todischarge pressure listed in § 179.101, and one safety vent of approved design, set to function at a pressure less than the tank test pressure, and not less than 75 percent of the tank test pressure. The discharge capacity of each of these safety relief devices shall be sufficient to prevent building up pressure in tank in excess of 822 percent of the tank test pressure. (3) Each regulating valve and safety relief device shall have its final discharge § 179.102-6 Vinyl chloride or Vinyl methyl ether, inhibited. (a) Spec. 105A200-W 112A400-W tank cars, used to transport Vinyl chloride, and spec. 105A100-W or 105A300-W tank cars used to transport Vinyl methyl ether, inhibited, shall comply with the following special requirements: (1) All parts of valves and safety relief devices in contact with the lading shall be of a metal or other material suitably treated, if necessary, which will not cause formation of any acetylides. (2. The interior pipes of the loading and unloading valves, gaging device and sampling valve shall be equipped with excess flow valves of an approved design. (3) For Vinyl chloride in spec. 105A200-W tank cars, openings in tank heads to facilitate nickel lining are authorized if closed in an approved manner. (a) Spec. 105A300-W tank cars used to transport Bromine shall comply with the following special requirements: (1) The tank shall be nickel clad at least 20 percent or shall be lined with lead at least 16 inch thick; openings in tank heads to facilitate application of lead lining are authorized if closed in an approved manner; all closures and appurtenances in contact with the lading shall be lead lined or shall be made of metal not subject to rapid deterioration by the lading; all interior welds in nickel clad tanks shall be protected by pure nickel butt straps to eliminate iron contamination. Except as otherwise provided herein, the water weight capacity of the tank shall not exceed 20,400 pounds. When tanks are equipped with manway cover plates, safety relief valves, (a) Spec. 105A300-W tank cars used to transport Motor fuel anti-knock compounds shall comply with the following special requirements: (1) Jacket shall be stenciled on both sides "MOTOR FUEL ANTI-KNOCK COMPOUND ONLY." Openings in tank heads to facilitate application of nickel lining are authorized if closed in an approved manner. § 179.102-9 Nitrogen tetroxide or Nitro gen tetroxide-nitric oxide mixtures. (a) Specs. 105A500-W and 105A600-W tank cars used to transport Nitrogen tetroxide or Nitrogen tetroxide-nitric oxide mixtures shall comply with the following special requirements: (1) Tanks shall be insulated with not less than four inches of corkboard. All valves and fittings shall be protected by the securely attached cover made of metal not subject to rapid deterioration by the lading, and all valve openings, except the safety relief valves, shall be fitted with screw plugs or caps to prevent leakage in the event of valve failure. Safety relief valve shall be equipped with an approved stainless steel or platinum frangible disc. Jacket shall be stenciled on both sides in letters not less than 2 inches high "NITROGEN TETROXIDE ONLY" or "NITROGEN TETROXIDENITRIC OXIDE MIXTURES ONLY," as applicable. Written procedure covering details of tank car appurtenances, manway fittings and safety relief devices, and marking, loading, handling, inspection and testing practices, shall be filed with and approved by the Bureau of Explosives before any tank car is offered for transportation of these commodities. § 179.102-10 Hydrocyanic acid. (a) Spec. 105A500-W or 105A600-W tank cars used to transport Hydrocyanic acid shall comply with the following special requirements: (1) Cars shall be registered and the jacket stenciled spec. 105A300-W and be equipped with the safety relief valves required by that specification. Tanks § 179.102 Special commodity requirements for pressure tank car tanks. (a) In addition to §§ 179.100 and 179. 101 the following requirements are applicable: § 179.102-1 Liquefied carbon dioxide. (a) Spec. 105A500-W or 105A600-W tank cars used to transport Liquefied carbon dioxide shall comply with the following special requirements: (1) All plates for tank, manway nozzle and anchorage, shall be made of steel complying with a specification approved for service at low temperatures. (2) Tank shall be insulated with an approved material of sufficient thickness so that the thermal conductance at 60 F is not more than 0.03 Btu per hour per square foot per degree F temperature differential; except that in order to permit an anchorage which shall not exceed seven inches from top of center sills to bottom of tank, the insulation thickness directly over the sills may be reduced to give thermal conductance not exceeding 0.04 Btu per hour per square foot per degree F temperature differential. (3) Tank shall be equipped with one safety relief valve set for the start-todischarge pressure listed in § 179.101, and one safety vent of approved design, set to function at a pressure less than the tank test pressure, and not less than 75 percent of tank test pressure. The discharge capacity of each of these safety relief devices shall be sufficient to prevent building up pressure in tank in excess of 822 percent of the tank test pressure. (4) Tank shall be equipped with two pressure-regulating valves of approved design, set to open at a pressure not exceeding 350 psi on spec. 105A500-W tanks or 400 psi on spec. 105A600-W tanks. (5) Each regulating valve and safety relief device shall have its final discharge piped to the outside of the protective housing. corkboard and constructed, maintained, and retested in compliance with spec. 105A500-W. Cars may be registered and jackets stenciled either 105A300-W or 105A500-W and equipped with the safety relief valve required by the specification to which registered. (2) The interior pipes of liquid discharge valves shall be equipped with excess flow valves of approved design. § 179.102-3 Liquefied flammable gases. (a) Spec. 105A100-W, 105A200-W, 105A300-W, 105A200-F, 105A400-W, 105A500-W, 105A600-W, 105A100-ALW, 105A200-ALW, 105A300-ALW, 112A200W, 112A340-W, 112A400-W or 112A500W tank cars used to transport liquefied flammable gases shall comply with the following special requirements: (1) The interior pipes of the loading and unloading valves, gaging device and sampling valve shall be equipped with excess flow valves of an approved design. (2) The protective housing cover shall be equipped with an approved weatherproof cover over an opening having an unrestricted area at least equal to the total safety relief valve discharge area. § 179.102-4 Vinyl fluoride, inhibited. (a) Spec. 105A600-W tank cars used to transport vinyl fluoride, inhibited, shall comply with the following special requirements: (1) Tank shall be insulated with an approved material of sufficient thickness so that the thermal conductance at 60 F is not more than 0.03 Btu per hour per square foot per degree F temperature differential; except that in order to permit an anchorage which shall not exceed seven inches from top of center sill to bottom of tank, the insulation thickness directly over the sills may be reduced to give thermal conductance not exceeding 0.04 Btu per hour per square foot per degree F temperature differential. (2) Tank shall be equipped with one safety relief valve, set for the start-todischarge pressure listed in § 179.101, and one safety vent of approved design, set to function at a pressure less than the tank test pressure, and not less than 75 percent of the tank test pressure. The discharge capacity of each of these safety relief devices shall be sufficient to prevent building up pressure in tank in excess of 822 percent of the tank test pressure. (3) Each regulating valve and safety relief device shall have its final discharge |