UN 3257 Aluminium, molten RID 2025 (Shortinfo)

Carriage in bulk is permitted in specially equipped wagons or large containers in accordance with standards specified by the competent authority of the country of origin. If the country of origin is not a Contracting State to RID, the conditions laid down shall be recognized by the competent authority of the first country Contracting State to RID reached by the consignment.

In accordance with VC 3 in 7.3.3.1, for the purpose of carriage in bulk of molten aluminium, "standards specified by the competent authority of the country of origin" means that the following requirements shall be met. 1. General requirements 1.1 Vat means a containment intended for the carriage of molten aluminium of UN No. 3257, including its shell, refractory lining and service and structural equipment. 1.2 Vats shall be insulated so as not to exceed a surface temperature of 130 °C during carriage and shall be so positioned that the means of containment cannot be touched by other persons under normal conditions of carriage. The surface temperature shall in no case have a detrimental effect on the functioning of the wagon. 1.3 The vats shall be secured on the wagon in accordance with the load securing principles of 7.5.7.1. 1.4 Vats need not be affixed with placards and markings in accordance with Chapter 5.3 if these placards and markings have been affixed to the wagon. 2. Fire and explosion protection The risk of fire by the thermal influence of the molten aluminium on the vat, the wagon or load securing aids, and the risk of explosion resulting from escaping vapours or chemical reaction of gases that have evolved, shall be prevented (e.g. by using inert gases). 3. Construction of vats Vats shall be made of steel. Vats shall be designed and manufactured for a test pressure of 4 bar in accordance with EN 13445-3:2014. In the course of construction, the manufacturer shall specify the weld seams that are subject to the highest stresses. The hydrostatic pressure and surge effect of the molten aluminium shall be taken into account when deciding the dimensions of the vats and their attachment to the wagon. The forces in 6.8.2.1.2 shall be taken into account. The vat closures shall be designed in accordance with EN 13445-3:2014 and shall remain leakproof if a vat with contents (lateral position and top of the vat) overturns. The filling and discharge openings shall be protected by the construction of the vat, e.g. by collars, deflectors, cages or equivalent constructions. The protective device on the top of the vat shall be designed so as to withstand, without permanent deformation, a static load, applied vertically on the filling cover, equal to twice the maximum permissible mass of the vat (2g). The refractory lining shall be suitable to withstand the contents and it shall be suitable as insulation material. The refractory lining shall be so designed that its leakproofness remains intact, whatever the deformation liable to occur in normal conditions of carriage (see 6.8.2.1.2). The inspection body performing inspections in accordance with 6.8.2.4.1 or 6.8.2.4.4, shall verify and confirm the ability of the manufacturer or the maintenance or repair shop to perform welding operations and the operation of a weld quality assurance system. Welding work on the sheet metal jacket, in particular on load-bearing parts, may only be carried out by approved welding companies. Seals on vat covers and closures shall be selected and applied so that they prevent molten aluminium from flowing out if a full vat overturns. 4. Inspection and tests of vats The inspections and tests described in 4.1 to 4.5 shall be carried out by an inspection body approved by the competent authority. The inspections and tests shall be carried out in accordance with the applicable requirements of EN 12972:2018 + A1:[2024]. Test reports on the results of the tests performed shall be issued. 4.1 Type examination of vats The construction design and workmanship shall be tested as part of a type examination procedure to ensure that the vats comply with the construction requirements of EN 13445-3:2014. The weld seams subject to the highest stresses shall be identified in the type examination report. 4.2 Initial inspection Vats shall be tested and inspected before they are placed in service. The test shall at least include: (a) A check to ensure that the vat is in line with the type examination documents; (b) A check of conformity to the type; (c) An examination of the external condition; (d) A hydraulic pressure test at a test pressure of 4 bar; at this stage, the vats shall not have a refractory lining; (e) An examination of the internal condition (visual inspection of the internal metal surface of the vat before the refractory lining is fitted and visual inspection of the refractory lining); (f) A check of satisfactory operation of the equipment. The hydraulic pressure test can also be carried out with an alternative seal. 4.3 Intermediate inspection Vats shall undergo an intermediate inspection no later than six years after the initial inspection and each periodic inspection. The intermediate inspection shall at least include: (a) An examination of the documents; (b) An examination of the external condition, including the integrity of the flange and cover connections; (c) Measurement of the wall thickness to check the required minimum wall thickness; (d) Non-destructive testing of weld seams that are subject to the highest stresses by magnetic particle testing, penetration testing, ultrasonic testing or radiographic testing; (e) An examination of the internal condition (visual inspection of the refractory lining) by an expert under the responsibility of the operator; (f) A check of satisfactory operation of the equipment. These intermediate inspections may be performed within three months before the specified date, without any influence on the time frame of other inspections according to 4.3 and 4.4. 4.4 Periodic inspection Each time the refractory lining is renewed, or no later than twelve years after the initial or most recent periodic inspection, a periodic inspection shall be carried out. The periodic inspection shall at least include: (a) An examination of the documents; (b) An examination of the external condition, including the integrity of the flange and cover connections; (c) An examination of the internal condition (visual inspection of the internal metal surface of the vat before the refractory lining is fitted and visual inspection of the refractory lining); (d) Non-destructive testing of all weld seams that are subject to the highest stresses shall be carried out by magnetic particle testing, penetration testing, ultrasonic testing or radiographic testing; (e) Measurement of the wall thickness to check the required minimum wall thickness: (f) Hydraulic pressure test at a test pressure of 4 bar, at this stage, the vats shall not have a refractory lining; (g) A check of satisfactory operation of the equipment. The hydraulic pressure test can also be carried out with an alternative seal. 4.5 Exceptional inspection of vats When the safety of the vat or of its equipment may have been impaired as a result of repairs, alterations or accident, an exceptional inspection shall be carried out on the parts affected by the repairs or alterations. If the exceptional inspection fulfilling the requirements of 4.4 has been performed, then the exceptional inspection may be considered to be a periodic inspection. If an exceptional inspection fulfilling the requirements of 4.3 has been performed, then the exceptional inspection may be considered to be an intermediate inspection. The inspection body shall decide the detailed scope of the exceptional inspection, taking into account EN 12972:2018 + A1:[2024], Table A1. 5. Marking of vats Vats shall be marked with a plate by analogy with 6.8.2.5.1, except the approval number and external design pressure. For the tests and inspections in accordance with 4.2 and 4.4, the marking shall be followed by "P". For the tests and inspections in accordance with 4.3, the marking shall be followed by "L". 6. Requirements for operation The owner or the operator shall keep a copy of the type examination report, the results of the initial tests and inspections and all subsequent tests and inspections in the vat file. Every renewal and repair of the refractory lining shall be recorded by the operator or manufacturer. Seals shall be checked with each filling and renewed if necessary. Vats shall be positioned on the wagons in such a way that the discharge openings face or are opposite to the direction of travel.