In the ADR Agreement the tank group is dealt with under many headings, and the fact that companies first determine according to which ADR provisions their product will be designed and manufactured is important, as this is the starting point of the design approval process. When working on a tank design under ADR, the UN numbers of the dangerous goods to be carried must be determined (ADR Chapter 3.2.2, Table B: Alphabetical index of substances and articles of ADR). Using these numbers, the relevant design, construction and testing provisions (ADR Part 6), the packing provisions (ADR Chapters 4.2 and 4.3) and the special provisions for tanks (ADR Chapter 6.4) must be determined from ADR Table 3.2 A. ADR Part 6 contains 4 main headings on tanks.
For fixed metal tanks, which are widely produced in our country, the provisions on design, manufacture and testing are covered under ADR Chapter 6.8, while information such as the packing provisions, tank code, tank hierarchy, degree of filling and test pressures for Class 2 for these tanks is covered under ADR Chapter 4.3. The tank code given for a tank type provides information on the dangerous goods the tank may carry, as well as on its test or design pressures and its equipment. For example, according to ADR, a tank with the code LGBF may carry many flammable liquid dangerous goods such as UN 1203 (petrol) under ADR Chapter 3.2 Table A. Its design pressure is below 1.1 bar, and its bottom filling/discharge openings must be closed with triple protection. ADR Chapter 6.8 sets out the general provisions on tank design and manufacture, while detailed information for each tank type is given in the relevant standards.
For example;
- TS EN 13094 for tankers operating below 0.5 bar, such as fuel tankers,
- TS EN 12493 for LPG tankers,
- TS EN 13530-2 for vacuum-insulated cryogenic tanks
- TS EN 14398-2 for non-vacuum-insulated cryogenic tanks
- TS EN 14025 for other tanks. The validity periods of these standards are given in ADR 6.8.2.6.1, and companies need to follow the periods stated in this table.
Section 5 of Annex A of TS EN 13094, the standard for fuel tankers, explains in detail how the calculations are to be made. Companies should prepare their calculation notes according to this section. The strength of the tank against acceleration loads, which is not referred to in this section but must be checked for ADR, and the tank-to-chassis connections can be verified by Finite Element Analysis and/or strength calculations. TS EN 13094 and ADR 6.8 set out the cases and technical conditions in which a reduction of the tank's wall thickness is permitted, and companies need to state this in their applications with the relevant clause of the standard and the necessary calculations. The same applies to the protection of the equipment.
In short, the calculations and/or analyses required in an application for a fuel tanker are:
- Wall thickness calculations for the tank shell, ends and surge plates: TS EN 13094 Annex A
- Strength of the tank and the tank-to-chassis connections against accelerations: Finite Element Analysis and/or strength calculation
- Degree of filling and capacity calculation: ADR Chapter 4.3
- Calculations for the protection of the equipment: TS EN 13094 6.14. Technical drawings are needed to verify the calculations and analyses made for the tank.
These technical drawings are:
- General technical drawing (manufacturing drawing and sub-parts)
- Equipment
- Equipment protection
- Tank ends, compartments and surge plates
- Tank-to-chassis connections
- Piping
- Electrical circuit diagram
For other tank types, the calculations required for the design are specified in the relevant design and manufacturing standards. The other documents required in a design approval application, apart from those detailed here, are listed on the www.tmt.tse.org.tr (opens in a new tab) website. After the first stage of a design approval process, the file check and the verification of the calculations/analyses, the type approval tests of the tank produced to that design begin. All matters on this subject are set out in TS EN 12972. A design approval certificate is issued for a tank type that also passes the prototype tests. During the design approval procedure, TSE experts carry out audits at the company's premises on quality and on the manufacturability of the tank in question (examination of the machinery, equipment and staff infrastructure). If the company is found adequate, a certificate of conformity of production and production site is issued. The certificate of conformity of production and production site is valid for 3 years.
TS EN 12972 details the documents required and the tests to be carried out for the type approval inspection and for the initial, intermediate and periodic inspections. The file compiled during the initial inspection and prepared separately for each tank is called the Tank Record. The Tank Record should be prepared in 3 copies: one for the customer, one for TSE and one to remain with the company. The content of the tank record is detailed in the section of TS EN 12972 on the documents required for the initial inspection; in general, a tank record consists of the following documents:
- A copy of the Design Approval Certificate
- General technical drawing of the inspected tank
- Initial Inspection Certificate
- Copy of the tank plate (sealed)
- List of the equipment used on the inspected tank and of equivalent equipment that may be used in repairs
- List of materials used on the inspected tank and their certificates
- Reports of the inspections and tests carried out on the tank
- Record of repairs and maintenance carried out on the tank
- Heat treatment records
- WPS and PQR documents
- NDT personnel certificates
- Welder certificates
Under ADR, every tank to be produced must undergo an initial inspection. Tanks that have not undergone an initial inspection cannot obtain an ADR certificate of approval for the vehicle. For this reason, companies are expected to prepare their test procedures, to have the equipment needed for the tests and to calibrate it properly. Inspections are carried out under the supervision of the relevant TSE staff. Although it varies with the tank type, the initial inspection of a tank includes •Checking the design characteristics (measurement of the tank's dimensions and wall thickness) •Checking the inside and outside of the tank (the sheet and end materials used on the tank must be verifiable on the tank) •Hydrostatic pressure test (at the pressures verified in the design calculations) •Determination of the water capacity •Leakproofness test (at the pressures verified in the design calculations) and checking the equipment and its satisfactory operation. Tests and inspections other than these are specified in the design and manufacturing standards for the tanks. Although it varies with the type of ADR tank, intermediate inspections are required at 3-year intervals and periodic inspections once every 6 years. The hydrostatic pressure test is carried out in periodic inspections but not in intermediate inspections. Just as with the initial inspection, tanks that have not had their intermediate and periodic inspections are not issued an ADR certificate of approval for the vehicle. The inspection carried out after any repair to a tank is called an exceptional inspection. TSE must be informed before repairs are carried out on a tank; otherwise the repair may invalidate the tank's design type approval. Depending on the tests performed, an exceptional inspection replaces a periodic or intermediate inspection. You can find all information on the Tank Design Approval process (a knowledge base with detailed information on the processes, explanatory videos on the online application process, contact details of experts you can ask questions, etc.) at http://tmt.tse.org.tr/ (opens in a new tab).
