EN 12285-1 pdf free download

EN 12285-1 pdf free download. Workshop fabricated steel tanks – Part 1: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and non-flammable water polluting liquids.
6.2 Materials for shell, dished ends and manholes Carbon steel according to EN 10025 or austenitic stainless steel according to EN 10088-1 may be used if the mechanical properties are at least equal to those of S 235 JR (EN 10025). In areas where low temperatures have to be considered (below -20°C) and in this case wall-thicknesses are 6 mm, at least carbon steel of grade S 235 J2G3 or equal shall be used. 6.3 Materials for tank accessories Materials used for the fabrication of tank accessories if welded to the tank shall be compatible with the tank material. 6.4 Consumable All welding rods/wires and other consumables shall be compatible with the basic material. 6.5 Material inspection documentation Material inspection documentation of shell plates and dished ends shall for carbon steel according to EN 10025 be in accordance with the requirements of 2.2 of EN 10204: 1991 and for all other steel qualities shall be in accordance with 3.1 B of EN 10204: 1991. 7 Design 7.1 Forms of construction Single skin tanks shall form an impermeable containment; they constitute the inner tank of a double skin tank. 7.2 Single skin tanks Single skin tanks shall form an impermeable containment; they constitute the inner tank of a double skin tank. 7.3 Double skin tanks For double skin tanks, a secondary skin is welded around the inner tank, which forms an impermeable self contained tank. The secondary skin shall cover at least 97 % of the nominal volume of the inner tank. 7.5 Compartments The nominal wall thicknesses of dished ends separating the compartments (compartment dished ends) are given in Table 3. For classes A and B a different form of dished ends separating the compartments is possible, where r 1 = d 1 , but without knuckle radius r 2 and without straight flange. A compartment dished end with a knuckle radius and a straight flange is equivalent to a reinforcement ring at the same position. 7.6.2 Secondary skin – Circumferential angle The secondary skin shall enclose at least 300 degrees of the circumference of the tank, leaving not more than 60 degrees on the top uncovered. In cases where the manhole diameter exceeds d 1 /2, the manhole shall be provided with a secondary skin. 7.6.3 Interstitial space The interstitial space gap should be as small as practically possible but suitable for the leak detection system to function. 7.7 Tolerances 7.7.1 The overall length of the inner tank The tolerance on the overall length of the tank shall be ± 1% of the real length stated by the manufacturer. 7.7.2 Wall thickness The minimum thicknesses of dished ends after forming and for shell plates shall be at least 92 % of the nominal wall thickness according to Table 3. The thickness of shell plates shall be in accordance with EN 10051:1991, Table 2. 7.7.3 Circumference of dished ends For the dished ends, the tolerances shall be -0/+6 mm for d 1 ≤ 2000 mm, and -0/+10 mm for d 1 > 2000 mm based on the calculated circumference of d 1 . 7.8 Shell plate arrangement Cross seams are not allowed. Longitudinal welds are not allowed in the bottom half of the tank.EN 12285-1  pdf download.