oSIST prEN 12285-1:2014

Workshop fabricated steel tanks - Part 1: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids

This standard specifies the product characteristics and test/assessment methods for workshop fabricated cylindrical, horizontal steel tanks, single (type S) and double skin (type D) intended to be used for the underground storage of water polluting liquids (both flammable and non-flammable) at normal ambient temperature conditions (-20 °C to +50 °C) within the following limits:
   from 800 mm up to 3000 mm nominal diameter and,
   up to a maximum overall length of 6 times the nominal diameter
   for liquids with a maximum density of up to 1,9 kg/l and,
   with an operating pressure (Po) of maximum 1,5 bar (abs.) and,
   for double skin tanks with a vacuum leak detection system where the kinematic viscosity does not exceed 5  10-3 m2/s.
Tanks designed to this standard allow for an earth cover of 1.5m and for the tank to withstand traffic loads from a properly constructed roadway
This standard is not applicable for the storage of liquids having dangerous good classes listed in Table 1 because of the special dangers involved.

Werksgefertigte Tanks aus Stahl - Teil 1:Liegende zylindrische ein- und doppelwandige Tanks zur unterirdischen Lagerung von brennbaren und nicht brennbaren wassergefährdenden Flüssigkeiten, Deutsche Fassung prEN 12285-1:2012

Diese Norm legt die Produkteigenschaften sowie Prüf /Bewertungsverfahren für werksgefertigte zylindrische, liegende, einwandige (Typ S) und doppelwandige (Typ D) Stahltanks zur unterirdischen Lagerung von (brennbaren und nichtbrennbaren) wassergefährdenden Flüssigkeiten bei normalen Umgebungstemperatur-bedingungen (20 °C bis 50 °C) mit folgenden Anwendungsgrenzen fest:
-   Nenndurchmesser von 800 mm bis 3 000 mm; und
-   maximale Gesamtlänge bis zum 6fachen des Nenndurchmessers; und
-   für Flüssigkeiten mit einer maximalen Dichte von 1,9 kg/l; und
-   mit einem Betriebsdruck (po) von höchstens 1,5 bar (abs.); und
-   für doppelwandige Tanks mit einem Vakuum-Leckanzeigesystem, wenn die kinematische Viskosität des Lagermediums den Wert 5  103 m2/s nicht übersteigt.
Für nach dieser Norm ausgelegte Tanks ist eine Erdüberdeckung bis 1,5 m zulässig, und sie widerstehen Verkehrslasten einer ordnungsgemäß ausgebildeten Fahrbahn.
Diese Norm ist nicht für die Lagerung von Flüssigkeiten anwendbar, welche unter die in Tabelle 1 aufgeführten Gefahrgutklassen fallen, da von ihnen besondere Gefahren ausgehen.

Réservoirs en acier fabriqués en atelier - Partie 1: Réservoirs horizontaux cylindriques à simple ou double paroi pour le stockage enterré de liquides inflammables et non inflammables polluant l'eau

La présente norme définit les caractéristiques de produit et les méthodes d'essai/d'évaluation pour les réservoirs en aciers cylindriques, horizontaux, fabriqués en atelier, à simple (type S) et double paroi (type D), destinés à être utilisés pour le stockage enterré de liquides polluant l'eau (inflammables et non inflammables) dans des conditions normales de températures ambiantes (-20 °C à +50 °C), et compris dans les limites suivantes :
-   diamètre nominal compris entre 800 mm et 3 000 mm ;
-   longueur maximale d'encombrement égale à 6 fois le diamètre nominal ;
-   pour les liquides présentant une masse volumique maximale égale à 1,9 kg/l ;
-   avec une pression de service (Po) maximale de 1,5 bar (absolue) ;
-   lorsque des réservoirs à double paroi, munis d'un système de détection de fuites du vide, la viscosité ne doit pas être supérieure à 5 10-3 m2/s.
Les réservoirs doivent être conçus pour supporter une hauteur de remblai de 1,5 m et pour le réservoir de résister aux charges induites par la circulation sur une route correctement construite
La présente norme ne s'applique pas au stockage de liquides aux classes de matières dangereuses énumérées au Tableau 1, en raison des dangers spécifiques pouvant être engendrés.

V delavnici izdelani jekleni rezervoarji - 1. del: Enoplaščni in dvoplaščni ležeči valjasti rezervoarji za podzemno skladiščenje gorljivih in negorljivih tekočin, ki onesnažujejo vodo

General Information

• Status: Not Published
• Public Enquiry End Date: 10-Aug-2014
• ICS: 13.300 - Protection against dangerous goods
• ICS: 23.020.10 - Stationary containers and tanks
• Technical Committee: TLP - Pressure vessels
• Current Stage: 98 - Abandoned project (Adopted Project)
• Start Date: 07-Mar-2016
• Due Date: 12-Mar-2016
• Completion Date: 07-Mar-2016
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Directive: 89/106/EEC - Construction products
• Mandate: M/131 - Mandate to CEN/CENELEC concerning the execution of standardization work for harmonized standards on pipes, tanks and ancillaries, not in contact with water intended for human consumption
• Ref Project: prEN 12285-1 rev - Workshop fabricated steel tanks - Part 1: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids

Relations

• Child: SIST EN 12285-1:2018 - Workshop fabricated steel tanks - Part 1: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids other than for heating and cooling of buildings
• Effective Date: 27-Jul-2022
• Child: SIST EN 12285-3:2019 - Workshop fabricated steel tanks - Part 3: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids for heating and cooling of buildings
• Effective Date: 08-Jun-2022
• Child: SIST EN 12285-3:2019 - Workshop fabricated steel tanks - Part 3: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids for heating and cooling of buildings
• Effective Date: 25-Mar-2020
• Child: SIST EN 12285-1:2018 - Workshop fabricated steel tanks - Part 1: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids other than for heating and cooling of buildings
• Effective Date: 25-Mar-2020
• Revised: SIST EN 12285-1:2018 - Workshop fabricated steel tanks - Part 1: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids other than for heating and cooling of buildings
• Effective Date: 15-Jun-2022
• Revised: SIST EN 12285-1:2003 - 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
• Effective Date: 08-Jun-2022
• Revised: SIST EN 12285-3:2019 - Workshop fabricated steel tanks - Part 3: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids for heating and cooling of buildings
• Effective Date: 01-Sep-2016
• Revised: SIST EN 12285-1:2003 - 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
• Effective Date: 12-Dec-2009
• Child: SIST EN 12285-1:2018 - Workshop fabricated steel tanks - Part 1: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids other than for heating and cooling of buildings
• Effective Date: 16-Dec-2020
• Child: SIST EN 12285-3:2019 - Workshop fabricated steel tanks - Part 3: Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and nonflammable water polluting liquids for heating and cooling of buildings
• Effective Date: 15-Jul-2020

Overview

prEN 12285-1 rev - Workshop fabricated steel tanks covers requirements for horizontal cylindrical single skin (type S) and double skin (type D) steel tanks intended for the underground storage of flammable and non‑flammable water‑polluting liquids. The draft CEN standard applies to workshop‑fabricated tanks for normal ambient temperatures (‑20 °C to +50 °C) and defines product characteristics, testing and assessment methods, marking and conformity procedures.

Key built‑in limits:

• Nominal diameters from 800 mm to 3000 mm
• Maximum overall length up to 6 × nominal diameter
• Liquids with density ≤ 1.9 kg/l
• Operating pressure Po ≤ 1.5 bar (abs.)
• Double skin tanks with vacuum leak detection: kinematic viscosity ≤ 5 × 10^-3 m²/s
• Design allows 1.5 m earth cover and to withstand traffic loads from a roadway
• Excludes storage of certain UN dangerous goods (e.g., explosives, organic peroxides, infectious or radioactive substances)

Key topics

• Product characteristics: materials, welding, additional fabrication requirements and mechanical stability for single and double skin designs.
• Testing and assessment: mechanical strength, load‑bearing, tightness (gas/liquid), crushing resistance, electrostatic behaviour (for fuel networks) and interstitial testing for double skins.
• Welding and materials: conformity to steel and welding reference standards (examples in normative references include EN 10025, EN ISO 15614‑1).
• Durability and leakage control: vacuum leak detection for double skin tanks and provisions for long‑term containment of water‑polluting liquids.
• Conformity & AVCP: clauses on Assessment and Verification of Constancy of Performance (AVCP), factory production control (FPC), type testing and CE marking (see Annex ZA for CPR alignment).
• Documentation and marking: tank certificates, labelling and purchaser specification/designation.

Applications

Who uses prEN 12285-1 rev:

• Tank manufacturers and fabricators designing workshop‑built underground tanks
• Project engineers and specifiers for commercial forecourts, fuel storage, chemical handling and environmental protection projects
• Installation contractors and site planners (ensuring earth cover and roadway load requirements)
• Testing laboratories conducting tightness, pressure and crushing tests
• Regulatory bodies assessing compliance and CE marking for tanks within the EU construction products framework

Practical benefits include standardized safety, predictable performance under specified loads and temperatures, and harmonized testing and documentation for underground storage of water‑polluting liquids.

Related standards

This draft references complementary standards for steel materials, welding procedures and fasteners (examples: EN 10025, EN ISO 15614‑1, EN 287‑1) and is part of the CEN family addressing storage tanks (EN 12285 series).

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2014
9GHODYQLFLL]GHODQLMHNOHQLUH]HUYRDUMLGHO(QRSODãþQLLQGYRSODãþQLOHåHþL
YDOMDVWLUH]HUYRDUML]DSRG]HPQRVNODGLãþHQMHJRUOMLYLKLQQHJRUOMLYLKWHNRþLQNL
RQHVQDåXMHMRYRGR
Workshop fabricated steel tanks - Part 1: Horizontal cylindrical single skin and double
skin tanks for the underground storage of flammable and nonflammable water polluting
liquids
Werksgefertigte Tanks aus Stahl - Teil 1:Liegende zylindrische ein- und doppelwandige
Tanks zur unterirdischen Lagerung von brennbaren und nicht brennbaren
wassergefährdenden Flüssigkeiten, Deutsche Fassung prEN 12285-1:2012
Ta slovenski standard je istoveten z: prEN 12285-1 rev
ICS:
13.300 Varstvo pred nevarnimi Protection against dangerous
izdelki goods
23.020.10 1HSUHPLþQHSRVRGHLQ Stationary containers and
UH]HUYRDUML tanks
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
DRAFT
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2014
ICS 13.300; 23.020.10 Will supersede EN 12285-1:2003
English Version
Workshop fabricated steel tanks - Part 1: Horizontal cylindrical
single skin and double skin tanks for the underground storage of
flammable and nonflammable water polluting liquids
Réservoirs en acier fabriqués en atelier - Partie 1: Werksgefertigte Tanks aus Stahl - Teil 1: Liegende
Réservoirs horizontaux cylindriques à simple ou double zylindrische ein- und doppelwandige Tanks zur
paroi pour le stockage enterré de liquides inflammables et unterirdischen Lagerung von brennbaren und
non inflammables polluant l'eau nichtbrennbaren wassergefährdenden Flüssigkeiten
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 265.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12285-1 rev:2014 E
worldwide for CEN national Members.

prEN 12285-1:2014 (E)
Contents Page
Foreword .4
Introduction .5
1 Scope .6
2 Normative references .6
3 Terms, definitions, symbols and abbreviations .7
3.1 Terms and definitions .7
3.2 Symbols and abbreviations .8
4 Product characteristics .9
4.1 General .9
4.2 Welding .9
4.3 Additional requirements . 12
4.4 Mechanical resistance and stability. 15
4.5 Internal pressure . 17
4.6 Electrostatic behaviour (for fuel networks) . 18
4.7 Tightness (gas and liquid) . 18
4.8 Release of dangerous substances . 18
4.9 Durability . 18
4.10 Crushing resistance . 18
5 Testing, assessment and sampling methods . 19
5.1 Mechanical resistance and stability. 19
5.2 Load-bearing capacity . 19
5.3 Electrostatic behaviour (for fuel networks) . 19
5.4 Tightness (gas and liquid) . 19
5.5 Crushing resistance . 20
6 Assessment and verification of constancy of performance (AVCP) . 21
6.1 General . 21
6.2 Type testing . 21
6.3 Factory production control (FPC) . 24
7 Classification . 28
7.1 Tank type . 28
7.2 Tank classes . 28
7.3 Designation and purchaser's specification . 28
8 Marking and labelling . 29
8.1 Marking of the tank . 29
8.2 Tank certificate . 29
8.3 Documentation . 29
Annex A (informative) Transport, storage and installation procedure . 30
A.1 Transport . 30
A.2 Storage . 30
A.3 Installation procedure . 30
Annex B (informative) Evaluation of liquid-material-combinations for storage tanks according to this
standard . 33
B.1 General . 33
B.2 Criteria for evaluation . 33
B.3 Evaluation of liquids not mentioned in the positive-liquid-list . 34
B.4 Use of the positive-liquid-list . 34
Annex ZA (informative) Clauses of this European Standard addressing the provisions of the EU
Construction Products Regulation . 157
prEN 12285-1:2014 (E)
ZA.1 Scope and relevant characteristics . 157
ZA.2 Procedure for AVCP of workshop fabricated cylindrical, horizontal steel tanks, single and
double skin . 158
ZA.2.2.3 Example of DoP . 161
ZA.3 CE marking and labelling . 163

prEN 12285-1:2014 (E)
Foreword
This document (prEN 12285-1:2014) has been prepared by Technical Committee CEN/TC 265 “Metallic tanks for
the storage of liquids”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 12285-1:2003.
This document has been prepared under a mandate given to CEN by the European Commission and the European
Free Trade Association, and supports essential requirements of EU Directive.
For relationship with EU Directive, see informative Annex ZA, which is an integral part of this document.
This document will supersede EN 12285-1:2003.
Compared to EN 12285-1:2003, this draft has been restructured as follows:
 Old Clause 3 Terms and definitions has been combined with old Clause 4 Symbols and abbreviations
 Old Clause 5 Designation and purchaser's specification has been combined with new Clause 7 Classification
and designation
 Old Clause 6 Materials, Clause 7 Design, Clause 8 Fabrication and Clause 10 Handling and installation have
been replaced by new Clause 4 Product characteristics
 Old Clause 9 Testing has now become Clause 5 Testing, assessment and sampling methods
 Old Clause 11 Marking of the tank and manufacturer's statement has now been combined with new Clause 8
Marking, labelling and packaging
In addition, prEN 12285-1 includes a new clause as follows:

 Clause 6 Assessment and verification of constancy of performance (AVCP)
Furthermore, Annex ZA has been revised to align with the Construction Products Regulation (CPR) (305/2011).
Annex ZA does not apply to the tanks installed in industrial processes, nor in petrol stations as these products are
excluded from the mandate M/131 "Pipes, tanks and ancillaries not in contact with water intended for human
consumption" (see Annex I of the mandate M/131).
The informative annexes A and B give further guidance; A on transport, storage and installation procedures and B
on the liquid-material combinations to be chosen.
prEN 12285-1:2014 (E)
Introduction
This European Standard is part of a family of standards involving storage tanks . Normal ambient temperatures
considered in this standard are -20 °C to +50 °C. Where temperatures are outside this range it could become
necessary to consider further requirements. These could include temperature control measures or material control
(see 4.2.2).
CEN/TC 265 WG8
Shop fabricated metallic tanks

Underground tanks Aboveground tanks
(EN 12285-1) (EN 12285-2)
prEN 12285-1:2014 (E)
1 Scope
This standard specifies the product characteristics and test/assessment methods for workshop fabricated
cylindrical, horizontal steel tanks, single (type S) and double skin (type D) intended to be used for the underground
storage of water polluting liquids (both flammable and non-flammable) at normal ambient temperature conditions (-
20 °C to +50 °C) within the following limits:
 from 800 mm up to 3000 mm nominal diameter and,
 up to a maximum overall length of 6 times the nominal diameter
 for liquids with a maximum density of up to 1,9 kg/l and,
 with an operating pressure (P ) of maximum 1,5 bar (abs.) and,
o
 for double skin tanks with a vacuum leak detection system where the kinematic viscosity does not exceed
-3 2
5 × 10 m /s.
Tanks designed to this standard allow for an earth cover of 1.5m and for the tank to withstand traffic loads from a
properly constructed roadway
This standard is not applicable for the storage of liquids having dangerous good classes listed in Table 1 because of
the special dangers involved.
Table 1 — List of dangerous goods the storage of which are not covered by this standard
UN- Dangerous Good
classification
Class 1 Explosives
Class 4.2 Substances liable to spontaneous combustion
Class 4.3 Substances which in contact with water emit flammable gases
Class 5.2 Organic peroxides
Class 6.2 Infectious substances
Class 7 Radioactive substances, hydrocyanic or hydrocyanic solvent liquids, metal carbons, hydrofluoric acid,
bromide liquids
NOTE The classifications referred to are those adopted by the United Nations Committee of Experts on the Transport of
Dangerous Goods (not to be interpreted as tank classes described in 7.2.)
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for
its application. For dated references, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
EN 287–1, Qualification test of welders — Fusion welding — Part 1: Steels.
EN 10025, Hot rolled products of non-alloy structural steels — Technical delivery conditions.
EN 10028–2, Flat products made of steels for pressure purposes — Part 2: Non-alloy and alloy steels with
specified elevated temperature properties.
EN 10028-7, Flat products made of steels for pressure purposes — Part 7: Stainless steels.
prEN 12285-1:2014 (E)
EN 10051:1997, Continuously hot-rolled uncoated plate, sheet and strip of non-alloy and alloy steels — Tolerances
on dimensions and shape.
EN 10088–1, Stainless steels — Part 1: List of stainless steels.
EN 10204:1995, Metallic products — Types of inspection documents.
EN ISO 898–1, Mechanical properties of fasteners made of carbon steel and alloy steel - Part 1: Bolts, screws and
studs (ISO 898-1).
EN ISO 8501–1, Preparation of steel substrates before application of paints and related products - Visual
assessment of surface cleanliness — Part 1: Rust grades and preparation grades of uncoated steel substrates and
of steel substrates after overall removal of previous coatings (ISO 8501-1).
EN ISO 15607, Specification and qualification of welding procedures for metallic materials — General rules (ISO
15607)
EN ISO 15609-1, Specification and qualification of welding procedures for metallic materials — Welding procedure
specification — Part 1: Arc welding (ISO 15609-1)
EN ISO15614-1, Specification and qualification of welding procedures for metallic materials — Welding procedure
test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys (ISO 15614-1)
3 Terms, definitions, symbols and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
tank
workshop fabricated cylindrical containments for the storage of liquids
Note 1 to entry: They are made of steel plates, equipped with dished ends and consist of one or more compartments
3.1.2
underground tank
tank which is totally or partially imbedded in the ground
3.1.3
compartment
single storage fluid space within a tank
3.1.4
explosion pressure shockproof tank
tank which is designed to withstand an internal explosion without leakage; permanent deformations are permissible
Note 1 to entry: Where the atmospheric pressure is 1 bar the maximum explosion pressure is measured at 10 bar (abs.)
3.1.5
single skin tank
impermeable containment consisting of a tank of single containment
Note 1 to entry: They also constitute the inner tank of a double skin tank.
3.1.6double skin tank
impermeable self contained tank with outer skin welded around the inner tank
prEN 12285-1:2014 (E)
3.1.7
operating pressure (P )
o
pressure inside the tank above the liquid during operating conditions
3.1.8
test pressure (P )
t1
pressure to which the tank or compartment is subjected for testing
3.1.9
interstitial test pressure (P )
t2
Effective pressure at the bottom of the tank to which the interstitial space between the skins is subjected for testing.
Note 1 to entry: It is only applicable for double skin tanks.
3.1.10
nominal volume
storage capacity for which the tank is designed
3.1.11
actual volume
volume which is equal to or greater than the nominal volume
Note 1 to entry: The safe working capacity of the tank should usually not exceed 97 % of the nominal volume in normal
operating temperatures.
3.2 Symbols and abbreviations
For the purpose of this standard the following symbols apply:
Dimensions in mm
d External nominal diameter of the tank
d Inside diameter of the manway
d Diameter of the manway cover
h Length of the straight flange of the dished end
k Pitch circle diameter of manway bolts
p
l Length of the compartment of a tank without dished ends
c
l Overall length of the tank
o
l Length of the tank without dished ends
z
p test pressure
t
r Crown radius of dished ends
r Knuckle radius of dished ends
r Knuckle radius of the outer dished end
s Nominal thickness of inner skin and inner dished ends
s Interstitial space
prEN 12285-1:2014 (E)
s Nominal thickness of outer skin
s Nominal thickness of outer dished ends
s Nominal thickness of compartment dished ends
s Nominal thickness of manway flange and cover
s Plate thickness of manway body
γ incline angle for T-joint welding
Tank type S       Tank type D
(single skin)       (double skin)

Key
1 nozzle detail see figure 3
2 example for stiffening ring see figure 4
3 lifting lug
Figure 1 — Example of tank symbols
4 Product characteristics
4.1 General
The tank material shall be appropriate in relation to the storage media, Guidelines on material specifications in
relation to storage media is provided in Annex B
4.2 Welding
4.2.1 Types of joints
The welding related to the different types of joint is given in Table 2.The types of welded joints shall be in
accordance with Table 2. All internal attachments shall be continuously welded.
prEN 12285-1:2014 (E)
Table 2 — Types of welded joints
No Types of joints Class of tanks and liquid (liquid touched wall)
applicable welding
1 Square butt joint Plate misalignment shall not exceed 0,3 s
respectively 0,3 s or 2 mm
For all classes
2a Joggled butt joint For class A and hydro¬carbon liquids
For double and single skin tanks

Not permissible with inner coating
2b Joggled butt joint For class A, B and C

3a Overlap joint For class A, B and C
For outer skin
a = 0,7 s
3b Overlap joint For class A, B and C
For outer skin
a = 0,7 s
4 Fillet weld in T-joint For class A, B and C
For nozzles in the outer skin
a = 0,7 s
min
s : thickness of the thinner plate
min
5 Fillet weld (full penetration) in T-joint For class A, B and C
For manholes, nozzles and inspection covers
γ = 45°
prEN 12285-1:2014 (E)
No Types of joints Class of tanks and liquid (liquid touched wall)
applicable welding
6 Double fillet weld in T-joint For class A, B and C
For manholes, nozzles and stiffening rings
a = 0,7 s
min
s = thickness of the thinner plate
min
7a Fillet weld in overlap joint For class A, B and C
For compartment dished ends with knuckle radius

7b Fillet weld in overlap joint For class A, B and C
For compartment dished ends with knuckle radius
Not permissible with inner coating

8 Butt joint For class A and B
For compartment dished ends with knuckle radius
Not permissible with inner coating

9 Double fillet weld in T-joint For class A and B
For compartment dished ends without knuckle radius
a = 0,7 s
prEN 12285-1:2014 (E)
No Types of joints Class of tanks and liquid (liquid touched wall)
applicable welding
4.2.2 Shell plate arrangement
Cross seams shall not be used. Longitudinal welds shall not be used in the bottom half of the tank.
Shell plate joints shall be offset, having a minimum distance e of five times the wall thickness but not less than 25
mm.
Key
e minimum distance
Figure 2 — Shell-plate arrangement for inner and outer skin
4.2.3 Consumables
All welding rods/wires and other consumables shall be compatible with the basic material.
4.2.4 Interstitial space
The interstitial space gap should be as small as practically possible but suitable for the leak detection system to
function.
There shall be at least two sockets for the leak detection system and these shall be located at the highest point of
the interstitial space.
The interstitial space shall be connected to a leak detection system in order to monitor the integrity of the tank
permanently; the leak detection systems shall fulfil the requirements of e EN 13160–1 to –7.
4.3 Additional requirements
4.3.1 Roundness of the tank
When tested in accordance with 5.6.1, the maximum out of roundness of the completed tank after manufacture
shall not exceed 1,5%.of the diameter.
prEN 12285-1:2014 (E)
4.3.2 Manways and inspection covers
The tanks shall be equipped with at least one inspection cover per compartment. In cases where inspection covers
are not allowed, the tanks shall have one manway of at least d = 600 mm. No part of a compartment shall be more
than 10 m from a manway. Single skin tanks shall always have a manway.
Manway (inspection covers, nozzles) shall be of set-through or set-on-type. Nozzles and flanges shall either be
welded inside and outside, or by full penetration.
For the dimensions of the manways and their components see Table 3.
Gaskets shall be provided and shall be suitable for their purpose.
Table 3 — Dimensions of manway components
Inside Plate Diameter Pitch Bolt hole Flange thickness and Bolts
diameter thickness of cover circle diameter cover thickness
of diameter
manway
body
d s d K s Thread Number
2 7 3 p 6
size
mm mm mm mm mm mm
Class A Class B
and C
a
600 6 720 680 12 16 32
800 7 920 880 18 12 20 M16 44
b
1000 7 1120 1080 — 20 48
a
If a manway is required and no specification is given by the purchaser this diameter shall be used.
b
For tanks of class C inside diameters of the manway (d2) exceeding 800 mm is not permitted.

Instead of the manway covers shown in the Figure 3 and dimensioned in Table 3, pressed parts of manway
(Covers and/or nozzles) may be used in class A tanks with a plate thickness at least equal to the thickness of the
inner tank s . A ribbed or pressed manway cover shall withstand the test pressure P .
1 t
The gasket shall be in one piece and as wide as the flange.
Inspection covers for tanks of class A with d ≤ 1250 mm and tanks of classes B and C with d ≤ 1000 mm. The
1 1
diameter of the inspection cover shall not be larger than 300 mm and not smaller than 120 mm, and the thickness
of the inspection cover shall be equal to the minimum thickness of the inner tank.
4.3.3 Structural bolts
Structural bolts used shall be in accordance with EN ISO 898-1, with a property class being at least 4.6. The
material chosen shall be compatible with the tank material.
4.3.4 Tank fittings, pipes and nozzles
Materials used for the fabrication of tank accessories if welded to the tank shall be compatible with the tank
material .
prEN 12285-1:2014 (E)
All tank fittings, pipes and nozzles, shall be situated on the manway cover or above the maximum fill level of 97%
of the tank capacity in the single skin top of the tank.
For tanks of class C only the set-through manway nozzles shall be used. For set-through manway nozzles a vent of
a minimum of 10 mm diameter or equivalent opening shall be provided in the manway neck at the highest practical
point.
A penetration of the double skin is not allowed (exception: nozzles for leak detection system). Fittings and all other
openings shall have a minimum distance of 50 mm to welded seams.

Key
1 Gasket
2 Set-on nozzle
3 Set-through nozzle
4 Vent or pressure relief device
5 Surface roughness of facing
a Connection for earthing and use for cathodic corrosion protection if required.
Figure 3 —Examples for manways
4.3.5 Lifting lugs
Each tank shall be provided with lifting lugs. The number of lifting lugs shall be at least 1 for a tank up to 20 m
nominal volume and not less than 2 above 20 m . The lug(s) shall be positioned to enable the tank to be lifted in a
horizontal position.
prEN 12285-1:2014 (E)
Lifting lugs fully welded to the tanks shall be provided in sufficient size and quantity to enable the empty tank to be
lifted.
The lifting lugs shall be provided with a lifting hole of at least 60 mm minimum diameter.
In order to prevent deformation and for maintaining integrity of the coating, a reinforcement plate shall be provided
or the lifting lug(s) shall be made of suitable size.
4.4 Mechanical resistance and stability
4.4.1 Materials for shell, dished ends and manways
The mechanical properties of the steel grade used shall be at least those of S 235 JR according to table 7 of
EN10025-2 2004
Material inspection documentation of shell plates and dished endslshall be as follows:
 for carbon steel according to EN 10025 in accordance with the requirements of 2.2 of EN 10204:2004 and
 for all other steel qualities shall be in accordance with 3.1 of EN10204
4.4.2 Wall thickness
4.4.2.1 Nominal wall thicknesses
The nominal wall thickness of the inner tank shell, outer tank shell and dished ends expressed in round millimetres
shall be at least as given in Table 4.
prEN 12285-1:2014 (E)
Table 4 —Wall thickness of inner tank shell, outer tank shell and dished ends
Dimensions in mm
Class A
Tank classes Class a Class b Class c
a
Nominal shell thickness
Nominal diameter of the inner
tank
s s s1 s3 s s s s
1 3 1 3 1 3
d
inner skin outer skin inner skin outer skin inner skin outer skin
800 up to 1600
5 3 5 3 5 3
1601 up to 2000
6 3 6 3 6 3
2001 up to 2500
6 4 7 4 7 4
2501 up to 3000
7 4 9 4 9 4
Nominal wall thickness of dished ends
Nominal diameter of the tank
s s s s s s
1 3 1 3 1 3
d
inner skin outer skin inner skin outer skin inner skin outer skin
800 up to 1600
5 3 5 3 5 3
1601 up to 2000
6 3 6 3 6 3
2001 up to 2500
6 5 7 5 7 5
2501 up to 3000
7 5 9 5 9 5
Nominal wall thickness of compartment dished ends
Nominal diameter of the tank
d
1 s s s
5 5 5
800 up to 1600
5  5 10
1601 up to 2000
6  6 14
2001 up to 2500
6  7 16
2501 up to 3000
7  9 18
4.4.2.2 Dished ends
The following dimensions shall apply: r ≤ d
1 1
r ≥ d / 30
2 1
The minimum wall thicknesses of dished ends after forming shall be at least 92 % of the nominal wall thickness
according to Table 2.
Tolerances shall be -0/+6 mm for d ≤ 2000 mm, and -0/+10 mm for d > 2000 mm based on the calculated
1 1
circumference of d .
4.4.3 Stiffening resistance
The stiffening resistance is only applicable for length above 7800 mm
Where the stiffening resistance is assured by the use of stiffening rings the number shall comply with table 5 and
be equally spaced
prEN 12285-1:2014 (E)
Table 5 — Number of stiffening rings related to length of each compartment (lC)
l in mm Number of
c
stiffening rings
7800 < l ≤ 11700 1
c
11700 < l ≤ 15600 2
c
15600 < l
c 3
Key
1 Welding for tank class B and C and for tank class A
2 Alternatively Welding for tank class A

Figure 4 —Examples for design details of stiffening rings
Apertures as shown in Figure 4 should be located at the top and bottom of the stiffening rings to allow un-
obstructed flow of liquids, vapour or gases.
For class A tanks, each stiffening ring may be intermittently welded from both sides of the stiffening rings around
the complete circumference with 150mm welded and then 150mm missed.
Alternatively stiffness resistance can be assured, by increasing the wall thickness s in Table 2 :using the following
calculation method
0,4 l + 1,4 d
c 1
s (rounded up to full mm)
1=
4.5 Internal pressure
Shall be assured by the minimum wall thickness in table 2
prEN 12285-1:2014 (E)
When tested in accordance with 5.1 and Table 8, there shall be no leakage from single skin and inner
tanks/compartments of double skin tanks and the interstitial space during the pressure testing.
4.6 Electrostatic behaviour (for fuel networks)
Not relevant
4.7 Tightness (gas and liquid)
When tested in accordance with 5.5 no leakage shall be detected
4.8 Release of dangerous substances
National regulations on dangerous substances may require verification and declaration on release and sometimes
content when construction products covered by this standard are placed on those markets. In the absence of
European harmonised test methods verification and declaration on release/content should be done taking into
account national provisions in place of use.
NOTE An infiormative data base covering European and national provisions on dangerous substances is available at the
Construction web site on Europa accessed through: http://EC.Europa.EU/enterprise/construction/cpd-ds/
4.9 Durability
The durability of the tightness is assured provided that an external protective coating is applied in accordance with the
coating manufacturer's instructions.
The minimum thickness of the external protective coatings shall be in accordance with Table 6.
Table 6 — Minimum thickness
Coating material Min. thickness
mm
Bitumen with fabric reinforcement 3
without reinforcement 5
Epoxy 0,7
Glassfibre (GRP) 2
Polyurethane 0,8
PVC 1,25
4.10 Crushing resistance
The resistance to crushing shall exceed the weight of the earth cover at 1.5 m depth.
The maximum overall length of the tank shall not exceed 6 times the nominal diameter.
The tolerance on the overall length of the tank shall be ± 1% of the real length stated by the manufacturer.
prEN 12285-1:2014 (E)
5 Testing, assessment and sampling methods
5.1 Mechanical resistance and stability
5.1.1 Materials for shell, dished ends and manways
Check and record that the steel plates used conform to the European Standards given in 4.2.1.
5.1.2 Wall thickness
Measure steel plates with a calibrated ultrasonic meter to ensure that they conform to the thickness given in Table
2/3 [4.2.2.1]
5.1.3 Welding
Visually inspect and record the tank to verify that the welds conform to Table 3 and that all internal welding is
continuous
5.1.4 Stiffening rings
Measure the tank, inspect and record to verify that stiffening rings are fitted in accordance with 4.2.4.
5.2 Load-bearing capacity
The load bearing capacity is dependent on the roundness of the tank.
The measurement of the height and width shall be taken at the end of the manufacturing process inside each
compartment of the tank in the middle of its cylinder. The greater of the two shall not exceed the smaller by more
than 1.5%.
5.3 Electrostatic behaviour (for fuel networks)
Not applicable
5.4 Tightness (gas and liquid)
Single skin and inner tanks/compartments of double skin tanks and the interstitial space shall be tested in
accordance with Table 7. No leakage shall be observed during the pressure testing.
Table 7 —Test pressure P
t
Pressure in bar
Tank class
A B C
Test Test medium
Test pressure Test pressure Test pressure
P P P
t t t
air 0,75 2,0 ---
Prototype test
liquid 0,75 2,0 10 or 11
air 0,3 0,3 ---
Leak tightness test of tank
liquid 0,75 2,0 2,0
air
0,3
Leak tightness test of interstitial
0,6 0,6
space
_____________
Liquid
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0.6
5.5 Crushing resistance
5.5.1 General
The tank shall withstand an applied vertical load of 30 kN/m without deforming more than 1.5% of the diameter of
the tank. IIf the values in Table 4 are used, calculations have proven that tanks withstand a vertical load equal to
1.5 m of earth cover without crushing.
5.5.2 Manways and inspection covers
Visually inspect to confirm that the tank conforms to the requirements of 4.9.2.
5.5.3 Structural bolts
Visually inspect to confirm that the tank conforms to the requirements of 4.9.3.
5.5.4 Tank fittings, pipes and nozzles
Visually inspect to confirm that the tank conforms to the requirements of 4.9.4.
5.5.5 Lifting lugs
Visually inspect to confirm that the tank conforms to the requirements of 4.9.5.
5.5.6 Durability
Before leaving the workshop the external coating of each and every tank should be submitted to a high voltage
(holiday) test in order to prove its integrity. The minimum test voltage is given in Table 8.
NOTE Owing to possible damage during transport, storage and handling, it is essential that this test is repeated on the site
by the installer immediately before lowering the tank into the pit.
Table 8 —External coating - minimum thickness and minimum test voltage
Coating material Min. thickness External surface coating tested to the
following minimum test voltage
mm V
Bitumen with fabric reinforcement 3 14 000
without reinforcement 5 20 000
Epoxy 0,7 6 000
Glass fibre (GRP) 2 15 000
Polyurethane 0,8 6 000
PVC 1,25 10 000
NOTE The minimum test voltages indicated are related to the minimum thickness mentioned in this table. If the thickness is increased, the voltages
should also be increased. Coatings can be tested at higher voltage than indicated.

prEN 12285-1:2014 (E)
6 Assessment and verification of constancy of performance (AVCP)
6.1 General
The compliance of workshop fabricated horizontal cylindrical single skin and double skin steel tanks for the
underground storage of flammable and non-flammable water polluting liquids with the requirements of this standard
and with the performances declared by the manufacturer in the DoP shall be demonstrated by:
 determination of the product type
 factory production control by the manufacturer, including product assessment.
The manufacturer shall always retain the overall control and shall have the necessary means to take responsibility
for the conformity of the product with its declared performance(s).
6.2 Type testing
6.2.1 General
All performances related to characteristics included in this standard shall be determined when the manufacturer
intends to declare the respective performances unless the standard gives provisions for declaring them without
performing tests. (e.g. use of previously existing data, CWFT and conventionally accepted performance).
Assessment previously performed in accordance with the provisions of this standard, may be taken into account
provided that they were made to the same or a more rigorous test method, under the same AVCP system on the
same product or products of similar design, construction and functionality, such that the results are applicable to
the product in question.
NOTE 1 Same AVCP system means testing by an independent third party [only for products covered by system 1+, 1 and 3],
under the responsibility of a notified product certification body [only for products covered by system 1+ and 1].
For the purposes of assessment, the manufacturer's products may be grouped into families, where it is considered
that the results for one or more characteristics from any one product within the family are representative for that
same characteristics for all products within that same family
NOTE 2 Products may be grouped in different families for different characteristics.
NOTE 3 Reference to the assessment method standards should be made to allow the selection of a suitable representative
sample.
In addition, the determination of the product type shall be performed for all characteristics included in the standard
for which the manufacturer declares the performance:
 at the beginning of the production of a new or modified workshop fabricated horizontal cylindrical single skin
and double skin steel tanks for the underground storage of flammable and non-flammable water polluting
liquids (unless a member of the same product range), or
 at the beginning of a new or modified method of production (where this may affect the stated properties); or
they shall be repeated for the appropriate characteristic(s), whenever a change occurs in the Workshop fabricated
horizontal cylindrical single skin and double skin steel tanks for the underground storage of flammable and non-
flammable water polluting liquids design, in the raw material or in the supplier of the components, or in the method
of production (subject to the definition of a family), which would affect significantly one or more of the
characteristics.
Where components are used whose characteristics have already been determined, by the component
manufacturer, on the basis of assessment methods of other product standards, these characteristics need not be
re-assessed. The specifications of these components shall be documented.
Products bearing regulatory marking in accordance with appropriate harmonized European specifications may be
presumed to have the performances declared in the DoP, although this does not replace the responsibility on the
prEN 12285-1:2014 (E)
workshop fabricated horizontal cylindrical single skin and double skin steel tanks for the underground storage of
flammable and non-flammable water polluting liquids manufacturer to ensure that the Workshop fabricated
horizontal cylindrical single skin and double skin steel tanks for the underground storage of flammable and non-
flammable water polluting liquids as a whole is correctly manufactured and its component products have the
declared performance values.
6.2.2 Test samples, testing and compliance criteria
The number of samples of workshop fabricated horizontal cylindrical single skin and double skin steel tanks for the
underground storage of flammable and non-flammable water polluting liquids to be tested/assessed shall be in
accordance with Table A.
prEN 12285-1:2014 (E)
Table 9 —Number of samples to be tested and compliance criteria

Characteristic No. of samples
Requirement Assessment Compliance criteria
method
[name of the [clause where requirement [number of [clause where criteria are
characteristic] is given. Usually, clause 4 [clause where the samples to be given. Usually they should
“Requirements” of the method is given] assessed] appear in clause 4
standard] “Requirements” of the
standard]
Mechanical 4.2 5.1 Each tank 4.2 new clauses to be put in
resistance and
stability
Materials for 4.2.1 5.1.1 Each tank 4.2.1
shell, dished
ends and
manways
Wall thickness 4.2.2 5.1.2 Each tank 4.2.2
Welding 4.2.3 5.1.3 Each tank 4.2.3
Stiffening rings 4.4.3 5.1.4 Each tank 4.4.3
Load-bearing 4.3.1 5.2 Each tank 4.3.1
capacity
Electrostatic not relevant not relevant not relevant Not relevant
behaviour (for
fuel networks)
Tightness (gas 4.5 5.4 Each tank 4.5 and 5.4
and liquid)
Release of 4.8 Each tank 4.8
dangerous
substances
Crushing 4.7 5.5 Each tank 4.7
resistance
Internal 4.5 5.4 Each tank class 4.5 and 5.4
pressure
Additional tests 4.9 5.7 Each tank 4.9
Roundness of 4.3.1. 5.5.1 Each tank 4.3.1
the tank
Manways and 4.3.2 5.5.2 Each tank 4.3.2
inspection
covers
Structural bolts 4.3.3 5.5.3 Each tank 4.3.3
Tank fittings, 4.3.4 5.5.4 Each tank 4.3.4
pipes and
nozzles
Lifting lugs 4.3.5 5.5.5 Each tank 4.3.5
Durability 4.9.6 5.5.6 Each tank 4.9.6

prEN 12285-1:2014 (E)
6.2.3 Test reports
The results of the determination of the product type shall be documented in test reports. All test reports shall be
retained by the manufacturer for at least 10 years after the last date of production of the Workshop fabricated
horizontal cylindrical single skin and double skin steel tanks for the underground storage of flammable and non-
flammable water polluting liquids to which they relate.
6.3 Factory production control (FPC)
6.3.1 General
The manufacturer shall establish, document
...