EN 14620-5-2006 en Design and manufacture of site built vertical cylindrical flat-bottomed steel tanks for the storage of refrigerated liquefied gases with operating temperatures b.pdf

1、BRITISH STANDARDBS EN 14620-5:2006Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0 C and p165 C Part 5: Testing, drying, purging and cool-downThe European Standard EN 14620-5:

2、2006 has the status of a British StandardICS 23.020.10g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14620-5:2006This British Standard was pu

3、blished under the authority of the Standards Policy and Strategy Committee on 29 December 2006 BSI 2006ISBN 0 580 49779 8National forewordThis British Standard was published by BSI. It is the UK implementation of EN 14620-5:2006.The UK participation in its preparation was entrusted to Technical Comm

4、ittee PVE/15, Storage tanks for the petroleum industry.A list of organizations represented on PVE/15 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with

5、a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14620-5 September 2006 ICS 23.020.10 English Version Design and manufacture of site built, vertical, cylindrical, flat-bottom

6、ed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0 C and -165 C - Part 5: Testing, drying, purging and cool-down Conception et fabrication de rservoirs en acier fond plat, verticaux, cylindriques, construits sur site, destins au stockage des gaz rfr

7、igrs, liqufis, dont les tempratures de service sont comprises entre 0 C et -165 C - Partie 5: Essais, schage, inertage et mise en froid Auslegung und Herstellung standortgefertigter, stehender, zylindrischer Flachboden-Stahltanks fr die Lagerung von tiefkalt verflssigten Gasen bei Betriebstemperatur

8、en zwischen 0 C und -165 C - Teil 5: Prfen, Trocknen, Inertisieren und Kaltfahren This European Standard was approved by CEN on 20 February 2006. 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

9、 national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version

10、in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia,

11、Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCH

12、ES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14620-5:2006: EEN 14620-5:2006 (E) 2 Contents Page Foreword. 3 1 Scope 4 2 Normative references . 4 3

13、 Terms and definitions. 4 4 Hydrostatic and pneumatic testing . 4 4.1 Hydrostatic test . 4 Table 1 Hydrostatic test requirements 5 4.2 Pneumatic test. 8 5 Drying, purging and cool-down. 9 5.1 Procedures 9 5.2 Drying. 10 5.3 Purging. 10 5.4 Cool-down 10 6 Decommissioning . 10 Annex A (informative) Co

14、ol-down of the tank 12 Bibliography . 13 EN 14620-5:2006 (E) 3 Foreword This European Standard (EN 14620-5:2006) has been prepared by Technical Committee CEN/TC 265 “Site built metallic tanks for the storage of liquids”, the secretariat of which is held by BSI. This European Standard shall be given

15、the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2007, and conflicting national standards shall be withdrawn at the latest by March 2007. EN 14620 Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel t

16、anks for the storage of refrigerated, liquefied gases with operating temperatures between 0 C and -165 C consists of the following parts: Part 1: General; Part 2: Metallic components; Part 3: Concrete components; Part 4: Insulation components; Part 5: Testing, drying, purging and cool-down. Accordin

17、g to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

18、 Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14620-5:2006 (E) 4 1 Scope This European Standard specifies the requirements for testing, drying, purging and cool-down of the refrigerated liquefied gas storage

19、tanks. This European Standards deals with the design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0 C and 165 C. 2 Normative references The following referenced documents are indis

20、pensable for the application of this European Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 14620-1:2006, Design and manufacture of site built, vertical, cylindrical, flat-b

21、ottomed steel tanks for the storage of refrigerated, liquefied gases with operating temperatures between 0C and 165 C Part 1: General 3 Terms and definitions For the purposes of this European Standard, the terms and definitions given in EN 14620-1:2006 apply. 4 Hydrostatic and pneumatic testing 4.1

22、Hydrostatic test 4.1.1 General A hydrostatic test shall be carried out. The hydrostatic test shall demonstrate that: tank is designed and constructed to contain the product (no leakage); NOTE A leakage test is not applicable for membrane tanks. Instead an ammonia test is carried out on the membrane

23、after completion of welding. An ammonia sensitive paint is applied on the weld seam on the inside of the tank. Ammonia vapour is introduced in the insulation space and in case of a leak the ammonia will react with the paint resulting in a change of colour from yellow to blue. In order to calibrate t

24、he test, reference holes are made in the membrane so that proper performance of the inspection method is ensured. After closing of all leaks, another test is carried out. The paint on the inside of the tank is removed by vacuum cleaning. For reference, the NF A 09-107 note. foundation is able to sup

25、port the tank contents. 4.1.2 Test requirements for each type of tank For the various tank types, the hydrostatic test shall be carried out in accordance with Table 1. The contractor shall prepare a specification with all the actions to be taken. The test results shall be documented. EN 14620-5:2006

26、 (E) 5 Table 1 Hydrostatic test requirements Contents Single Double Full Membrane tank containment containment containment Tank Inner tank Inner tank (type II-III steels): (type I-II steels): (type I-II steels): Ammonia, FH FH FH butane, Outer tank Outer tank propane, (type I-II steels): (type I-II

27、steels): and FH FH propylene Outer tank Outer tank Outer tank (pre-stressed conc): (pre-stressed conc): (pre-stressed conc): No test (see NOTE 2) No test (see NOTE 2) PH (see a) Tank Inner tank Inner tank (type IV steel): (type IV steel): (type IV steel): PH PH PH Ethane, Outer tank steel Outer tank

28、 steel Ethylene and (type IV steel): (type IV steel): LNG PH PH Outer tank Outer tank Outer tank (pre-stressed conc): (pre-stressed conc): (pre-stressed conc): No test (see NOTE 2) No test (see NOTE 2) PH (see NOTE 2) aIn the case of a membrane tank, the membrane cant be hydrostatically tested. To e

29、nsure that the foundation is able to support the tank contents and the tank integrity is ensured, the concrete outer tank shall be hydrostatically tested before the insulation and membrane are installed. NOTE 1 FH means Full height hydrostatic test; PH means Partial height hydrostatic test. NOTE 2 H

30、ydrostatic testing of the pre-stressed concrete outer tank is not required, see prEN 14620-3:2005, A.2. EN 14620-5:2006 (E) 6 4.1.3 Additional requirements The following additional requirements shall apply: for a full height hydrostatic test, the inner tank shall be filled to the maximum design liqu

31、id level. The same quantity of water shall be used for testing of the outer tank; for a partial height hydrostatic test of the inner tank, the test level shall be equal to 1,25 times the height of the maximum design liquid level multiplied by the density of the specified product to be stored. The sa

32、me quantity of water contained shall be used for testing of the outer tank; when outer tanks are hydrostatically tested, a suitable water barrier shall be provided to prevent that test water ingress in to the bottom insulation; care shall be taken during filling of the annular space that water level

33、s are controlled and regulated to prevent differential levels between the inner and annular spaces; hydrostatic test shall not be carried out until all welded accessories to the shell and the bottom of the tank are in place. Welding shall not be allowed after completion of the hydrostatic test; for

34、tanks which are to be insulated with perlite powder, the hydrostatic test shall be carried out before installation of the perlite powder; test level of a membrane tank shall be based on the partial hydrostatic test requirement indicated above; contractor shall ensure that the quality of the water is

35、 such that no damage to the steel/concrete can occur. 4.1.4 Quality of the water The suitability of the water for hydrostatic testing shall be demonstrated. Special attention shall be paid to possible corrosion. The following types of corrosion shall be considered: general corrosion; galvanic corros

36、ion NOTE 1 galvanic corrosion (fresh and seawater) is an electrochemical form of corrosion that can occur when a metal or alloy is electrically connected to another metal or alloy with a different electrochemical potential. Both metals should be exposed to a common electrolyte and electrical path. W

37、elding of metals can lead to dissimilar metal compositions between the weld, Heat Affected Zone (HAZ) and the plate material. The most anodic material area will corrode because of the galvanic effect with the cathodic material areas. localised corrosion (pitting, under deposit corrosion, bacterial c

38、orrosion); NOTE 2 localised corrosion will occur under circumstances that promote the formation of localised cells: 1. presence of deposits and or solids; 2. presence of sulphate reducing bacteria; 3. locations where a low oxygen content is present. EN 14620-5:2006 (E) 7 Deposits or solids, present

39、in the seawater, may settle down on the steel surface during hydrostatic testing and localised corrosion cells may develop. This can lead to high corrosion penetration rates. NOTE 3 The main corrosion concerns, when using seawater during hydrostatic testing of 9 % nickel steel tanks, are: 1) galvani

40、c activity between plate material, weld and HAZ; 2) when soils/deposits are present in the seawater, localised corrosion when cells can develop; 3) effect of sulphate reducing bacteria resulting in sour “corrosive” environment and possible formation of hydrogen; 4) protection of stainless steel inte

41、rnal components and exposed flange gasket surfaces; 5) removal/prevention of dried mineral deposits resulting from draining of sea water. The need for cathodic protection should be investigated to avoid galvanic corrosion and to reduce general corrosion. Cathodic protection promotes the cathodic rea

42、ction, which in de-aerated conditions (under deposits) generates hydrogen and therefore increases the risk of hydrogen stress cracking, if H2S is present at the same time. The cathodic protection system shall be designed so that the risk of hydrogen embrittlement is avoided. If the required water qu

43、ality cant be achieved then alternative test methods utilizing suitable inhibitors shall be considered. In view of discharge of the water, the environmental impact shall be investigated. 4.1.5 Conditions of implementation Before the start of the test, the tank shall be cleaned. Any spatter and slag

44、shall be removed from the welds, and all materials, objects or temporary installations used during its construction, shall also be removed. A permanent or temporary pressure relief system shall be used during the test. The pressure relief system shall have sufficient capacity to ensure that the inte

45、rnal positive and negative test pressures do not exceed those specified in the design of the tank. A water column gauge shall also be used to measure the pressure. NOTE A corrosion inhibitor may be required. 4.1.6 Examination during filling 4.1.6.1 Peripheral level check Before filling, the followin

46、g markers shall be installed on the outer surface of the tank: four markers for tanks with a diameter 10 m; eight markers for tanks with a larger diameter. Markers shall also be installed on the inner tank shell, in double and full containment tank systems, so that settlement of the inner tank can b

47、e monitored simultaneously with that of the outer tank. The markers shall be of such a type that they remain visible/usable after the tank is painted. EN 14620-5:2006 (E) 8 The settlement of the tank shall be monitored during the filling and emptying of the tank. As a minimum, this shall be done whe

48、n the tank is half full, three-quarters full and full. 4.1.6.2 Bottom surface level check For tanks, where bottom differential settlements of more than 30 mm can be expected (e.g. tanks with raft foundation), provisions shall be provided so that the settlements in the centre of the tank can be monit

49、ored. NOTE An inclinometer may be used. 4.1.7 Filling The rate of filling shall be determined based on water/equipment availability and subsoil conditions. The full water load shall be maintained for at least 24 h. During the test, a visual inspection of the shell welds for possible leakage shall be carried out. The tightness of all welded joints above the test water level of an open top tank shall be inspected by vacuum box testing. The anchors, if present, sh