Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of liquefied natural gases - Part 5: Testing, drying, purging and cool-down
Design and Manufacture of Site Built, Vertical, Cylindrical, Flat-bottomed Steel Tanks for the Storage of Liquefied Natural Gases — Part 5: Testing, Drying, Purging and Cool-down
1 Scope
This part specifies the requirements for testing, drying, purging and cool-down of the liquefied natural gas (LNG) storage tanks.
This part is applicable to the design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of liquefied natural gases with operating temperatures between 0 °C and -165 °C.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 26978.1-2011 Design and Manufacture of Site Built, Vertical, Cylindrical, Flat-bottomed Steel Tanks for the Storage of Liquefied Natural Gases — Part 1: General
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 26978.1-2011 apply.
4 Hydrostatic and Pneumatic Testing
4.1 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 ‘a(chǎn)mmonia test’ is carried out on the membrane 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 the 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 09-106 note.
— foundation is able to support 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.
Foreword II
1 Scope
2 Normative References
3 Terms and Definitions
4 Hydrostatic and Pneumatic Testing
4.1 Hydrostatic test
4.1.1 General
4.1.2 Test requirements for each type of tank
4.1.3 Additional requirements
4.1.4 Quality of the water
4.1.5 Conditions of implementation
4.1.6 Examination during filling
4.1.7 Filling
4.2 Pneumatic test
4.2.1 Pressure test
4.2.2 Negative pressure test
4.2.3 Empty checks
5 Drying, Purging and Cool-down
5.1 Procedures
5.2 Drying
5.3 Purging
5.4 Cool-down
6 Decommissioning
Annex A (Informative) Cool-down of the Tank
Annex NA (Informative) Technical Deviations between this Part and EN 14620-5:2006 and Their Justifications
Bibliography
