ADR tank special provision TT11

LPG-only carbon-steel fixed and demountable tanks may replace the periodic hydraulic test with listed NDT techniques, on request.

For fixed tanks (tank-vehicles) and demountable tanks used solely for LPG, with carbon steel shells and service equipment, the applicant may ask for the periodic hydraulic pressure test to be replaced by non-destructive testing. The listed techniques may be used alone or combined as the competent authority or inspection body thinks fit (see TT9). NDT personnel must be qualified to EN 14334:2014 or EN 12972:2018 + A1:2024. After heat is applied directly to pressure-containing parts, for example welding or cutting, a hydraulic test is still needed on top of the NDT. Welds and high-stress areas get 100 % NDT, and areas not visible from outside get an ultrasonic thickness survey from inside on a grid of at most 150 mm. Defect acceptance follows EN 14025:2023, EN 12493:2013 + A2:2020, EN ISO 23278:2015 or the acceptance standard of the NDT standard used. An unacceptable defect must be repaired and retested before any hydraulic test, and NDT results are kept for the life of the tank.

Conditions

• Techniques: EN ISO 17640:2018 ultrasonic testing of welds; EN ISO 17638:2016 magnetic particle testing with acceptance at level 2X of EN ISO 23278:2015; EN ISO 17643:2015 eddy current examination of welds; EN ISO 16809:2019 ultrasonic thickness measurement.
• Personnel qualified to EN 12972:2018 + A1:2024 or EN 14334:2014.
• Hydraulic test in addition to NDT after welding, cutting or other direct heat on pressure-containing elements.
• 100 % NDT by ultrasonic, magnetic particle or eddy current testing on shell longitudinal and circumferential butt welds, attachment, manway, nozzle and opening welds direct to the shell, and doubling-plate high-stress areas.
• Ultrasonic thickness survey from inside on a grid of at most 150 mm where the shell cannot be inspected visually from outside.
• Defect acceptance levels per EN 14025:2023, EN 12493:2013 + A2:2020, EN ISO 23278:2015 or the NDT standard's acceptance standard, regardless of the tank's original design code.
• Unacceptable defects repaired and retested; no hydraulic test without the repairs; NDT results kept for the tank's lifetime.

Note. TT11 is printed in a single (left-hand) column and runs over pages 538 to 540; its own text limits it to fixed tanks and demountable tanks. The area/NDT table on page 539 is scrambled: the row "piping and other equipment welds" cannot be assigned with certainty to either the 100 % NDT method or the ultrasonic thickness survey.

Refers to: special provision TT9; EN ISO 17640:2018; EN ISO 17638:2016; EN ISO 23278:2015; EN ISO 17643:2015; EN ISO 16809:2019; EN 12972:2018 + A1:2024; EN 14334:2014; EN 14025:2023; EN 12493:2013 + A2:2020.

Carried by 5 Table A entries

UN 1011 · UN 1075 · UN 1965 · UN 1969 · UN 1978