Horizontal cylindrical single skin and double skin tanks for the underground storage of flammable and non-flammable water polluting liquids other than for heatingand cooling of buildings
This document specifies the product characteristics and test 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) and installed in industrial processes or in petrol stations at normal ambient temperature conditions (−20 °C to +50 °C) within the following limits:
- from 800 mm up to 3 000 mm nominal diameter and;
- up to a maximum overall length of 6 times the nominal diameter;
- with an operating pressure (Po) of maximum 50 kPa (0,5 bar(g)) and minimum – 5 kPa (–50 mbar(g)) and;
- for double skin tanks with a vacuum leak detection system where the kinematic viscosity does not exceed 5 × 10−3 m2/s.