The issue of extra-high-grade corrosion protection for buried oil tanks
Thread Content
One pressure vessel manufactured by our company is an underground oil tank. The requirement for the outer surface coating as specified in the design drawings is a super-high-grade petroleum asphalt anti-corrosion paint, in accordance with the standard SH3022-2011. I checked the standard requirements for anti-corrosion treatment of extra-strength petroleum asphalt; in addition to the asphalt primer, 5 coats of asphalt and four layers of glass cloth are also required. As for asphalt primers, it’s not too complicated – applying asphalt requires heating it first. Nowadays, environmental regulations are very strict, and it is said that this method of using petroleum asphalt for corrosion protection is on the verge of being phased out. I’m not sure if this is true Additionally, if we use the extra-high strength epoxy coal tar pitch process, it is essential to ensure that the grounding electrode is not exposed; is it necessary to apply the material several additional times on top of the extra-high strength layer?
The anti-corrosion technique involving multiple layers of oil and fabric is indeed rare these days, and the preparation of underground tanks is also changing.
We don’t need three oils and four cloths anymore, right! All use SF oil tanks; Sinopec and CNPC both use double-wall oil tanks.
It is no longer allowed to produce asphalt for anti-corrosion purposes; instead, epoxy coal tar pitch paint is used as a substitute
Currently, Sinopec and CNPC are upgrading their gas stations, using SF double-layer oil tanks for that purpose
Also, the underground oil tanks at regular gas stations are not designed as pressure vessels; they operate at atmospheric pressure