The serious corrosion problem at low temperature could be found in atmospheric-vacuum distillation unit, especially in the atmosphere overhead condenser.
常减压装置存在较为严重的低温位腐蚀问题，尤其是常压塔顶冷凝器腐蚀问题更为严重。
2
With increasing acid value, density, salt and sulfur in Liaohe Crude, The HCI-H2SO4-H2O corrosion in overhead condensing system of atmospheric-vacuum unit was deteriorating.