During on-site inspections of pitting corrosion leakage in heat exchangers, it is often found that the same batch of equipment has significantly different service lives in chloride-containing media. Taking the BXS-30 brazed stainless steel heat exchanger as an example, the plate material can be either 304 or 316L, with DN50 connections, a single-unit heat exchange area of 4.5 m², overall dimensions of approximately 620×280×420 mm, and a weight of approximately 48 kg. Design and selection personnel need to compare the following key points.
Key point 1: Chloride ion tolerance. Brazed stainless steel heat exchangers are not suitable for media with high chloride ion concentrations. Due to its molybdenum content, 316L outperforms 304 in pitting corrosion resistance under the same chloride ion conditions. During selection, the chloride ion concentration range in the medium should first be confirmed.
Key point 2: Structure and cleaning compatibility. This model is formed by brazing stainless steel plates, with a smooth surface, making daily cleaning convenient when used in heating tables in the food industry. However, long-term contact with strongly acidic cleaning agents should be avoided. Neutral or weakly alkaline cleaning agents are recommended, and after cleaning, the surface should be rinsed promptly and dried to maintain its condition.
Key point 3: Installation and maintenance space. With overall dimensions of approximately 620×280×420 mm and a weight of approximately 48 kg, maintenance access should be reserved. DN50 connections should match the corresponding pipe diameter to reduce additional stress.
Key point 4: Operating parameter records. It is recommended to establish a log for medium temperature, pressure, and chloride ion concentration. When the concentration approaches the material's tolerance limit, 316L should be selected or other corrosion-resistant solutions should be evaluated.
