Why do pipeline systems leak easily after chemical cleaning?

Theoretically, cleaning agents are not highly corrosive to welds.

The chemical cleaning process essentially involves introducing special chemical cleaners with corrosive or stripping properties into a container or pipeline in order to clean the pipeline. When selecting a formula for a cleaning agent, it is necessary to understand and evaluate the material and surface properties of the containers and pipelines, in order to ensure effective cleaning and protection of the inner walls of these pipelines; this can be a challenging task. Professional cleaning service providers should possess considerable experience and skill, enabling them to protect containers and pipelines while ensuring the areas to be cleaned are thoroughly cleaned. However, for certain joints, flanges, valves in containers or pipelines, as well as components and equipment made of materials different from those of the pipelines or containers, failure to provide effective protection for these parts or to remove them before cleaning may cause damage after cleaning. It is also possible that leaks occur after the scale or corrosion products that previously served to seal things up are removed. A comprehensive evaluation may make it easier to identify the problems.

Indeed, that is the case, especially for professional cleaning service providers. However, the evaluation and communication prior to cleaning, as well as the actual cleaning process, may lead to subpar cleaning results or over-cleaning due to some unforeseen circumstances.

Improper selection of cleaning agents leads to corrosion at the welds.

Chemical cleaning is a relatively specialized process that should be carried out in accordance with relevant cleaning procedures. The entire cleaning process needs to be closely monitored, with proper records kept. After cleaning, an evaluation of the cleaning effectiveness is conducted, so that a traceability process can be established in case any issues arise.

After reviewing your question, the summary is as follows: 1. When equipment and pipelines become scaled, corrosion of varying degrees occurs beneath the scale. Once the cleaning solution removes the scale and carries it away through circulation, the corroded areas may leak due to the lack of scale protection； 2. The original weld areas of the equipment and pipelines contained sand holes or small cracks; after scaling occurred, these areas became blocked. There was no leakage during normal operation, but once the hard deposits were removed through cleaning, the original sand holes and cracks reappeared, causing leakage ； 3. The cleaning solution is quite corrosive; no corrosion inhibitor was added during the cleaning process, or the amount of inhibitor used was insufficient, resulting in excessive cleaning of the equipment and pipelines. Since the weld areas are relatively weak points, leaks occur as a result ； 4. No proper communication was held with the client prior to cleaning, and the cleaning process was not properly planned; as a result, the cleaning solution accumulated in certain sections of the pipeline for an extended period without being circulated. The high concentration of the cleaning solution led to excessive corrosion ； 5. The materials used for cleaning equipment and pipelines were not considered carefully; for example, using chlorine-containing cleaners on stainless steel can lead to increased corrosion ； 6. During the cleaning process, inadequate monitoring was carried out; the excessive level of iron ions in the cleaning solution was not detected in time, resulting in excessive cleaning and weld leakage.