# Fermentation Heating Tube Anti-Corrosion Third-Party Testing & Laboratory Analysis Specification ## Preface This specification supports the full anti-corrosion document system ranging from Doc.33 to Doc.114. It standardizes sampling standards, third-party testing commissioning processes, laboratory item detection rules, report review, result application and archive management for heating tube corrosion testing, medium ion analysis, material performance inspection and waste liquid composition monitoring. It ensures objective, authoritative test data as the core basis for equipment assessment, process adjustment and system optimization, making up for the limitation of on-site rapid detection accuracy. Testing items are divided into four core categories with fixed sampling cycles. First, metal material corrosion testing: wall thickness loss measurement, pitting depth detection, intergranular corrosion inspection and coating integrity test for stainless steel, titanium and PFA heating tubes, sent to third-party institutions every 12 months. Second, medium ion laboratory analysis: chloride, fluoride, acid-base ion concentration and heavy metal residue detection, sampling monthly especially before and after medium switching and pickling cycles. Third, auxiliary component performance testing: gasket aging resistance, pipeline lining anti-corrosion durability and filter element impurity interception capacity, tested semi-annually. Fourth, waste liquid environmental & corrosive composition analysis of pickling waste and discharged flushing fluid, sampled quarterly to avoid secondary pipeline corrosion from unqualified discharge. Uniform on-site sampling specifications are strictly enforced. Sampling points are fixed at heating tube inlet, outlet and stagnant dead-angle auxiliary pipelines to reflect the actual long-term operating environment of the equipment. Sampling containers must be dedicated corrosion-resistant sealed vessels, cleaned with pure water and dried before use to avoid cross-contamination distorting test values. Operators record sampling time, production batch, medium type, equipment serial number and on-site real-time monitoring instrument readings synchronously on the sampling sheet, with dual signatures of patrol staff and maintenance technicians. Random sampling without marked information is prohibited. Standard commissioning and inspection workflow is formulated. The equipment management department sorts sampling samples together with a test work order, clearly listing required detection indicators, testing standards and data delivery deadlines before submitting to qualified certified third-party laboratories. During testing, technical personnel maintain communication with the testing institution; if abnormal extreme data appears in preliminary feedback, on-site resampling verification shall be arranged immediately to eliminate sampling operation errors. After receiving the official stamped test report, equipment supervisors conduct item-by-item review to compare laboratory data with on-site online monitoring records, marking inconsistent data for root cause analysis. Hierarchical disposal standards for test results are defined. If all indicators meet safe threshold standards, the equipment continues normal operation and the report is filed as regular baseline data. If partial indicators exceed warning limits without penetration risks, enhanced on-site patrol frequency and shortened self-test cycles are implemented, with resampling scheduled within one month. If severe corrosion, harmful ion over-limit or material performance attenuation beyond safety standards is confirmed, the heating tube is classified as Grade B limited monitoring or Grade C mandatory scrapping per the service life assessment specification; relevant pickling parameters, medium circulation processes and pipeline layout schemes are revised accordingly. All sampling registration forms, commissioning application documents, original third-party test reports, data comparison analysis sheets and resampling verification records adopt dual electronic and paper archiving. Test result trend statistics are integrated into monthly anti-corrosion data analysis and quarterly system review meetings. Universal material or process defects reflected in batch test reports will trigger formal document revision and factory-wide targeted training. This specification establishes an authoritative off-site data verification channel for the whole anti-corrosion system, forms a two-layer data guarantee combining real-time online monitoring and professional laboratory testing, and completes the full-data closed-loop management of fermentation heating tube anti-corrosion.
