# Standard SOP Compilation Outline for Operation, Inspection and Maintenance of Four Types of Anti-Corrosion Heating Tubes in Fermentation Workshops ## General Part: Universal SOP General Provisions Applicable to All Four Heating Tube Types ### 1 Purpose and Scope 1.1 Standardize the whole-process operation, patrol inspection, periodic maintenance, fault disposal, idle storage and scrapping management of heating tubes; eliminate human-induced equipment damage and fermentation batch quality risks. 1.2 Cover four categories: 316L stainless steel heating tubes, pure titanium heating tubes, quartz heating tubes, PFA coated heaters; applicable to biopharmaceutical sterile fermentation, food fermentation, chemical intermediate production and laboratory test tank posts. 1.3 Comply with factory GMP quality system requirements, all operation records support full traceability audit. ### 2 Post Responsibility Division 2.1 Production operators: Daily startup/shutdown operation, routine patrol inspection, real-time parameter recording, basic pipeline cleaning, abnormal alarm first report. 2.2 Equipment maintenance technicians: Periodic disassembly inspection, calibration of sensors and interlock systems, accessory replacement, fault troubleshooting, offline protective treatment, annual overhaul. 2.3 Quality QA personnel: Regular spot check of equipment archive integrity, medium impurity sampling verification, GMP compliance confirmation of heating equipment operation status. 2.4 Equipment management engineer: SOP version updating, preventive maintenance plan scheduling, supplier technical docking, full-life-cycle performance evaluation, material selection optimization. ### 3 Universal Safety Operation Rules 3.1 Before any disassembly and maintenance, cut off heating power, close inlet and outlet valves, empty medium and residual cleaning liquid, and implement locking tag-out (LOTO). 3.2 Prohibit modifying PLC interlock threshold parameters without written approval from equipment engineers. 3.3 Special matched tools must be used for maintenance; metal hard tools are prohibited for titanium, quartz and PFA equipment. 3.4 After all maintenance operations, full-load trial run of at least one batch is required, and records can be signed off only if no abnormality exists. 3.5 All inspection, maintenance and fault disposal shall be recorded on standardized forms with date, operator signature and supporting test photos. ## Chapter 1 SOP for 316L Stainless Steel Heating Tube ### Section 1 Startup, Operation and Shutdown Standard Operation Steps 1. Pre-start inspection: Check exhaust valve smoothness, alkali temperature interlock normal indication, no obvious rust on tube surface, PTFE isolation strip intact between tube bundle and carbon steel support. 2. Gradual temperature rise operation: Heating rate controlled ≤0.8℃/min; avoid rapid temperature rise causing weld thermal stress crack. 3. Real-time parameter monitoring items: Medium chloride concentration, alkali cleaning peak temperature, heating power fluctuation, exhaust pressure. 4. Standard shutdown process: Stop heating → full CIP cleaning → dry air blow-dry pipeline interior → close blind plates for long-term idle standby. ### Section 2 Daily Routine Patrol Inspection Items (Recorded per Shift) 1. Check for rust spots, local discoloration and scale accumulation on tube bundle outer wall. 2. Confirm alkali interlock sensor display is normal, no manual shielding of alarm function. 3. Listen to exhaust pipeline for abnormal air blockage noise; clean sediment if exhaust is unsmooth. 4. Record real-time heating power to judge scaling growth trend. ### Section 3 Periodic Maintenance SOP (Standard Cycle Execution) 1. Monthly: Online CIP acid descaling, exhaust valve disassembly cleaning, chloride data statistical analysis. 2. Bi-monthly: Full ultrasonic wall thickness scanning, weld visual inspection, supplementary local passivation for corroded areas. 3. Quarterly: Full tube bundle light pickling passivation, interlock sensor calibration, support isolation strip replacement. 4. Semi-annual: Partial disassembly internal cleaning, weld microcrack magnified inspection. 5. Annual: Full hydraulic pressure tightness test, all aging PTFE gasket replacement, residual service life evaluation. ### Section 4 Common Fault Disposal SOP 1. Weld rust pitting: Isolate tube bundle → wall thickness test → light corrosion: local passivation; severe penetration: apply for replacement. 2. Continuous power rise due to scaling: Trigger automatic acid circulation descaling; repeat twice if effect is poor, then disassemble for offline cleaning. 3. Alkali over-temperature alarm: Immediately cut off heating power, extend clear water flushing duration, calibrate interlock sensor. ### Section 5 Long-Term Idle Storage Protection SOP 1. Post-shutdown treatment: Complete acid-base cleaning, dry air thorough blow-dry, supplementary weld passivation. 2. Sealed storage: Blind plate seal all ports, wrap waterproof film with desiccant, place on plastic support frame. 3. Regular inspection every two months; re-passivation and re-sealing every six months for idle over half a year. ## Chapter 2 SOP for Pure Titanium Heating Tube ### Section 1 Startup, Operation and Shutdown Standard Operation Steps 1. Pre-start inspection: Fluoride detector zero calibration, aeration equipment standby ready, all titanium-carbon steel contact positions covered by intact PTFE isolation sleeves, no scratch on tube surface. 2. Startup sequence: Turn on aeration system first → start feeding after dissolved oxygen ≥8mg/L → segmented heating. 3. CIP cleaning mandatory requirement: Aeration device keeps running throughout the whole cleaning cycle for oxygen-rich water circulation. 4. Shutdown protection: After cleaning, run 30-minute oxygen-rich water circulation before emptying pipeline for standby. ### Section 2 Daily Routine Patrol Inspection Items (Recorded per Shift) 1. Fluoride online detector real-time reading, no trace fluoride alarm. 2. Tube surface observation for milky white matte etching traces and large-area scratches. 3. Tank bottom outlet check for rust sediment falling from isolation sleeves. 4. Record surface electrochemical potential fluctuation range. ### Section 3 Periodic Maintenance SOP (Standard Cycle Execution) 1. Monthly: Aeration equipment maintenance, fluoride detector data archiving, exhaust sensor cleaning. 2. Quarterly: Full surface potential scanning, all isolation sleeve aging inspection and replacement, fluoride pipeline interlock simulation test. 3. Semi-annual: 30-minute full-bundle oxygen-rich water circulation passivation, pipeline rust sediment thorough flushing. 4. Annual: Hydraulic tightness test, offline enhanced passivation for low-potential tube bundles, full isolation accessory renewal. ### Section 4 Common Fault Disposal SOP 1. Milky white fluoride etching: Test fluorine content of medium, cut off fluoride source; slight etching: oxygen-rich water circulation repair; severe uniform wall thinning: replace tube bundle. 2. Rust sediment pollution: Stop operation, fully flush tank and pipeline, replace all damaged PTFE isolation sleeves. 3. Continuous low potential value: Check aeration system for failure, arrange offline enhanced passivation treatment. ### Section 5 Long-Term Idle Storage Protection SOP 1. Pre-storage cleaning: Oxygen-rich purified water full flushing, thorough blow-dry to avoid residual water film. 2. Storage zoning: Independent fluorine-free warehouse, soft plastic scratch-proof wrapping, nylon support placement. 3. Bi-monthly visual inspection; three-month idle equipment requires oxygen-rich water recirculation re-protection before re-sealing. ## Chapter 3 SOP for Quartz Anti-Corrosion Heating Tube ### Section 1 Startup, Operation and Shutdown Standard Operation Steps 1. Pre-start inspection: All rubber shock absorption pads fastened, alkali pipeline mechanical interlock in locked state, heating rate limiter parameter normal. 2. Startup control: Heating rate strictly limited ≤0.4℃/min, prohibit rapid temperature rise to avoid thermal shock. 3. Flow control: Circulating pump frequency adjusted to keep flow velocity ≤0.6m/s, reduce liquid impact vibration. 4. CIP restriction: Alkali liquid supply valve interlock forced closed; only dilute acid and neutral disinfectant can circulate. 5. Shutdown: Stop heating, natural cooling to room temperature before emptying pipeline medium, avoid sudden cold shock. ### Section 2 Daily Routine Patrol Inspection Items (Recorded per Shift) 1. Light transmission quick inspection for tiny cracks and surface frosting. 2. Support bracket vibration check, no loose shaking of tube bundle. 3. Monthly mandatory alkali interlock forced shutdown simulation test record. 4. Heating rate and pump flow velocity parameter real-time recording. ### Section 3 Periodic Maintenance SOP (Standard Cycle Execution) 1. Bi-weekly: Full light transmission crack scanning inspection, shock pad fastening check. 2. Monthly: Heating rate controller calibration, pump flow frequency adjustment, soft sponge surface cleaning. 3. Quarterly: All aging damping rubber replacement, low-pressure water tightness test. 4. Semi-annual: Alkali interlock valve full overhaul, unified sorting and scrapping of frosted and cracked quartz tubes. 5. Annual: Complete disassembly light transmission re-inspection, replace all plastic thread protective caps and foam buffers. ### Section 4 Common Fault Disposal SOP 1. Tube rupture: Instant power-off and valve isolation, fully drain and discard contaminated medium, replace complete shock absorption assembly and new quartz tube. 2. Surface permanent frosting: Circulate dilute acid neutralization; frosting coverage over 30% directly scrap tube bundle. 3. Abnormal vibration: Replace aging shock pads, fasten supports, reduce pump flow velocity. ### Section 5 Long-Term Idle Storage Protection SOP 1. Pre-storage cleaning: Soft sponge wipe clean, fully drain liquid, remove aging shock pads. 2. Shockproof packaging: Single tube wrapped with thick bubble wrap, placed in foam-lined wooden box, stacked with limited layers in low-vibration constant temperature warehouse. 3. Monthly packaging deformation and scratch inspection; three-month idle equipment needs full light transmission re-inspection before reuse. ## Chapter 4 SOP for PFA Coated Heater ### Section 1 Startup, Operation and Shutdown Standard Operation Steps 1. Pre-start inspection: Pipeline front solid particle filter intact, temperature interlock sensor normal display, no obvious blistering and peeling on coating surface. 2. Operation temperature limit: Long-term continuous medium temperature controlled below 90℃, avoid long-term operation close to 95℃ interlock threshold. 3. Post-CIP mandatory program: After high-temperature cleaning, the system automatically runs 40-minute slow cooling, manual skipping is prohibited. 4. Disinfection control: Hydrogen peroxide concentration reduced by half to slow coating oxidative aging. ### Section 2 Daily Routine Patrol Inspection Items (Recorded per Shift) 1. Coating surface visual scan for yellowing, blisters and shallow scratches. 2. Medium continuous operating temperature curve recording, no long-term over-temperature alarm. 3. Filter cartridge blockage check, timely replacement if flow resistance rises abnormally. 4. Confirm slow cooling program is automatically executed after each CIP cycle. ### Section 3 Periodic Maintenance SOP (Standard Cycle Execution) 1. Monthly: Coating surface full visual scan, filter cartridge replacement, temperature data statistical analysis. 2. Bi-monthly: Temperature interlock sensor calibration, self-cleaning filter function test. 3. Quarterly: Multi-point coating thickness measurement, sharp metal support liner replaced with soft plastic pads. 4. Semi-annual: Coating adhesion sampling test, count blister damage area, arrange overall replacement for damage ratio over 5%. 5. Annual: Hydraulic tightness test, all soft plastic sealing plug renewal, over-temperature fault data sorting and parameter optimization. ### Section 4 Common Fault Disposal SOP 1. Coating blistering and yellow aging: Calibrate temperature interlock, enforce slow cooling program; large-area peeling directly replace heater. 2. Penetrating scratch exposing substrate: Activate filter self-cleaning, replace filter element; mandatory overall replacement of damaged heater to prevent rust leakage. 3. Continuous excessive power consumption: Scan coating blister coverage, arrange planned replacement if area exceeds 5%. ### Section 5 Long-Term Idle Storage Protection SOP 1. Pre-storage treatment: Low-flow soft water flush abrasive particles, normal temperature dry air blow-dry, prohibit hot air drying. 2. Anti-scratch storage: Wrapped with soft non-woven fabric, sealed with plastic soft plugs, horizontally placed on plastic buffer pads, away from high-temperature heat sources and strong oxidants. 3. Bi-monthly unpacking coating inspection; four-month idle equipment needs re-flushing and re-sealing before reuse. ## Chapter 5 Supporting Auxiliary SOP Attachments (Unified for Four Heating Tube Types) ### Attachment 1 Equipment Fault Emergency Disposal SOP Standardized process of alarm discovery → power-off isolation → sampling retention → fault positioning → disposal implementation → post-disposal trial run → fault record filing, including emergency material list for each heating tube type. ### Attachment 2 Annual Preventive Maintenance Execution SOP Monthly/quarterly/semi-annual/annual maintenance task checklist, maintenance record form template, maintenance after-trial run confirmation sheet, residual service life evaluation table. ### Attachment 3 Equipment Long-Term Idle Storage and Reactivation SOP Unified cleaning, drying, sealing, periodic inspection and pre-production re-inspection operation steps for all heating tube materials. ### Attachment 4 Equipment Scrapping Disposal SOP Judgment criteria for scrapping, scrapping application approval process, classified disposal requirements for stainless steel scrap, titanium fluorine-containing waste, quartz solid waste and PFA fluorine hazardous waste, waste transfer record filing rules. ### Attachment 5 GMP Record Archiving Management SOP Standard requirements for all patrol, maintenance, test and fault records, dual storage of electronic and paper documents, archive retention period regulation, audit quick retrieval catalog preparation requirements. ## Chapter 6 SOP Version Management and Training Requirements 1. Version upgrade trigger conditions: Working condition transformation, equipment material replacement, major fault recurrence, GMP supervision standard update; version number revised and distributed uniformly by equipment department. 2. Training implementation: All operators and maintenance technicians must pass written and practical assessment before independent post operation, training records archived into personal post files. 3. Regular SOP re-training: Organize full staff retraining every six months, focus on differentiated forbidden operation items of four heating tube materials to reduce human-induced equipment failure. ## Summary This SOP compilation outline distinguishes differentiated operation, inspection and maintenance specifications for four heating tubes based on their unique corrosion failure, structural damage and aging mechanisms. Each set of independent SOP clarifies post operation steps, patrol focus, periodic maintenance cycle, fault disposal logic and idle protection standards, matched with supporting emergency, maintenance, storage, scrapping and archive management auxiliary procedures. Full implementation of standardized classified SOP can effectively standardize frontline staff operation behaviors, reduce accidental equipment damage caused by non-standard operation, stabilize long-term safe and low-loss operation of fermentation heating systems, and ensure all operation and maintenance records fully meet GMP audit traceability requirements.
