Long-Term Storage and Idle Protection Technical Specifications for Four Types of Anti-Corrosion Heating Tubes

# Idle Protection and Long-Term Storage Technical Specifications for Four Types of Anti-Corrosion Heating Tubes ## Storage and Idling Protection Standards for 316L Stainless Steel Heating Tubes Treatment for pre-storage cleansing Fully eliminate organic fermentation scale, residual chloride medium, and alkaline cleansing residues through neutral water circulation and full CIP pickling. Blowing dry all internal and external pipe surfaces with dry sterile air after cleaning will eradicate the residual water film that causes local pitting and rust spots. To restore the chromium-rich protective film that has been damaged, perform supplementary passivation on the weld areas prior to storage. Configuration for sealed storage Seal all flange openings and pipeline connectors with stainless steel blind plates to prevent humid air and dust; wrap the complete tube bundle in waterproof plastic film that is lined with desiccant bags. To prevent contact rust, it is recommended to store tube bundles on specialised plastic support frames rather than in direct contact with the carbon steel ground. The storage warehouse must maintain a temperature between 10 and 25 degrees Celsius and a relative humidity below 60%.℃, and rigorously isolate chloride-containing raw materials, detergents, and chemical reagents. Maintenance that is conducted on a regular basis during periods of prolonged inactivity Check for surface corrosion, blind plate sealing integrity, and desiccant validity by unpacking and inspecting once every two months. Blow dry and re-seal tube bundles that have been idle for over half a year, and then re-circulate a low-concentration passivation solution for 2 hours every six months. Reactivation procedures for preproduction Conduct a surface potential detection to verify the integrity of the passivation film, remove the packaging blind plates, flush the entire pipeline with sterile purified water, and complete a wall thickness spot check before resuming production. Storage operations that are prohibited Do not store stainless steel tubes with carbon steel parts in the same warehouse without isolation. Additionally, avoid warehouse environments that contain salt mist, chlorine gas, or alkaline vapour. It is recommended that incomplete drying be skipped prior to sealing storage. ## Storage and Idling Protection Standards for Pure Titanium Heating Tubes Treatment for pre-storage cleansing Utilise purified water that is rich in oxygen to completely flush residual medium and cleansing fluid, as well as to eliminate rust sediment that has accumulated on the surfaces of carbon steel supports. Thoroughly blow dry with dry air to eliminate stagnant water; do not come into contact with any raw materials or cleaning agents that contain fluoride during the entire cleaning process. Configuration for sealed storage Install integral PTFE gaskets on all flanges and seal with blind plates to prevent metal friction scratches during storage. Wrap tube bundles with fluorine-free soft anti-scratch plastic film. Position on non-metallic nylon brackets, ensuring that they are completely isolated from fluoride chemical storage areas and carbon steel equipment. In order to prevent accidental fluorine contamination, the storage area must be completely fluoride-free and equipped with independent ventilation. Maintenance that is conducted on a regular basis during periods of prolonged inactivity It is recommended that a full surface visual inspection be conducted every two months to detect any milky white etching traces or scratch expansion. For tube bundles that have been inactive for more than three months, circulate dissolved oxygen-rich water to re-establish the TiO₂ passivation film. Subsequently, air dry the bundles and reseal them. If disassembly occurs, it is necessary to replace ageing PTFE isolation casings prior to re-storage. Reactivation procedures for preproduction Before restarting operation, remove sealing materials, conduct electrochemical potential scanning of the entire tube bundle, verify all isolation structures to ensure that there is no direct contact between titanium and carbon steel, and run a 30-minute aeration water circulation to repair the passivation film. Storage operations that are prohibited Do not store titanium tubes in warehouses that contain fluoride raw materials or fluorine-based waste. Use metal binding wires for fixed packaging. Leave residual fluoride medium inside the tube before sealing. ## Storage and Idling Protection Standards for Quartz Anti-Corrosion Heating Tubes Treatment for pre-storage cleansing To prevent artificial scratches, only clean the tube with dilute acid and neutral sterile water, drain all liquid from both inside and outside the tube, and delicately wipe the outer walls with a soft sponge without using rigid scrubbing tools. To prevent the adhesion of rubber ageing residue, it is necessary to remove all ageing vibration damping rubber pads prior to long-term storage. Configuration for hermetic storage that is shockproof Each quartz tube is individually wrapped in thick bubble wrap and subsequently placed in shockproof wooden cases that are lined with soft foam filling. In order to prevent edge chipping as a result of collisions, plastic soft caps are used to protect all thread sealing ends. Boxes must be stacked in low-vibration storage areas, away from mechanical equipment that generates strong vibration and circulating pump units, in a limited number of layers. In order to prevent the proliferation of microcracks caused by thermal stress, the temperature fluctuation range of the warehouse must be maintained at ±3℃. Maintenance that is conducted on a regular basis during periods of prolonged inactivity Perform a full light transmission crack inspection every three months for quartz tubes stored over half a year; inspect packaging foam for deformation and tube surface scratches once a month. Avoid frequently moving or transporting the box during periods of idle storage. Reactivation procedures for preproduction Gently remove the tubes, replace them with new, thick rubber shock absorption gaskets for installation, execute a full light transmission microcrack screening test and simulate low-flow circulation to verify the sealing tightness before connecting to the fermentation tank loop. Storage operations that are prohibited Stack quartz storage boxes in multiple heavy layers; place them near vibration sources or temperature mutation areas; use hard metal tools to repair the packaging; store them together with alkaline chemicals. ## Standards for Storage and Idling Protection in PFA Pre-storage cleansing treatment for coated heaters Avoid the impact of a high-pressure water gun on the coating surface by flushing residual abrasive particles and high-concentration disinfectant with low-flow soft water. Prevent the use of heated air drying, as it accelerates the ageing and brittleness of the coating. Instead, blow dry the coating with normal-temperature dry air. Before storing the fluoroplastic coating, verify that no hard particulate residue has adhered to it. Anti-scratch, constant-temperature storage configuration In order to prevent coating scratches during disassembly, it is recommended that the entire heater be wrapped in soft non-woven fabric and plastic film. Additionally, all pipeline ports should be sealed with soft plastic plugs rather than metal blind plates. Avoid bending or extruding the tube body; instead, store it horizontally on soft plastic support cushions. The temperature of the warehouse is maintained at a range of 15–30℃, maintaining it away from high-temperature heat sources such as steam pipelines and heating furnaces. Additionally, strong oxidant storage areas are isolated. Maintenance that is conducted on a regular basis during periods of prolonged inactivity Visually inspect the coating every two months to detect blistering, yellowing, and shallow scratch expansion by opening the packaging. Prevent prolonged exposure to direct sunlight during stowage. Re-flush heaters that have been inactive for more than four months with purified water that is at room temperature. Following the drying process, re-seal the heaters. Reactivation procedures for preproduction Before the formal launch, it is necessary to remove soft packaging, conduct a full coating surface scanning inspection to ensure that no new damage has occurred, install new pipeline particle pre-filters, and verify the normal operation of the temperature interlock and post-cleaning slow cooling program. Storage operations that are prohibited For long-term storage, expose PFA heaters to a high-temperature environment or direct sunlight. Use metal binding belts to secure tube bundles. Store them in a container with high-concentration hydrogen peroxide and strong oxidising chemicals. ## General Guidelines for Long-Term Storage Management 1. Storage requirement for independent zoning: Establish four storage zones that are specifically designated for various heating tube materials. These zones should be marked with clear isolation warning signs to prevent cross-contamination, scratch damage, and mixed material contact corrosion. 2. Storage label filing rule: A storage label is attached to each idle tube bundle, which captures the material type, idle start date, last cleaning treatment method, and next inspection time. All storage records are subsequently archived in the equipment full-life-cycle file. 3. Seasonal storage parameter adjustment: In humid rainy seasons, enhance dehumidification and chloride isolation measures; relocate quartz and PFA equipment from temperature mutation positions in winter and summer. 4. Control of the maximum idle time: All heating tubes must be subject to a continuous idle storage period of less than 12 months without maintenance. Equipment that has been stored for more than one year must undergo a comprehensive re-inspection and protective treatment before possible reuse. ## Executive Summary The storage and inactivity protection specifications for four heating tubes are designed to mitigate their respective storage failure risks. The storage of titanium tubes strictly prohibits fluorine pollution and maintains the passivation film through oxygen-rich water treatment, while the requirements for quartz cores are shockproof packaging and stable constant-temperature storage to suppress microcrack expansion. Stainless steel is primarily concerned with chloride isolation, anti-rust sealing, and regular passivation maintenance. In order to mitigate fluoroplastic ageing and coating damage, PFA-coated radiators necessitate storage environments that are anti-oxidation, low-temperature, and anti-scratch. During shutdown idle periods, standardised sealed storage and periodic maintenance can effectively prevent permanent performance degradation and structural damage of heating equipment, thereby reducing rework and replacement costs upon production restart..