1. Work Safety Management Hidden Danger Inspection Checklist
1. Enterprises should establish management systems for special operations such as hot work and confined space entry. Standardize the safety conditions and approval procedures for special operations such as hot work, confined space entry, and blind flange removal.
2. Before special operations, work permits should be processed according to system requirements. Inspect the enterprise's hot work, confined space, and other special operation sites or work permits, and verify the permit processing status (work permit approval and filling should be standardized, including permit validity, gas analysis, hazard analysis, control measures formulation, multi-level approval, acceptance confirmation, and related permit processing).
3. Hot work on production equipment in facilities or pipelines containing or having contained oxidizing or flammable and explosive hazardous chemicals, as well as fire and explosion hazard areas specified in GB 30871, must be completely disconnected or isolated from the production system. Water seals or simply closing valves should not replace blind flanges as isolation measures.
4. Confined space work sites should be equipped with portable gas detection alarms to continuously monitor combustible gases, toxic gases, and oxygen concentration inside the confined space, with records taken every 2 hours.
5. During holidays, public holidays, nighttime, or other special circumstances, hot work should be managed with upgraded controls.
6. For special-grade hot work, the entire operation process should be recorded on video, and the recording equipment used on site must be explosion-proof.
7. Special operation site supervisors must undergo relevant training and pass assessments, holding valid training certificates. Interviewed supervisors should be familiar with the process, equipment, and material status within the work scope and possess emergency rescue and handling capabilities.
8. During abnormal condition handling operations involving opening pipelines or equipment, pressure relief and purging should be performed before and after the disassembled parts, and effective physical isolation from the operating system must be ensured. Closing valves must not replace the installation of blind flanges.
9. During abnormal condition handling operations, pressurized sealing and pressurized hole opening should be avoided unless necessary. If required during emergency handling, a feasibility assessment should be conducted, the site environment and equipment status surveyed, and a special operation plan formulated.
10. Contractors should receive factory entry training, and the grassroots unit at the work site should provide on-site safety briefings before work; supervision and inspection of contractor work sites should be implemented.
11. Enterprises with major hazard sources should establish and use special operation approval and management systems, and personnel positioning systems (including personnel gathering risk monitoring and early warning functions).
12. For key maintenance projects, maintenance plans should be prepared, including work safety analysis, safety risk control measures, emergency response measures, and safety acceptance standards; safety conditions should be confirmed before equipment handover for maintenance and before reuse after maintenance.
13. Relevant enterprise systems should clearly define the scope of hazardous operations such as tank water cutting, liquefied hydrocarbon filling, and maintenance of equipment with high safety risks.
14. Enterprises should establish operating procedures for hazardous operations and strictly follow these procedures during work (enterprises are not required to have hazardous operations other than special operations; this depends on the enterprise's facilities).
15. During water cutting, dehydration, and other high-risk liquid discharge operations, operators must not leave the site.
2. Storage, Transportation Safety and Emergency Management Hidden Danger Inspection Checklist
1. Hazardous chemical warehouses should be formally designed, with fire resistance levels and fire compartments meeting relevant standards.
2. Warehouse design should be based on normative standards, specifying stored materials and maximum quantities.
3. Hazardous chemicals should be stored separately by zone and category according to national standards; overstocking or storing excessive varieties is prohibited, and incompatible substances must not be mixed.
4. Firefighting facilities should meet requirements and must not be invalid or out of service.
5. Enterprises should identify possible emergencies and abnormal situations based on risk assessments, combine operational experience and accident lessons, and prepare targeted comprehensive emergency plans, special emergency plans, and on-site response plans as required.
6. Based on emergency plans, emergency response cards should be prepared according to workplace and position characteristics; evaluations should be conducted after drills to analyze problems and propose revisions to emergency plans.
7. Employees should have necessary emergency knowledge, master risk prevention skills, and accident emergency measures.
8. High-risk industries should organize at least one evacuation drill every six months; employees should be familiar with escape routes, safety exits, and emergency response measures.
9. Position employees should be proficient in wearing air respirators, following correct procedures.
10. Air respirator pressure should meet the requirements of the user manual, and masks, harnesses, etc., should be intact.
3. "Three Simultaneities" and Trial Production Management Hidden Danger Inspection Checklist
1. Construction projects must undergo safety condition review and safety facility design review; construction must not start without these reviews.
2. The main safety technical measures in safety evaluation reports, safety facility design chapters, or safety design diagnosis reports should be implemented during project construction.
3. If the design of safety facilities changes and may reduce safety performance or requires redesign of safety facilities, a review of the safety facility design changes should be conducted.
4. Before trial production, the construction unit shall organize experts to demonstrate the trial production plan, confirm the trial production conditions, and provide technical guidance during the trial production process. The trial production plan shall be approved by the main person in charge of the construction unit.
5. Before trial production, the construction unit shall carry out the "Three Checks and Four Determinations" by specialty (check for design omissions, check engineering quality and hidden dangers, check unfinished work volume, assign rectification tasks, personnel, time, and measures), form a list of identified problems, and complete the rectification.
6. For major hazard sources involved, the construction unit shall complete the data access for major hazard source safety monitoring and control as required.
IV. General Safety Management Requirements Hidden Danger Inspection Checklist
1. Enterprises shall establish and improve the safety production responsibility system for all employees, clearly defining the safety production responsibilities and assessment standards of management departments at all levels and grassroots units.
2. The safety production responsibilities and assessment standards of the main responsible persons, management personnel at all levels, frontline employees (including labor dispatch personnel, interns, etc.), and all other positions shall be clearly defined.
3. Enterprises shall legally set up safety production management organizations or assign full-time safety production management personnel; the main responsible persons and safety production management personnel of the enterprise shall be assessed and qualified by the competent department responsible for safety production supervision and management in terms of safety production knowledge and management ability.
4. The main responsible persons and safety production management personnel of the enterprise shall receive annual retraining.
5. The technical person in charge shall organize the review of relevant qualifications and safety management of external construction units and personnel involved with major hazard sources, and review change management related to major hazard sources.
6. The technical person in charge shall organize at least one targeted safety risk and hazard inspection of major hazard sources each quarter; the operation person in charge shall organize at least one safety risk and hazard inspection of major hazard sources each week.
7. Relying on the hazardous chemical safety production risk monitoring and early warning system or the dual prevention system platform, enter the major hazard source responsibility person (duty record) online.
8. Establish a safety risk assessment and commitment announcement system, where the chairman or general manager and other main responsible persons make daily safety commitments and announce them to the public.
9. Enterprises shall announce the safety risk control status of major hazard sources in the safety risk commitment announcement. The commitment content should include the implementation of major hazard source safety responsibility and special operations. Randomly check a recent hot work or confined space special operation to see if it was announced in the commitment announcement on the day of the operation.
10. Enterprises shall establish and implement a safety production expense management system; enterprises shall establish a ledger for the extraction and use of safety production expenses, detailing the usage of safety production funds.
11. The main responsible persons of production and operation units in high-risk industries shall lead teams to conduct at least one inspection per month on the investigation and rectification of major accident hazards in their units.
12. Relevant enterprise systems shall specify requirements for densely populated areas within the plant and situations with potentially significant risks; the following situations shall not exist on-site.
(1) During the start-up and feeding period of the unit after trial production or maintenance, no construction work shall be carried out in the area;
(2) In production workshops (areas) involving key regulated chemical processes such as nitration, chlorination, fluorination, diazotization, peroxidation, and other reaction processes with hazard level 2 or above, the number of on-site operators at the same time shall be controlled to less than 3;
(3) Under normal operation of production units, no more than 9 people shall be present on the same work platform or in the same confined space for maintenance of a single (set) equipment unit;
(4) When the unit experiences leaks or other abnormal conditions, strictly control the number of personnel on site.
13. Enterprises shall establish and improve authorization mechanisms for emergency shutdown and personnel evacuation by post personnel.
V. Equipment Safety Management Hazard Inspection Checklist
(1) Establishment and Implementation of Equipment Management System
1. Enterprises shall conduct regular patrol inspections of equipment and establish records of regular equipment inspections.
2. Enterprises shall strictly manage equipment changes:
(1) Changes shall follow the procedures of application, approval, implementation, and acceptance;
(2) A comprehensive analysis of potential safety risks after changes shall be conducted, and safety risk control measures shall be formulated and implemented;
(3) After changes, enterprises shall update relevant procedures, drawings, and other safety production information;
(4) After changes, relevant personnel shall be trained to master the change content, updates to safety production information, potential safety risks after changes, and the control measures taken.
3. Enterprises shall not use equipment that is nationally banned or eliminated and endangers production safety.
(2) Safety Risk Assessment of Aging Units and Preventive Maintenance and Testing of Equipment
1. For enterprises that have obtained hazardous chemical safety production permits and safe use permits, and involve major hazard sources, key regulated hazardous chemical processes, toxic gases, or explosives:
(1) Conduct rolling self-inspections of aging units;
(2) Check whether there are units with main reactors, pressure vessels, atmospheric tanks, cryogenic tanks, and GC1 level pressure pipelines that have reached the design service life or have been in operation for more than 20 years, and whether safety risk assessments of aging units have not been conducted.
2. Establish "one device, one policy"; assess whether the identified issues and hidden dangers of existing old devices have been rectified; for those not yet rectified, clarify rectification measures, deadlines, responsible persons, rectification funds, and control measures according to the "Five Fixes" requirements; check the implementation of control measures.
3. Equipment, facilities, pipelines, and fittings should be installed according to design requirements. It is strictly forbidden to add or remove equipment, pipelines, safety accessories, etc., without design approval or change procedures, or to arbitrarily change the model and material of equipment and pipelines.
4. Enterprises should strengthen corrosion management, identify inspection locations, and conduct regular testing. Check for issues such as pipeline wall thickness corrosion thinning that no longer meets design requirements; corrosive substance content in pipeline media exceeding normal range without enhanced corrosion detection, yet still in use.
5. At discharge points, sampling points, and other emission locations involving flammable, explosive, and toxic media equipment and pipelines, measures such as installing blind flanges, plugs, pipe caps, and double valves should be taken to reduce leakage possibilities.
6. Acid and alkali pipeline flanges lack splash prevention measures.
7. Permanent connection points on liquefied hydrocarbon pipelines used for purging and displacement should have double valves; a check valve, drain guide, and blind flange should be installed between the double valves. Double valves or a single valve with sealing facilities should be installed at liquefied hydrocarbon pipeline venting and draining points.
8. Liquefied hydrocarbon, liquid chlorine, and liquid ammonia pipelines must not use hose connections; combustible liquid pipelines must not use non-metallic hose connections.
9. Bolts for connections in pressurized parts should be complete and properly tightened.
10. Check whether there are serious deformations and cracks in pressure pipeline supports and hangers, and issues such as subsidence, tilting, and cracking of pressure vessel and storage tank supports or foundations on site.
11. Check whether there are serious rust and severe insulation layer damage on the outer surfaces of pressure vessels, pressure pipelines, and storage tanks on site.
12. Check whether there are leaks in equipment and pipelines (elbows, flanges, reducers, etc.) involving flammable, explosive, and highly toxic materials, and whether effective measures have not been taken while continuing operation.
13. Check whether temporary anti-leakage measures such as "clamps" have been used on pipelines involving flammable, explosive, and highly toxic materials.
14. For devices, equipment, and pipelines involving flammable, explosive, and highly toxic materials, equipment and facilities that repeatedly show abnormalities and are assessed as needing elimination are still in use.
(3) Management and operation status of rotating equipment
1. Enterprises should monitor operating parameters such as speed, vibration, displacement, temperature, and pressure of large units and key rotating equipment, and promptly assess equipment operating status.
2. Combustible gas compressors, liquefied hydrocarbon pumps, and combustible liquid pumps must not use belt drives.
3. Other transmission equipment in explosion hazard areas must use anti-static belts if belt drives are necessary.
4. Centrifugal combustible gas compressors and combustible liquid pumps should have check valves installed on their outlet pipelines.
5. Check whether there are abnormal vibrations in machines, pumps, or pipelines involving flammable, explosive, and highly toxic materials, and whether they continue to operate without cause analysis and corrective measures.
(4) Management of static equipment
1. Enterprises should set safety accessories such as tank breathing valves (hydraulic safety valves), flame arresters, foam generators, level gauges, and vent pipes according to standards.
2. Regularly inspect or test safety accessories and fill in inspection and maintenance records.
3. Flexible connections should be used for inlet and outlet pipelines of aboveground combustible liquid storage tanks.
4. On-site management of heating furnaces should meet the following: during combustion, interlocks for low or interrupted process medium flow, overpressure and underpressure of fuel gas pipelines, and induced draft fan shutdown interlocks should function normally; control and detection instruments on the furnace should be operational and fault-free; all oxygen analyzers should be regularly calibrated.
5. The fire-fighting steam system should be in standby status.
6. The fire safety distance between fuel gas separation tanks, fuel gas heaters, and the furnace body of open-flame heating furnaces should not be less than 6 meters.
7. Condensate from the separation tanks on heating furnace fuel gas pipelines must not be openly discharged.
8. Emergency shut-off valves should be installed where heat transfer oil pipelines enter production facilities.
9. Heat transfer oil furnace systems should have safety relief devices installed. Fuel gas pipelines for heat transfer oil furnaces should have low-pressure alarms and low-low pressure interlock cut-off systems, and flame arresters should be installed between the fuel gas regulating valve and the heat transfer oil furnace.
10. Materials with chemical burn hazards should not use fragile materials such as glass for pipelines, fittings, valves, flow meters, pressure gauges, etc.
11. Design documents for device pressure vessels should be complete, including calculation books, drawings, manufacturing and inspection technical requirements, etc. For old pressure vessels that have been renovated or undergone major repairs after August 31, 2009, Class III pressure vessels should have a risk assessment report (design stage).
12. The user unit of the pressure vessel shall manage the safety of the pressure vessel in accordance with the relevant requirements of the "Special Equipment Use Management Rules", establish a safety management organization, apply to the department responsible for special equipment use registration at the location for a special equipment use registration certificate as required, and conduct regular inspections. For devices, equipment, and pipelines involving flammable, explosive, or highly toxic materials, pressure-bearing special equipment and pipelines that exceed the statutory inspection period shall not continue to be used.
(5) Management of safety accessories
1. Safety accessories such as safety valves and pressure gauges should be regularly inspected and used within the valid period.
2. Safety accessories such as safety valves and rupture discs should be normally put into use. The inlet and outlet shut-off valves of safety valves in use should be fully open and sealed with lead or locked.
1. Firefighting systems should be installed, with normal water discharge at the endpoints; the water supply pressure of fire hydrants in the tank area should be normal and meet firefighting requirements. Fire pumps and pressure stabilizing pumps should each have standby pumps.
2. Firefighting equipment should meet the following requirements: firefighting cabinets should be fully equipped with intact accessories; there should be dedicated personnel responsible for regularly inspecting firefighting equipment, regularly replacing agents, with replacement records and valid tags.
3. Fixed or mobile firefighting cooling water systems should be installed for aboveground vertical storage tanks containing flammable liquids.
4. Storage tanks with tank walls higher than 17m, tanks with a volume equal to or greater than 10,000m³, and low-pressure tanks with a volume equal to or greater than 2,000m³ should be equipped with fixed firefighting cooling water systems.
5. Control valves of fixed firefighting cooling water pipelines for full-pressure and semi-refrigerated liquefied hydrocarbon storage tanks should be located outside the fire dike of the tank area, and the distance to the protected tank wall should not be less than 15m.
6. For fixed firefighting cooling water systems of vertical storage tanks containing flammable liquids (water spray or water mist systems), control valves should be located outside the fire dike and not less than 15m from the protected tank wall.
VI. Instrument Safety Management Hazard Inspection Checklist
(1) Instrument safety management
1. Enterprises should establish and improve various ledgers for instrument inspection, maintenance, use, calibration, and instrument patrol inspection records.
2. Enterprises should establish a system for professional countersignature and technical responsible person approval for shutdowns and changes of safety interlock protection systems.
3. Management of interlock protection systems should meet the following:
(1) Complete technical documents such as interlock logic diagrams, regular maintenance and calibration records, and temporary shutdown records;
(2) Regular debugging of process and equipment interlock loops;
(3) Changes to the interlock protection system (set values, interlock programs, interlock methods, cancellations) should undergo approval procedures: (check whether the enterprise has interlocks with conditions like 2 out of 2 that are difficult to trigger, verify if they are later changes, and if so, whether the changes are reasonable);
(4) Removal and restoration of interlocks should be handled with work permits, countersigned by departments and approved by leaders: (interlocks should not be removed for long periods);
(5) Removal of interlock protection systems should have preventive measures and rectification plans.
(2) Control and instrument system setup
1. For main reaction equipment, emergency shut-off valves should be installed on raw material and utility pipelines entering the reaction vessel according to design and P&ID drawings (as-built drawings); safety interlock systems and automatic control systems for material and utility flow, temperature, and pressure regulation should be installed.
2. For main reaction equipment, sufficient numbers of remote transmission and local display monitoring and measuring devices for pressure, temperature, flow, etc., should be installed according to design and P&ID drawings (as-built drawings).
3. The explosion-proof level of instruments and corresponding facilities in explosive hazardous areas should meet the area's explosion-proof requirements.
4. Safety monitoring equipment in major hazard source tank areas for hazardous chemicals should meet requirements:
(1) The number and location of cameras should achieve full coverage based on the actual situation of the tank area site;
(2) The installation height of cameras should ensure effective monitoring of the tank tops;
(3) Explosion-proof cameras or explosion-proof measures should be used where explosion-proof requirements exist.
5. During emergency handling, interlocks shall not be removed or bypassed to forcibly maintain equipment or device operation without evaluation and permission.
After device interlock is triggered, the cause should be promptly identified, and interlock trigger conditions eliminated one by one; forced reset is strictly prohibited.
(3) Gas detection and alarm management
1. The setup of combustible gas and toxic gas detectors and alarm values should meet the requirements of GB/T 50493.
2. Install toxic, harmful, and combustible gas detection and alarm systems according to design and standard requirements: combustible and toxic gas detectors and alarms should be installed at pump seals, sampling ports, vent and drainage outlets, frequently disassembled flanges, and frequently operated valves.
3. Set alarm values correctly.
4. The combustible and toxic gas detection and alarm system should be independent of the basic process control system.
(1) Combustible and toxic gas detection alarm signals should be sent to control rooms or field operation rooms where operators are regularly stationed for alarm notification;
(2) Alarm and response records should be kept, and the causes of alarms should be analyzed.
VII. Electrical Safety Hazard Inspection Checklist
(4) Power Supply and Distribution System Setup and Electrical Equipment Facilities
1. The enterprise's power supply should meet the power supply requirements of different load levels:
(1) Level 1 loads should be powered by dual power sources; when one power source fails, the other should not be damaged simultaneously;
(2) For particularly important loads within Level 1, an emergency power supply should be additionally installed, and it is strictly forbidden to connect other loads to the emergency power supply system; the switching time of the equipment's power supply should meet the equipment's allowable power interruption requirements;
(3) The power supply system for Level 2 loads should preferably be supplied by two circuits. When the load is small or regional power supply conditions are difficult, Level 2 loads can be supplied by dedicated overhead lines of 6kV or above.
2. Electrical equipment in explosion hazard areas should comply with GB 50058 requirements (mandatory checks for locations involving hydrogen, ethylene, carbon disulfide, ethyl nitrate, water gas; do not overlook dust explosion sites).
3. The safety performance of electrical equipment should meet the following requirements:
(1) The metal casing of the equipment should have protective grounding to prevent leakage;
(2) Grounding wires must not be overlapped or connected in series; wiring should be standardized and contacts reliable;
(3) Exposed wiring should be laid along pipelines or equipment casings; concealed wiring should have grounding marks outside the wiring points; 4. Grounding wire connections should not be painted or insulated with pads.
(5) Lightning Protection and Anti-Static Facilities
1. Steel tanks for combustible gases, liquefied hydrocarbons, and combustible liquids must have lightning protection grounding. For Class A and Class B combustible liquid fixed aboveground tanks, when the roof thickness is less than 4mm, lightning rods and wires should be installed, and their protection range should cover the entire tank.
2. Class C liquid storage tanks may not require lightning rods and wires but must have induced lightning protection grounding.
3. Floating roof tanks (including internal floating roof tanks) may not require lightning rods and wires but should electrically connect the floating roof and tank body with two soft copper wires with a cross-sectional area of no less than 25mm².
4. Pressure storage tanks do not require lightning rods and wires but should be grounded.
5. Tank trucks and loading/unloading sites for flammable and explosive hazardous chemicals should have dedicated anti-static grounding wires.
6. Pipelines for combustible gases, liquefied hydrocarbons, combustible liquids, and combustible solids should have static grounding facilities at the following locations: entry and exit of device areas or facilities; boundaries of explosion hazard areas; pipeline pumps and pump inlet permanent filters, buffers, etc.
7. On the sampling port (oil gauging port) platform on the tank top, at 1.5 meters on both sides, a set of human static elimination facilities should be installed. These facilities should be electrically connected and grounded with the tank body. Sampling ropes, measuring rods, and other tools should be connected to these facilities.
8. Cable trenches inside the facility should have measures to prevent accumulation of combustible gases or sewage containing combustible liquids from entering the trench. Wall openings connecting cable trenches to substations or control rooms should be filled and sealed.
9. Temporary overhead power lines should use insulated copper core wires and be installed on dedicated poles or brackets. The maximum sag distance from the ground should not be less than 2.5m at work sites and not less than 5m when crossing motor vehicle lanes.
10. Cable routing paths should have conspicuous warning signs.
11. Cables laid openly along the ground should be laid along the base of building walls. When crossing roads or other areas prone to mechanical damage, protective measures against mechanical damage should be taken.
12. There should be no issues where temporary electrical work permits have expired but have not been removed on site.
VIII. Process Safety Hazard Inspection Checklist
(1) Process Analysis and Evaluation
1. Enterprises should conduct a safety risk identification analysis using the HAZOP method every 3 years for production and storage units involving "two key points and one major" and prepare HAZOP analysis reports. (Randomly check the division of HAZOP report nodes for units, whether there are missing nodes, and how the main nodes are analyzed: guide words, deviations, causes, and whether the measures taken are targeted.) 2. Recommendations proposed in the HAZOP analysis report should be implemented; enterprises should provide sufficient reasons for any unadopted measures.
2. Production enterprises shall not use processes listed in the catalog of outdated and eliminated technologies.
(2) Operating Procedures and Process Cards
The content of the operating procedures should include:
1. The production process flow, process principles, and normal control range of process parameters for the position (including design values, normal control ranges, alarm values, and interlock values), and handling of abnormal conditions (consequences and handling steps).
2. Operating steps and safety requirements for normal startup, normal operation, temporary operation, emergency operation, normal shutdown, and emergency shutdown of the unit.
3. Hazard information of hazardous chemicals involved in the position, emergency handling principles, and personal safety protection and occupational health precautions during operation.
4. Enterprises should regularly conduct training and assessment on operating procedures for position personnel, verifying the consistency between assessment content and the trained operating procedures.
5. Operators should master the control range of main process control indicators.
(3) Safety Control of Process Technology and Process Units
1. Safety control of hazardous chemical processes should be set according to the safety control requirements for key regulated hazardous chemical processes, key monitoring parameters, and recommended control schemes, combined with HAZOP analysis results. (According to the National Safety Supervision Administration documents, verify the DCS and field settings based on the as-built P&ID drawings).
2. Units involving key regulated hazardous chemical processes should be equipped with automated control and emergency shutdown systems, which should be normally put into use.
3. Automated control and emergency shutdown systems of hazardous chemical process units should be normally put into use.
4. For non-key regulated chemical processes, verify the on-site process control settings according to the P&ID drawings; the on-site process flow should conform to the design. During inspection, focus on: according to design and P&ID (as-built) flow requirements, equipped with metering tanks, buffer tanks, condensers, reflux tanks, receiving tanks, etc.
5. The settings of full valves, explosion-proof membranes, and explosion-proof doors should meet safety production requirements: for reaction equipment with sudden overpressure or instantaneous decomposition explosion hazards of dangerous materials, if safety valves cannot meet requirements, rupture discs or rupture discs with detonation tubes should be installed. The detonation tube outlet must face a safe direction without fire sources, and measures should be taken to prevent secondary explosions and fires if necessary; safety valves that may be blocked or corroded by materials should have rupture discs installed before the safety valve or adopt purging, heating, or insulation measures on other inlet and outlet pipelines.
6. The safety of the flare system should meet the following requirements:
(1) The capacity of the flare system should meet the safe discharge under unit accident conditions;
(2) The flare system should be equipped with sufficient pilot lights and have a reliable ignition system and fuel gas source;
(3) The flare system should be equipped with reliable flashback prevention facilities (water seal, molecular seal, etc.);
(4) The separation and condensate drainage of flare gas should meet requirements.
7. The setting of closed ground flares should meet the requirements of GB 50160.
(1) When using fixed roof tanks or low-pressure tanks to store flammable liquids, nitrogen or inert gas sealing should be used. For tanks with nitrogen protection facilities, the nitrogen sealing system should be intact and in use, and accident pressure relief equipment should be available;
(2) For batch operations with flammable and explosive hazards, nitrogen protection measures should be taken (combined with risk analysis);
(3) Fixed roof tanks for Class A B and Class B liquids should be equipped with flame arresters and breathing valves; for tanks sealed with nitrogen or other gases for Class A B and Class B liquids, accident pressure relief devices should also be installed;
(4) Tanks with nitrogen protection facilities should ensure the nitrogen sealing system is intact and in use.
(4) Process Operation Management
1. On-site gauge indication values, DCS control values, and operating procedure and process card control values should be consistent (randomly check main control parameters such as temperature, pressure, liquid level, at least 3 items).
2. Over-temperature, over-pressure, and over-liquid level operations are strictly prohibited during production; focus on:
(1) Verify whether the enterprise has overloaded operation by checking the process control values of main reaction equipment in the DCS;
(2) Verify whether over-temperature, over-pressure of the unit, and liquid level and temperature alarms and interlocks of tanks are in use, whether control indicators have been recently modified, whether change procedures are complete, and whether alarms have been handled;
3. Handling of abnormal conditions should comply with operating procedure requirements.
Production capacity, raw and auxiliary materials (including additives, additives, catalysts, etc.) and media (including changes in component ratios), process routes, flows and operating conditions, process operating procedures or methods, process control parameters, instrument control systems (including changes in safety alarm and interlock set values), and utilities such as water, electricity, steam, and air should be included in change management.
(5) On-site Process Safety
1. It is strictly forbidden for the floating roof of a normally operating internal floating roof tank to rest on the bottom.
2. The low liquid level alarm or interlock setting of the internal floating roof tank shall not be lower than the height of the floating roof support. Design and construction of tail gas systems:
(1) The exhaust gas modification system should undergo formal design (including exhaust gas treatment for fine chemicals);
(2) Different process exhaust gases or materials discharged into the same exhaust gas collection or treatment system should undergo risk analysis. When using multiple chemical storage tank exhaust gas interconnected recovery systems, safety demonstration approval is required. (Flame arresters that prevent explosion and detonation should be installed between each storage tank exhaust gas system, and issues related to explosion venting and flashback prevention in fine chemical exhaust gas treatment);
(3) It is strictly forbidden to mix gases that may chemically react and form explosive mixtures for discharge. Attention: materials that react with each other share a common waste gas main pipe, and the company has not conducted compatibility analysis on the waste gas flowing through the workshop exhaust gas vent pipes.
3. Extremely hazardous and highly hazardous media, Class A combustible gases, and liquefied hydrocarbons should adopt closed-loop sampling systems.
4. Sampling ports must not be installed on vibrating equipment or pipelines; otherwise, vibration reduction measures should be taken.
5. Condensate in combustible gas vent pipes should be recovered in a closed system and must not be discharged on the ground.
(6) Start-up and shutdown management
1. Safety management systems for start-up and shutdown should be established, clearly defining management content, responsibilities, and work procedures.
2. The company should organize professional technical personnel to develop start-up and shutdown plans based on hazard identification and risk assessment, and implement them after approval. Potential risks during recovery from temporary or emergency shutdowns should be analyzed with emphasis.
3. The company should prepare safety condition confirmation forms and organize professional technical personnel to confirm each item according to the forms to ensure effective implementation of safety measures.
4. The company should conduct key inspections on changed or repaired equipment, pipelines, instruments, and other auxiliary facilities to ensure safe operating conditions.
5. Before start-up and shutdown, the company should sign off on the following important steps:
(1) When performing washing, purging, or gas tightness tests, confirm that effective safety measures have been established;
(2) Before introducing steam, nitrogen, or flammable and explosive media, assign experienced professionals to confirm the process flow;
(3) When introducing materials, continuously monitor changes in material flow, temperature, pressure, liquid level, and other parameters to confirm correct process flow.
6. Strictly control the order and rate of material input and output according to the plan.
7. Assign dedicated personnel for continuous on-site patrol inspections to monitor leaks and other abnormal phenomena.
8. Strictly control the number of personnel on-site during start-up and shutdown, and promptly clear unrelated personnel from the site.
(7) Safety management of liquefied storage tank areas
1. Establish a "one tank area, one policy" approach to rectify hidden hazards.
2. For full-pressure storage tanks with material storage temperatures above 0°C and inlet/outlet ports at the bottom, if the volume is greater than 100, water injection facilities should be installed (except when the process medium has special requirements prohibiting water injection). For volumes less than or equal to 100, risk assessment should determine the need for water injection facilities. Water injection facilities should have measures to prevent liquefied hydrocarbons from entering the upstream water injection system.
3. Liquefied hydrocarbon storage tanks requiring water cutting should use a closed water cutting system composed of an automatic water cutter and sewage collection tank. Sewage discharged from the automatic water cutter should pass through the sewage collection tank, undergo flash evaporation and hydrocarbon separation before being discharged into the plant's sewage system. Flash steam should be discharged into a safety venting system. In regions where the average minimum temperature of the coldest month is below 0°C, the bottom water cutting line of liquefied hydrocarbon storage tanks should be equipped with heat tracing. Full-pressure and semi-refrigerated liquefied hydrocarbon storage tanks should have pressure relief regulating valves with overpressure safety discharge functions on the tank body or vapor phase communication balance line. These valves should have remote and local control functions.
4. Liquefied hydrocarbon pumps should have remote stop functions; pump outlets should be equipped with check valves and remote shut-off valves.
5. When liquefied hydrocarbons contain easily self-polymerizing unstable dienes and other materials, measures should be taken to prevent the formation of polymers. When storing easily oxidized and polymerized unstable liquefied hydrocarbons, nitrogen supplementation measures should be implemented.
6. Liquefied hydrocarbon loading should achieve quantitative loading functions. During loading, interlocks should stop loading in cases such as vehicle static grounding disconnection (as required by regulations) and detection/alarm of combustible toxic gas leaks.
7. Based on process safety needs and actual loading/unloading conditions, gas tightness detection procedures and additional gas tightness pressure test safety devices should be added for loading and unloading of liquefied toxic gases.
8. The Basic Process Control System (BPCS), Safety Instrumented System (SIS), combustible gas, and toxic gas detection systems (GDS) in liquefied hydrocarbon storage tank areas should be set up independently.
9. Pressure-type liquefied hydrocarbon storage tanks should be equipped with high liquid level alarms, low liquid level alarms, high-high liquid level alarms, and low-low liquid level alarms. The high-high liquid level alarm should interlock to close the tank feed emergency shut-off valve.
10. Loading and unloading facilities for liquefied hydrocarbons by rail and road should have easily operable emergency shut-off valves on loading/unloading pipelines at least 10 meters away from the loading/unloading vehicle position.
11. Pipelines transporting combustible gases, liquefied hydrocarbons, and flammable liquids should have emergency shut-off valves installed at the entrance and exit of the company fence.
12. Enterprises shall establish a reliability confirmation system for the interface connections of loading and unloading facilities when handling flammable, explosive, toxic, and hazardous chemicals: the connection ports of loading and unloading facilities must not have defects such as wear, deformation, local notches, or aging of rubber rings or gaskets.
