Dangerous factors and Preventive Countermeasures i

Dangerous factors and Preventive Countermeasures in equipment maintenance (petrochemical enterprises)

compared with other enterprises, equipment maintenance in petrochemical enterprises has the characteristics of frequent, complex, highly technical and dangerous rush repairs. Petrochemical enterprises have relatively centralized equipment layout, relatively narrow maintenance sites, often crisscross and three-dimensional intersection, inside and outside the equipment, high altitude and underground at the same time. During maintenance operations, hot work, high-altitude operation Operations in tanks, lifting operations, electrical operations, disassembly and assembly operations, etc. are carried out at the same time. If the organization is not tight, the plan is not comprehensive, and negligence, accidents are prone to occur. According to statistics, among the explosion, poisoning, suffocation, falling, electric shock and other casualty accidents in petrochemical enterprises across the country, the casualty accidents during maintenance account for more than 66%. Therefore, it is particularly important to take effective safety countermeasures in the process of equipment maintenance.

1 The main manifestations of the danger of hot work

(1) the system safety measures are not in place. For example, the longitudinal samples are not treated cleanly, and the shape of inclusions is mainly studied; Identify the type of inclusions, there are dead corners in the container, the blind plate is inserted unreasonably, the connected material pipelines are not separated, the valve leaks, etc., which are prone to fire and explosion accidents during hot work.

(2) flammable and explosive media are adsorbed on the scale on the inner wall surface of equipment and pipelines or in the thermal insulation materials on the outer surface. If they are not treated cleanly, they will be released during hot work, Prone to fire and explosion accidents.

(3) there are inflammables and explosives around and below the production hot work point of petrochemical enterprises. If they are not cleaned up, they are prone to fire and explosion accidents.

(4) in terms of management, they do not handle the hot work permit as required and do not implement the safety measures specified in the action fire permit, which is easy to cause fire and explosion accidents.

2 The main manifestations of the danger of operation in the equipment

1 Do a good job in the preparation of maintenance

(1) organizational preparation. First, establish and improve the organizational leadership of equipment maintenance and the safety maintenance system at all levels; Secondly, the maintenance organization should be reasonable, and the person in charge of maintenance, the person in charge of safety and the construction personnel should be clear about the task and know well. (2) measures should be prepared. The maintenance items and construction contents should be approved; Formulation of construction scheme, shutdown and start-up scheme and schedule; For major overhaul projects and major and complex hoisting projects, hoisting plans and safety technical measures must be formulated. The construction department and the implementation of construction safety measures must clarify the safety discipline for entering the construction site, and assign personnel to be responsible for the publicity, inspection and supervision of the position that should be judged to be able to fly down first according to the site safety regulations.

(3) material preparation. According to the overhaul projects, contents and requirements, Prepare the materials, accessories and equipment required for maintenance, and carry out the prior safety inspection of lifting equipment, welding equipment, electric tools, riggings and slings; Check the safety warning signs, no moving signs, no switching on signs, blind plates, and grounding wires to ensure that they are complete in variety, sufficient in quantity, qualified in quality, and used in place.

(4) personnel preparation. It is necessary to clarify the safety responsible person for maintenance, establish a safety leading group, and clarify the responsibilities of safety responsible persons at all levels and the procedures for mutual cooperation and liaison; Carry out comprehensive safety education for all personnel participating in the maintenance, explain the safety problems that should be paid attention to in each item and link of the maintenance safety construction scheme, and the person in charge of each maintenance should do "five Confessions" before construction, that is, to explain the construction tasks, safety construction measures, safety construction methods, safety precautions, and compliance with relevant regulations, Safety education focusing on the safety technology and overhaul regulations of special types of work should be carried out for personnel, so that they can adapt to and be competent for overhaul work.

2 Strictly implement the maintenance measures

(1) eliminate the dangerous factors of the equipment. The equipment in operation must be subject to a series of measures such as shutdown, pressure relief, discharge, cooling, plugging blind plate extraction, replacement, purging, cleaning, safety analysis, power cut-off and so on, so that it can be maintained in a safe state.

(2) strictly apply for the safety construction maintenance certificate. The maintenance assignment must be handled for any maintenance project, It is a certificate for assigning maintenance tasks, clarifying maintenance contents and safety measures, recording maintenance conditions and inspection and acceptance, and a measure to ensure maintenance quality and safety. After the equipment is eliminated from danger, the person who hands over the equipment signs on the task book, indicating that the safety measures for equipment maintenance have been implemented, The construction personnel can carry out maintenance and construction.

for various operations, the corresponding safety work permit shall be handled in strict accordance with the regulations. ① all welding and cutting operations in the no fire area and the temporary operations that may produce flames, sparks and red hot surfaces in flammable and explosive places using blowtorches, electric drills, grinding wheels, etc. need to apply for a "hot work safety permit", and the hot work can be started within the specified time after being reviewed, approved and signed; ② All operations carried out in various towers, balls, kettles, tanks, tanks, furnaces, boilers, pipelines, containers, basements, pits, sewers or other closed places in the petrochemical production area shall be subject to the "permit to enter equipment containers". All power supplies connected to the outside world on the equipment shall be effectively cut off. The safe isolation of pipelines can be achieved by inserting blind plates or removing a section of pipelines, and water seals, water seals, and The valve replaces the blind plate or removes the pipeline. The blind plate cannot be replaced by iron sheet or asbestos pad, and the thickness of the steel plate cannot be less than the wall thickness of the pipeline. Measures such as removing the power fuse or locking the power switch can be taken to effectively cut off the power supply, and warning signs should be hung. Isolation gas masks should be worn in anoxic and toxic environments. Explosion proof low-voltage lamps and tools that do not produce sparks should be used in flammable and explosive environments, It is not allowed to wear chemical fiber fabrics. The lighting voltage in the equipment should be less than or equal to 36V, and the operation in wet containers and narrow containers should be less than or equal to 12V; ③ All work at heights 2M and above the falling height datum and with falling danger shall be handled with a "high place safety work permit". The high place operation approver shall go to the high place operation site to check and confirm the safety measures before approving the high place operation; Personnel working at heights must receive safety education, be familiar with the site environment and construction safety requirements, and are not allowed to work at heights for personnel with occupational contraindications, old age, weakness, fatigue, poor vision and drinking; ④ The establishment of temporary power supply must comply with the safety regulations. In view of this problem, it is not allowed to connect or set up arbitrarily. The open-air switching equipment should have rain proof and moisture-proof facilities. The electrician operation should strictly implement the work ticket system. Other operations such as lifting operations, earth moving operations, etc. should also apply for corresponding work tickets, After approval, it can be carried out.

(3) fire fighting measures are in place. During the maintenance period, it is necessary to ensure that the fire fighting in the plant area is expected to become a new consumption hot spot and a new economic growth point. The roads are unobstructed, the fire water pressure is sufficient, and all kinds of fire fighting equipment are complete and easy to use. In principle, when stopping the fire water, it is forbidden to carry out hot work within the scope of stopping the water. If it is necessary to carry out local hot work, there must be fire prevention and fire extinguishing emergency measures.

3 Supervise and inspect the safety management of the operation site

the safety management personnel at all levels and the project leaders should work in pieces, and carry out patrol inspection and supervision within their respective scope of responsibility. Focus on the inspection of the implementation of rules and regulations, the implementation of various tickets, the implementation of organization and discipline, the standby and integrity of safety facilities, the installation and use of temporary electrical lines, the allocation and use of tools and instruments for maintenance, etc, Strengthen the investigation and punishment of violations in the above aspects. Strengthen the safety binding force, set up a "violation exposure platform" in the maintenance, and timely make public exposure to units and individuals who do not implement safety regulations, illegal commands, and illegal operations in the maintenance. During the maintenance, the site should be cleaned frequently, materials and tools should be stacked correctly, safety signs or protective railings should be set in dangerous areas, and red light signals should be set at night.

4 Check the acceptance of maintenance

after the maintenance, the maintenance workers should clean the site and remove all oil stains, garbage and corner waste; All safety facilities such as railings, safety covers, equipment covers, grounding and zero connection shall be restored to their original state. Before the handover, check whether there are missing maintenance items, whether all blind plates to be pumped have been pumped (implemented one by one, and cannot be omitted), whether the safety devices are sensitive, etc. pressure tests, leakage tests and air tightness tests must be carried out for pressure vessels, storage tanks and other equipment as required, Finally, verify the equipment or system through commissioning. (Gao Yueli)

(1) toxic and harmful gases may cause poisoning if they are not cleaned, replaced and analyzed to be qualified.

(2) the oxygen content in the container does not meet the requirements, which may cause suffocation.

(3) long operation time and poor ventilation of the container, There is a risk of suffocation.

(4) the power supply used for lighting and electric tools in the container is not a safe voltage or the power line is damaged, and the tools and equipment leak electricity, which may cause electric shock accidents.

(5) entering the toxic area without anti-virus equipment, entering the equipment for operation with defects in anti-virus equipment, insufficient oxygen source, reagent failure, etc., may cause poisoning accidents.

(6) entering the high-depth container for operation, Incomplete safety measures may cause object strike accidents.

3 The main manifestations of the danger of working at heights are

(1) the erection of scaffolding is not standardized and has poor stability, resulting in falling accidents.

(2) when the surrounding environment changes and toxic gases are suddenly emitted, it is easy to cause poisoning and falling accidents.

(3) the measures are not implemented (without a work permit, safety belt and helmet), resulting in falling accidents and object strike accidents.

(4) fences during maintenance After the floor is removed, it falls without taking corresponding measures.

in addition, during the maintenance process, personnel also have the risk of being burned and burned; Or collision, fall, fall and injury in a narrow place; Or being caught in running machinery and equipment, breaking limbs, and accidents caused by unchecked hoisting machinery, hoists, and manual grinding wheels used in construction should also be paid great attention to