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V. Ventilation 
This template has been developed to further standardize the standard procedures for restricted space operations. Worth a reference! .
I. Qualification certificate
1. Safety construction operation permit: Before the construction operation, the construction unit must carry out three levels of safety training (contractor internal, Party A plant level, Party A workshop level construction training) and pass the examination. The training results should be registered on the safety construction operation permit. And carried by the construction staff.
2. Guardianship certificate: The construction site must be equipped with guardians of both Party A and Party B. The guardian must be a male, and the guardian must obtain the qualification of the operation guardian and hold the certificate;
Second, equipment and emergency
1, work tools
Equipment and facilities used in confined space operations in explosion-proof areas in production areas shall be explosion-proof machine tools, which shall be inspected before entering the site, and may be used after pasting the inspection qualified labels.
2, emergency
When working in confined spaces, it is necessary to formulate necessary emergency rescue measures, configure fire-fighting, gas-proof equipment, gas masks, emergency medicines according to requirements, set up guardians externally, and adopt effective contact methods to keep abreast of internal conditions. For more than 5 days of Level 3 and 4 risk-constrained space operations, an emergency drill is required before starting work.
Third, the work permit
1. The operation permit carries out the relevant requirements of the petrochemical company's Operational Risk Assessment License Management Procedure. The conventional restricted space and dirty restricted space operations are carried out according to the level 3 risk operation, and the inert gas limited space and the unconventional operation are in accordance with the level 4 risk. The work is carried out.
2, 4 levels of restricted space operations must prepare an operation plan.
Fourth, personal protection
1. Persons entering restricted spaces are strictly prohibited from wearing non-static work clothes and work shoes. The entering personnel should wear protective gloves, goggles, gas masks (or long-tube respirators, external cleaning air sources) according to the actual working environment. When the confined space gas detection fails, the personnel must use the external cleaning air source.
2. Two or more long-tube respirators or positive-pressure air respirators are provided outside the operation point. One or more sets of safety ropes shall be trained by the provider to the personnel of Party B before the construction to ensure the correct use of Party B.
In order to ensure the air circulation and personnel breathing in the confined space, it can be naturally ventilated; when special circumstances such as oxygen consumption or cleaning of toxic and hazardous substances in a confined space, forced ventilation should be adopted; the oxygen concentration in the confined space is controlled at 19.5. Between % (V / V) and 23.5% (V / V). The selection of fan power can be performed in accordance with Appendix A.
Sixth, gas detection
Confined space operation monitors must carry portable 4-in-1 detectors to continuously monitor the working environment. The limited space where benzene series and prominent organic volatile gases are harmful should also be continuously monitored by VOC detector. The middle and lower parts are tested separately, and any gas purge should be stopped during sampling. The frequency of data recording in the work ticket is still filled in as required.
Seven, lighting
Confined space operations must ensure adequate lighting, electrical equipment used must comply with the overall explosion-proof requirements, lighting should use explosion-proof (emergency) lighting.
Eight, civilized construction
1, pre-work check
Into the confined space, it is necessary to determine that the energy isolation is in place, and the confined space is cleaned and cleaned up to meet the requirements.
2, identification and alert
A warning zone shall be set up at the construction site, and warning signs and work notification signs shall be hoisted at the entrance of the confined space. When the operation is stopped, the entrance and exit of the personnel must be installed with the "No Entry" sign.
3. Registration of personnel materials
The tools and materials that carry the work in the restricted space should be registered, and should be counted after the work is finished to prevent leaving it at the job site. Operators entering restricted spaces should register for entry and exit and inventory.
4, working time
The restricted space operation should be avoided as much as possible during the high temperature period at noon. The working environment is below 38 °C, the operator should rotate at least 60 minutes, and the rest should be no less than 15 minutes. If the working environment exceeds 38 °C (including 38 °C), special items should be carried out. Risk assessment to shorten the time per job.
5, access channel
Confined space operations must establish access to and from personnel access and emergency rescue.
6, contact, communication, fall prevention
The guardian and the operator should clearly communicate with the walkie-talkie, lighting flashing, etc. and always maintain effective communication. Safety measures to prevent falling or slipping should be established in confined spaces, and safety equipment such as fall arresters should be used.
Confined space working ventilation volume and fan selection
Sufficient ventilation must be maintained in confined spaces for forced ventilation, with oxygen concentrations controlled between 19.5% (V/V) and 23.5% (V/V). An explosion-proof ventilator must be used. The ventilator must not be installed overhead on the outside of the vent. The ventilator must be connected to the vent. The ventilation type adopts the upper draw-down type. For the trenches, pools, tanks and other places with only the upper vents, the air duct must be provided with forced air supply from the outside (the air line of the device is strictly prohibited), and the air duct must extend to the bottom of the confined space. . The selection of fan power can be performed by referring to the following.
1, the volume below 1000 square, select the ventilation of not less than 2000 squares;
2, the volume of 1000 square to 5000 squares, select the ventilation of not less than 5000 squares;
3, the volume of more than 5000 squares, select the ventilation of not less than 9000 squares;
4, the volume of 50,000 square meters and above, as well as the complex internal structure of the confined space, blocking the flow of ventilation, there is a ventilated dead angle, special risk assessment shall be carried out, and the ventilation plan shall be prepared;
5, the fan must use explosion-proof fan and explosion-proof wiring.
6. For restricted spaces with only one port, priority should be given to emergency access.
Limits of toxic and harmful factors in confined space painting operations
Entering confined space painting operations, the toxic and hazardous substances in the confined space shall not exceed the maximum allowable concentration in GBZ2-2007 Occupational Exposure Limits for Harmful Factors in the Workplace. The combustible gas or vapor concentration is lower than 10% of the lower explosion limit of the air mixture; the CO concentration is lower than 30 mg/m3; the hydrogen sulfide concentration is less than the limited space of 10 mg/m3; the oxygen concentration is 19.5% (V/V) and 23.5%. Between (V/V)).
If the above conditions are not met and work must be carried out, the second phase of risk assessment should be carried out jointly by the operating unit and the unit in which the space is confined. Special protective measures should be taken to use the externally supplied clean air source and organize a simulation exercise before the operation. Only after confirming that it is safe and reliable can you perform the work.