Oil tank cleaning operations involve flammable and explosive oil-and-gas environments, posing extremely high safety risks. It is essential to strictly adhere to the following key precautions:

Preparation before homework

1. Qualifications and Plans: The operating unit must hold cleaning qualifications and prepare an HSE work plan and an emergency response plan. Construction may only commence after these documents have been reviewed and approved by the competent authority.

2. Environmental Monitoring: Before cleaning, use professional instruments to detect the concentration of oil and gas inside the tank. If the concentration exceeds 20% of the lower explosive limit, the area within a 35-meter radius shall be designated as an explosion hazard zone, and any hot work is strictly prohibited.

3. Ventilation and Air Exchange: Open all manholes and cleaning holes, and use explosion-proof axial fans for forced ventilation. At the same time, install exhaust fans at the top to remove smoke and dust, ensuring that the oxygen content meets the required standards.

4. Tool Selection: Use explosion-proof tools made of copper, wood, or other non-sparking materials. It is strictly prohibited to carry items such as iron objects and synthetic fiber ropes that can easily generate static electricity or sparks.

Personnel Protection Requirements

1. Personal Equipment: Operators must wear anti-static work服, gas masks, and safety shoes; they must also wear signal ropes and safety belts. A dedicated supervisor must be stationed outside the tank.

2. Shift System: Each individual entry into the tank should not exceed 20 minutes. During periods of high summer temperatures, shift work is required, and medical personnel must be on-site to provide supervision.

3. Static discharge: Before entering the tank, touch the static discharge device and avoid carrying items such as mobile phones and lighters.

Work Process Control

1. Hot Work Management: If hot work is required, a hot work permit must be obtained. All dead-end oil deposits inside the tank must be removed, and only after the concentration of flammable gases has been confirmed to meet the required standards can construction proceed.

2. Lighting Safety: Use 12V explosion-proof lighting fixtures, and the power cables must be routed overhead. It is strictly prohibited to connect them directly to components inside the tank.

3. Wastewater Disposal: Wastewater from cleaning operations must be discharged into an oil-water separation tank. It is strictly prohibited to dump it indiscriminately to prevent environmental pollution.

Emergency and Finishing Up

1. Emergency Preparedness: Equip the site with fire-fighting equipment and first-aid supplies, and develop emergency response plans for incidents such as fires and poisoning.

2. Acceptance and Restoration: After cleaning, both parties shall conduct acceptance inspection to confirm that there is no rust, impurities, or moisture present. Then, seal the manhole and restore the pipeline connections.

3. Record Archiving: Fully document the cleaning process, inspection data, and acceptance results, and retain them for future reference.