The anti-Qing movement began with the looting of the Eight-Nation Alliance.

Chapter 179 Discovered

Control valves cannot be used as material isolation devices on their own. If control valves must be used for isolation, specific operating procedures should be developed to ensure safe isolation.

For operations already covered by the first operating procedure and for new projects, no pipeline opening permit is required.

Article 2. The unit responsible for the work area shall conduct a risk analysis regarding the pipeline opening operation, work environment, etc., and provide safety briefings to the work units. The work units shall participate in the risk analysis and formulate corresponding control measures or plans based on the results. The safety work plan shall include the following main contents:

(a) The cleanup plan should specifically describe the valves to be closed, the venting points, and the locking points, and should provide a schematic diagram if necessary;

(ii) Safety measures, including cooling and nitrogen purging measures and personal protective equipment requirements during pipeline opening;

(iii) When necessary, the requirements and responsibilities of reserve personnel for emergency response, rescue, and monitoring;

(iv) When necessary, develop emergency response plans;

(v) Describe the area affected by the pipeline opening and control personnel access.

Article 3. Based on the properties, temperature, pressure of the medium in the pipeline and the diameter of the pipeline flange sealing surface, select appropriate materials, strength, diameter and blind flanges and gaskets that meet the design and manufacturing requirements. High-pressure blind flanges shall be subjected to ultrasonic testing before use.

Article 4 The selection of blind flanges shall comply with the requirements of "Steel Insert Plates, Gaskets and Figure-8 Blind Flanges for Pipelines" or "High-Pressure Blind Flanges for Valve Components". The materials selected shall be flat, smooth, and free of cracks and holes.

Article 5 The unit or grassroots unit where the work area is located shall draw a blind plate location map in advance, uniformly number the blind plates, and assign a dedicated person to uniformly direct the work.

Article 6. The work unit shall carry out blind flange removal and installation work according to the diagram, and mark each blind flange with a sign. The sign number shall be consistent with the blind flange number on the blind flange location diagram. The unit where the work area is located or the grassroots unit, and the unit in charge of the work point shall confirm and record each blind flange.

Article 7 Before performing blind flange removal and plugging operations on pipelines shared with external enterprises, relevant upstream and downstream units should be notified.

Article 8. During operations, the pressure at the work site should be reduced to atmospheric pressure, and a designated person should be assigned to monitor the operation. If the monitor discovers any situation that endangers the safety of the workers, the operation should be stopped immediately, and the personnel should be guided to evacuate to a safe area. The unit where the work area is located should send a local supervisor.

Article 9 When performing blind flange removal and installation operations in flammable and explosive locations, operators shall wear anti-static work clothes and work shoes, and shall use explosion-proof lighting and explosion-proof tools; no hot work shall be carried out within 30m of the blind flange removal and installation operation location.

Article 10. Two or more pipeline opening (blind flange removal/plugging) operations shall not be carried out simultaneously on the same pipeline. Separate blind flange removal/plugging operation permits shall be obtained for each operation on the same blind flange. One operation permit may only be used for one blind flange.

Article 11. Workers shall operate from upwind and shall not face directly towards the medium or energy release point of the opened pipeline. Forced ventilation measures shall be implemented in poorly ventilated work areas to prevent the accumulation of flammable or toxic gases. If necessary, roadblocks or warning lines shall be set up in the area affected by the pipeline opening to control access by unauthorized personnel.

Article 12. Verify that the upstream and downstream valves of the blind flange removal/plugging operation point are effectively isolated and locked with tags; the blind flange should be installed on the other side of the valve with material supply, and qualified gaskets must be installed on both sides of the blind flange, and all bolts must be tightened in place. Before removing the blind flange, it should be confirmed that the equipment and system meet the conditions for commissioning.