First, safety precautions
1. It is strictly forbidden to stand under the primary straight-through valve of the steam boiler pipeline drain. 2. There is no one within 1 meter in the diameter of the outlet of the drainpipe at each drain point. 3. There is no one within 50 meters of the outlet direction of the main outlet valve. 4. The purging must be carried out after being ordered by the construction commander. 5. Keep communication smooth. 6. The operator must wear safety gloves.
Second, the purge procedure: the purge command is issued by the commander-in-chief
1. Before purging, the person in charge of each point should do the following work:
a) Check the bracket for damage.
b) Open the primary drain valve, primary drain bypass valve, and secondary drain bypass valve of each drain steam boiler pipeline on the pipeline, and close the front stop valve of the trap.
c) Make original records and punctuation of all sliding brackets, record the expansion of the pipes when the pipes are warmed, observe the fixed brackets and make records.
d) Open the purge outlet valve slightly.
2. Slowly open the steam boiler supply valve, warm the steam boiler supply pipe, and check the drainage condition of each drainage point, the action of the compensator, and the bracket.
3. After confirming that there is no abnormality in the inspection of each point, report to the commander-in-chief, slowly open the large steam boiler supply valve again to further warm the pipe and then check the drain points one by one along the pipeline until the 1# drain point is free of debris, and the bus is closed. main valve.
4. Close the primary straight-through valve after the steam boiler pipeline drains the primary straight-through valve without draining.
5. After confirming that the primary straight-through valves of the stream pipeline are all closed, report to the commander-in-chief.
6. Slowly open the main steam boiler supply valve again to warm the pipes. The heating time is 20-30 minutes, and check the drain points one by one along the pipeline. After the second bypass valve of the 1# drain point has no drain, close the secondary bypass of the small drain. road valve. 7. Close all traps when the command warmer is over.
8. Gradually increase the pressure to 0.80Mpa for 20 minutes.
9. After the end of the pressure stabilization, slowly open the temporary outlet control valve to gradually increase the flow rate to 30m/s, and purge for 20 minutes.
10. After the purging is over, close the temporary outlet control valve and issue a warning, replace the blind plate, open the drain, and wait for the next purging.
11. Wait for the temperature of the pipe wall to drop below 100°C and the pressure is 1.5Mpa before performing the above (1-7) purging steps (the hydrophobic bypass cannot be opened once), the gasket is required to be flat and the blind plate device is in a qualified position. The collection of impurities on the board will end when the blind board is qualified.
12. After purging, remove the temporary connection.
13. Organize records and report to the commander and commander-in-chief.
Third, if the following faults are found during purging, report to the commander-in-chief immediately and stop purging.
1. The steam boiler pipe was ruptured in a large area, and the steam boiler overflowed in large quantities. 2. Large-area displacement of the bracket and the steam boiler pipeline is pushed away from the bracket. 3. Severe water hammer in the steam boiler pipeline.
Fourth, the matters needing attention in purging:
1. During the purging process, it is necessary to strengthen the contact with the centralized control personnel to control the steam boiler pressure and steam boiler temperature. 2. During the second purging, special care should be taken to prevent the recoil force from destroying the stability of the piping system. The purging control valve should be opened slowly, and the reaction at the outlet of the purging steam boiler pipeline should be closely watched. If there is any abnormality, the purging control valve should be closed immediately until the abnormality is eliminated. After that, it can be purged again.