Views: 0 Author: Site Editor Publish Time: 2024-11-12 Origin: Site
The welding quality control of large storage tanks should be carried out from many aspects, whether it is the inspection of equipment or the management of the process can not be ignored. The following is an analysis of how to control the welding quality of large storage tanks.
This is the basis of the work, we must regularly check the welding machine, argon meter and other measuring tools, qualified before use, at the same time to do a good job of equipment maintenance and maintenance work; Check the welding torch and argon hose in time, and replace it immediately if it is damaged. It is necessary to ensure that all welding equipment in the whole working process is in a qualified, reliable and practical state.
1. Implement programmatic management mode and quality assurance supervision
All welding activities in the project shall be guided and regulated in accordance with the corresponding procedures, and the quality assurance supervision procedures shall be followed throughout the process. Welding construction is more special, to regularly check its reliability, the key is to see whether the procedure is in line with, as well as the reliability of the construction, to ensure that the construction procedure is within the scope of control.
2. Establish reasonable procedures
According to the requirements of engineering design specifications and process evaluation standards, reasonable guidance procedures should be prepared to explain the steel grades, welding standards and position processes used to guide the subsequent construction work.
3. Make good weld records
All welds of large storage tanks and other equipment should be recorded and tracked throughout the whole process, and if conditions permit, the record chart of the welding joint should be drawn, and the welding seam involved should be identified. The weld number is the basis for weld record and computer management. Each welding joint and each process as well as the various inspections and inspections carried out can be checked on the weld record sheet, and the weld record shall be consistent in the drawing, the weld record sheet and the completed welding joint through inspection, and the data shall be submitted to the owner after formation. The weld record sheet mainly has the following functions:
3.1 Record the basic information of the weld, including drawing number, quality plan number, base material and counterpart requirements, welding process, welding material, etc., to guide the on-site construction.
3. 2 Do a good job of recording the site construction and inspection to ensure the traceability of the entire site construction.
3. Ensure the continuity of different processes in the inspection process of the welding machine and implement tracking control of the whole process.
4. Use welding management database
In the welding process, try to make the state of each welding joint within a controllable range, and each welding joint has a record sheet to record its state to ensure the traceability of the welding joint. At the same time, we should also do a good job in the statistical work of engineering quantity and quality data. Compared with other work, this work is more complex and difficult, so it can be combined with the actual development of welding management software for welding records and welding data management. The application of welding software has the following advantages:
4. 1 Manage the weld sheet
Based on the input data, manage the weld record sheet, print and organize it as a centralized management of the quality record report.
4. 2 Process of welding joint management
The whole process of the butt welder, from welding to welding completion, inspection welding and repair procedures are all included in the tracking process to ensure the comprehensiveness of management.
4. 3 File management of welding joints
The welding list and welding process documents of each system should be sorted out and saved to avoid omissions and affect the follow-up work.
5. Take targeted measures to reduce plate deformation
From the site construction situation, there are many reasons for the deformation of large storage tanks, the following is mainly for the current more common reasons to analyze, take targeted measures to eliminate plate deformation.
5.1 The method of unloading materials needs to be improved
At present, the unloading method is to use steel wire rope and iron chain to unload the whole pile of steel plates together, at this time, the following steel plate lifting point contact area is small, the force is large, it is very easy to lead to excessive edge deformation.
To solve this problem, the key is to strengthen the training of on-site unloading personnel, strengthen the protection consciousness of construction personnel for semi-finished products, and strengthen the monitoring of on-site unloading.
5. 2 Improper stacking of plates
The materials used in the welding process of large storage tanks have been piled on the site for a period of time, 80% of the wall panels have not been stacked, and in order to save space and other reasons, the site workers will mix the steel plates of different thickness together, and the thickness of the steel plates is thick, and the deformation is inevitable.
In this regard, we can increase the storage of the wall plate with the same arc, classify the storage of the wall plate shipped to the site, and put the steel plate of the same thickness and the same specification together; There can be no more than nine panels on each harness.
5. 3 Using sledgehammer correction to ensure that the method is accurate
There are many times when sledgehammer is used to correct the welding process, but there are errors in the method. Some construction personnel directly hammer the surface of the wall panel with a sledgehammer, resulting in more dents on the surface of the steel plate, damaging the steel plate coating, and the hammer marks are dense, resulting in poor appearance quality of the wall panel.
For this problem, the construction personnel should do a good job of sledgehammer correction, add 16mm× 100mm×150mm backing plate, and the arc of the backing plate is the same as that of the wall plate; When the sledgehammer is calibrated, the siding is placed on the gear in the same arc as it.
5. 4 No correction before installation
Before the panel installation, the construction personnel did not correct the defects of the steel plate, but used strength to meet the installation requirements, but after welding and removing the anti-deformation fixture, the deformation of the panel exceeded the standard due to the internal stress.
At this time, it is necessary for on-site installation personnel to do a good job of technical disclosure, strengthen the awareness of installation quality, and install by the quality inspector according to the warranty after completion of the correction.
5. 5 The current in the welding is too large
In welding, affected by engineering progress and other factors, the welding current is large, the temperature is large, the heating area is increased, and the deformation will appear.
In response to this problem, it is mainly implemented in accordance with the specifications, reminding welding personnel to pay attention to the welding current used, checking the welding current in time, and strengthening supervision.
5. 6 Welding is not performed in sequence
Welders in the welding, often contrary to the welding order, especially the vertical seam welding is often from the bottom to the top, no step back welding treatment; The welding sequence of the ring seam is 3 to 4 welders evenly arranged, but they are not welded in the same direction. The wrong welding sequence causes the weld to be unevenly heated and unable to release the stress, resulting in welding deformation.
In view of this problem, the key is to improve the working quality of welders, strengthen their sense of responsibility, so that they are serious and responsible in the work, and strengthen the cooperation between employees to ensure the smooth development of the whole work.
6. Check and accept the welding process
In the welding process, it is necessary to strictly follow the relevant specifications, strengthen the implementation of inspection and acceptance work, and ensure the quality of welding. Once the problem is found, it must be repaired. Only in this way can the welding quality of large storage tanks be better promoted. At the same time, it is necessary to achieve clear rights and responsibilities, responsibility to the person, improve the quality awareness of welding personnel, strengthen their sense of responsibility, and fundamentally ensure the quality of welding.
