There is a kind of flange fittings product in pipe fittings industry. Flange is a kind of equipment connecting pipelines. It has many kinds of classifications, such as national standard, American standard, Japanese standard, non-standard, high and low pressure according to pressure, stainless steel, alloy steel, carbon steel and so on. Today we want to say that this kind of flange is called non-standard forging flange. Non-standard forging flange has certain processing requirements in processing. Let’s go with the threaded pipe fittings manufacturer to understand.
Non-standard forging flange processing requirements:
1. The steel, steel plate material, size and thickness used for non-standard flange processing need to be selected strictly in accordance with the requirements of drawings. The overall weight of each non-standard forged flange should basically conform to the drawings, and the error should not exceed (+5%) and should not be lower than the weight requirements.
2. In the process of welding, the stress concentration area should be avoided to facilitate welding and heat treatment operation.
3. Non-standard forging flange is not suitable for opening operation in welding seam and edge during processing.
4. The distance between two longitudinal welds (adjacent) needs to be 3 times larger than the wall thickness, but not less than 100 mm.
5. The distance between two adjacent longitudinal seams on the same barrel joint should not be less than 200 mm.
6. The selection of welding materials should meet the requirements of drawings and current national standards. The selected welding materials should be sealed and stored to prevent damp deterioration. The storage environment temperature should not be less than 5 C and the relative humidity should not be less than 70%.
7. The groove form and size of the weld shall conform to the requirements of the design documents and the welding operation instructions. In addition to the welds indicated, each weld is a continuous weld, and the foot height is the minimum thickness of the welded piece.
8. Before welding, the groove and its inner and outer surfaces should be cleaned up with no less than 10 mm of oil, paint, scale, rust, burr and galvanized layer, and no cracks, interlayer and other defects should be allowed.
9. It is strictly forbidden to start arc or test current on the base metal surface other than groove, and it is required to prevent the base metal from being scratched by arc.
From the above, it can be seen that the design process of non-standard forging flange is very strict, so that the forging flange can meet the actual needs of users.
