Spiral steel pipe is a spiral seam steel pipe made of strip steel coil as raw material, often warmly extruded, and welded by automatic double-wire double-sided submerged arc welding process. The spiral steel pipe feeds the strip into the welded pipe unit. After rolling by multiple rollers, the strip is gradually rolled up to form a circular tube blank with an opening gap. 3mm, and make both ends of the welding joint flush.
When the spiral steel pipe manufacturer produces the spiral steel pipe, the length is usually 12 meters, and the length deviation of the steel pipe delivered according to the fixed length should be within the range of plus or minus 500 mm. The yield of the production of fixed-length pipes is significantly lower than that of ordinary length pipes, and it is reasonable for the manufacturer to ask for a price increase. The price increase varies from company to company, but it is generally about 10% higher than the base price.
The fixed length should be within the usual length range, which is a certain fixed length dimension required in the contract. However, in practice, it is impossible to cut out the maximum fixed length, so the standard stipulates the allowable positive deviation value for the fixed length.
If there are no provisions for length deviation and cutting allowance in the standard, it should be negotiated by both parties and indicated in the contract. The double-length scale of the spiral steel pipe is the same as the fixed-length length, which will bring a significant reduction in the finished product rate to the manufacturer. Therefore, the manufacturer’s proposal to increase the price is reasonable, and the rate of increase is basically the same as that of the fixed-length length.