In order to reduce the negative error of the high-pressure alloy tube, we must only deal with the negative error of the high-pressure alloy tube according to the existing situation. For example, the maximum allowable negative public service value of the 8-12 high-pressure alloy tube is -7%, and the calculated internal diameter d must first determine the K value of the negative public service utilization.
If the K value is too small, the negative error scale of the inner diameter will not be fully utilized, and the K value will be too large, and the partial inner diameter scale will be formed beyond the lower limit of the specification rule, and the strength value of the specification rule will not be met and will be judged as unqualified. The existing technical control level, including the average value of the inner diameter and the specification difference, the average value of the intensity, and the specification difference, etc., always determine the K value.
The K value is selected by 30%, and the value of the inner diameter d of the product is determined by the square of the nominal inner diameter of the steel bar plus the experience factor of 1.274 and the negative error utilization of the steel bar, the negative component error component of the steel bar, and the sum of the nominal cross-sectional area of the steel bar. According to the national standard rules, the scale of the transverse ribs and the number of sets of the product before the scrap is used, the number of transverse ribs in the circumferential direction of the reel of the rebar type of the standard German standard is the basis for the supply of the new roll. Timely to the quality inspectors to understand the negative value of the product, and adjust it in time to ensure that the negative public service value is at the central value of the national standard.