Causes of Thick-walled Pipe Wall Thickness Uneven
Thick-walled steel mainly for the uneven spiral wall is uneven, uneven thickness and head straight rear wall thickness of partial thickness, thin and so on.
Causes of uneven thickness of thick-walled steel spiral punching machine rolling centerline is correct, two rolls of varying inclination or former head reduction and other small adjustment causes uneven, generally along the entire length of the spiral steel pipe like distribution. The main measures is to adjust the punching machine rolling centerline, the inclination angle is equal to two rolls, according to the rolling table given parameter adjustment pipe rolling mill.
Linear uneven thickness because the mandrel pre-worn saddle height adjustment inappropriate mandrel pre-wear when exposed to a side of the capillary, resulting in capillary contact surface temperature drop too fast, resulting in uneven thickness and even pull concave defects. Even rolling roll gap is too small or too large. Pipe rolling mill centerline deviation. Single, double rack reduction uneven direction will cause the pipe rack single thin (thick), dual direction rack thick (thin) of linear symmetry deviation. The main measures are adjusted mandrel pre-worn saddle height guarantee mandrel and capillary pair. Should be replaced rolling pass and the roll gap measurement specifications, so that the actual roll gap and rolling table consistent. Using the optical means rolling centerline adjustment must be corrected rolling machine centerline annual overhaul.
Head, tail uneven thickness because the tube tip cut slope, bend through the large, tube-centering holes errors could easily lead to uneven thickness of the head pipe. Perforation extending coefficient is too large, roll speed is too high, rolling stable. Puncher throwing steel capillary instability could easily lead to the tail of uneven thickness. Measure is to check the quality of steel tube, the front end of the tube to prevent the cut slope, large reduction, replacement or repair should be corrected pass the centering holes. A lower penetration rates, in order to ensure the stability and uniformity of capillary wall thickness rolling. When the roll speed adjustment, matching the guide disc also adjusted accordingly.