Specifications Analysis of SAWH Steel Pipe
Update:2016-12-13 View(s):2541 Keywords :
1, Uneven wall thickness: pipe wall thickness can not throughout the same objective wall thickness ranges phenomenon exists in its cross-sectional and longitudinal tubular body, ie uneven thickness. In order to control this unevenness in some steel standards specified in the uneven wall thickness allows indicators, generally at no more than 80% of the wall thickness tolerance (negotiated by both sides after execution).
2, Ellipticity: circular in cross-section of the pipe outside diameter ranging phenomenon exists, i.e., there are not necessarily mutually perpendicular maximum outer diameter and the smallest outer diameter, the difference between the maximum and minimum outer diameter to outer diameter is ovality (or roundness). In order to control the ellipticity some steel standards specified allowable ovality the index, generally defined as no more than 80% of the diameter tolerance (consultation by both sides after the execution).
3, Bending:SAWH steel pipe in the longitudinal direction of the curved shape, with its figures showing the degree of the curve that is called curvature. Curvature specified in the standard is generally divided into the following two:
A, the local curvature: Using a meter long ruler * maximum amount of pipe bends, measuring the chord high (mm), is the local bending degree value in units of mm / m, representation as 2.5mm / m . This method is also applicable to the bending of the tube end.
B, full-length total curvature: use a piece of string from both ends of the tube taut, measuring pipe bend chord maximum height (mm), and then converted into a length (meters) percentage, is the length of pipe direction the total length of curvature.
4, Difference sizes: size tolerance or called standard size exceeds allowable deviation. Here, "size" mainly refers to the outer diameter and wall thickness of steel pipe. Usually someone Oversize habit called "tolerance outrageous," and that the deviation is called tolerance equated imprecise, should be called "deviation outrageous." Deviation here may be "positive", it may be "negative", rarely "positive and negative" deviation outrageous phenomenon in the same batch of steel pipe.