There are two kinds of galvanizing: hot-dip galvanizing (hot-dip galvanizing) and cold galvanizing (electro-agalvanizing). The cost of electro-galvanizing is low, the surface is not very smooth, and its corrosion resistance is much different than that of hot-dip galvanized pipes. How to test the quality of galvanized pipe?
According to the standard requirements,
Galvanized Pipe Factory
It is pointed out that the inspection content of the geometric dimension of the galvanized square pipe mainly includes the wall thickness, outer diameter, length, curvature, ovality, and end face shape of the galvanized square pipe.
1. Wall thickness inspection
The tool used for wall thickness inspection is mainly a micrometer. During the inspection, use a micrometer to measure the wall thickness of the galvanized square pipe one by one. Before the inspection, first, verify whether the certificate of the micrometer is within the validity period, and check whether the micrometer is aligned with the zero position, whether the rotation is flexible, the measuring surface should be free of scratches and rust spots, and it can be used only after it is qualified. During the inspection, hold the micrometer bracket with the left hand and rotate the exciting wheel with the right hand. The diameter of the screw rod should coincide with the diameter of the measuring point, and the end face measurement should be no less than 6 points. If the wall thickness is found to be unqualified, it should be marked.
2. Outer diameter and ovality inspection
The tools used for outer diameter and ovality inspection are mainly calipers and vernier calipers. During the inspection, measure the outer diameter of the galvanized square tube one by one with a qualified caliper. Before the inspection, first, verify whether the certificate of the caliper is within the validity period, use the vernier caliper to calibrate the used caliper, and check whether there are scratches and rust on the measuring surface. During the inspection, the caliper should be perpendicular to the axis of the galvanized square pipe, the galvanized square pipe should be rotated slowly, and the maximum and minimum points of the section where it is located should be measured. If the outer diameter is found to be too large or too small, a mark should be made.
3. Length check
The tool used to check the length of the galvanized square pipe is mainly a steel tape measure. When measuring the length, the "O" point of the tape measure is aligned with one end of the galvanized square pipe, and then the tape measure is tightened so that one side of the tape measure is close to the surface of the galvanized square pipe. The length of the tape measure at the other end of the galvanized square pipe is the length of the galvanized square pipe.
4. Bending inspection of galvanized square tube
The bending degree inspection of galvanized square pipe is mainly to check the total length of the galvanized square pipe and the bending degree per meter. The tools used are mainly level, feeler gauge, and fishing line. When measuring the total curvature of the galvanized square pipe, use a fishing line to align one end of the galvanized square pipe, then pull the fishing line so that one side of the fishing line is close to the surface of the galvanized square pipe, and then measure the galvanized square pipe with a feeler gauge The distance between the surface and the maximum gap between the fishing line, the measured maximum distance is the total length of the galvanized square tube.
