The spiral tubes are generally not allowed to put so much stock in the production workshop in the use of the square hand, which requires the dealers to place some stocks. However, dealers generally do not have large indoor libraries. Most of them are outdoor warehouses. The spiral pipes are inevitable to keep the sun. So, how to distinguish the rust and rust of the spiral tube?
The so -called rust, as the name suggests, is a layer of rust that floats to the spiral tube. It can be removed with a towel or other things. Simply put, rust is not rusty, which is normal.
The rust of the spiral tube is a long time. At least one year is more than 1 year, the spiral tube passes through the wind and sun exposure outside the outdoor, and the rusty spiral tube has large and small pit on it. This is also a spiral tube rust and rust. A big difference.
The spiral tube is a sawing section of the steel plant tube, and then heated in the ring furnace-perforation-fixed diameter-school straight-cooling-drama head-packaging becomes a qualified finished product. Use the outer diameter*wall thickness. If the spiral tube has single -sided welding and double -sided welding, the welded pipe should ensure the hydraulic test, the tensile strength of the weld, and the cold bending performance.
