The cs seamless pipe substrate undergoes complex physical and chemical reactions with the molten plating solution to form a corrosion-resistant zinc-iron alloy layer with a tight structure. The alloy layer is integrated with the pure zinc layer and the steel pipe substrate, so its corrosion resistance is relatively high powerful. It is precisely because of the advantages of corrosion resistance and long service life of galvanized seamless pipes that with the continuous improvement of building quality requirements, the service life and strength requirements of pipeline systems are also getting higher and higher. Galvanized seamless pipes often replace ordinary galvanized pipes and are used in pipeline systems with higher requirements for fire protection, air conditioning and other circulating water and gas medium transportation.

CS seamless pipe galvanizing process

Black tube - alkali washing - water washing - pickling - water rinsing - dipping aid - drying - hot dip galvanizing - external blowing - internal blowing - air cooling - water cooling - passivation - water rinse - inspection - weighing - storage

1. The pre-plating treatment process includes 5 processes: alkali washing, acid washing, rinsing, dipping aid, and drying.

1) Some steel pipes have oil stains on the surface and need to be cleaned with alkali.
2) Use ophthalmic acid for pickling to remove the oxide skin on the surface of the steel pipe.
3) In order to remove the residual acid and iron salt attached to the surface of the steel pipe, the steel pipe needs to be rinsed twice.
4) The function of the flux is to remove all impurities from the surface of the steel pipe, to ensure the clean contact between the steel pipe and the zinc liquid, and to form a good coating.
5) In order to prevent the steel pipe from being immersed in the zinc pot, the steel pipe needs to be dried. The drying temperature is 120-200 °C, and the drying time is not less than 150s.

2. Hot dip galvanizing process

1) The temperature of the zinc liquid in the zinc pot is strictly controlled at 450±5℃.
2) The dried steel pipes are removed one by one through the drying furnace chain, immersed in the furnace roller table, then transported to the galvanizing furnace, and rolled into the three galvanizing spirals in the galvanizing machine.
3) The phases of the three spirals are different, so that the steel pipe is inclined on the spiral. With the rotation of the spiral, the steel pipe moves downward and forms an inclined angle, and then enters the zinc liquid and continues to move downward.
4) The steel pipe automatically falls on the slide rail in the zinc pot, and is moved to the outside by the feeding mechanism, and then the zinc liquid is lifted out by the pipe lifting machine.
5) When the steel pipe is lifted to the surface of the magnetic roller, it is sucked and moved to the pull-out roller table.

3.The post-plating treatment process includes: external blowing, dragging out, internal blowing, water cooling, inspection, passivation, and printing.

1) The steel pipe passes through the outer blowing ring, which has a row of small holes. Through compressed air, the excess zinc liquid of the steel pipe is blown away to obtain a smooth appearance.
2) Under the condition of satisfying the production rhythm, reducing the dragging speed can control the amount of zinc and reduce the consumption of zinc.
3) Internal blowing can remove the excess zinc liquid on the inner surface of the steel pipe to obtain a smooth inner surface. The removed zinc liquid forms zinc powder and is recycled.
4) The temperature of the water cooling tank is controlled at 80°C, and the cooling water is pumped to the cooling tower for cooling and then recycled.
5) After water cooling, move out of the water cooling tank and land on the inspection bench. After inspection, put the leaked plating tube into the waste basket, and the finished tube will be sent to the output roller table.
6) The finished pipe is sprayed and blown with passivation liquid during transportation to passivate the surface of the pipe. After the outer ring is blown, the excess passivation liquid is blown off with compressed air.
7) During the conveying process, the drying rack with steam heating pipe row is laid, and after drying, printing and packaging are carried out.

The use of galvanized seamless pipe

Galvanized seamless pipe is a welded steel pipe with a hot-dip galvanized or electro-galvanized layer on the surface. Galvanizing can increase the corrosion resistance of steel pipes and prolong the service life. Galvanized pipes are widely used. In addition to being used as pipeline pipes for general low-pressure fluids such as water, gas, and oil, they are also used as oil well pipes and oil pipes in the petroleum industry, especially in offshore oil fields, and oil heaters and condensers in chemical coking equipment. Pipes for coolers, coal distillation washing oil exchangers, and pipes for trestle piles, supporting frames for mine tunnels, etc.