Views:2 Author:Site Editor Publish Time: 2019-01-03 Origin:Site
1. Seamless steel pipe supply steel pipe is compared with other traditional pipe materials. The raw materials are light, high in strength, good in patience, able to withstand high internal pressure, sensitive in production, and can be used in messy or bad geological conditions.
2, but the steel pipe has a large rate in the application process, mainly the internal and external anti-corrosion treatment troubles. The question of primary external anti-corrosion is very important, and the quality of its external anti-corrosion directly affects its service life. At present, the external anti-corrosion of domestic steel pipes is mainly: concealed type, and the steel pipes are all requested to be strengthened or specially strengthened external anti-corrosion, and some areas promote cathodic protection. The concealed type of external anticorrosion method is usually a coating such as petroleum asphalt, epoxy coal tar pitch, etc., the latter is not easy to cure at low temperatures, and there are more doubts in the construction of the field welding joint. The chlorosulfonated polyethylene was originally used. Because most of the solvents, easy to produce pinholes, anti-breakdown is not qualified, and some areas are no longer used. Regarding the cathodic protection, its anti-corrosion effect is better, but because of the method of sacrificial anode, the anode must be replaced regularly in the future operation, which increases the running cost and operation.
In addition to the inner wall treatment, there are three methods commonly used for seamless steel pipe supply: anti-corrosion coating, resin mortar, cement mortar. There are two questions in all three methods: The first is the bond strength between the anti-corrosion layer and the steel pipe, which has been said before the cement mortar. Both the anti-corrosion coating and the resin mortar require that the inside and outside of the steel pipe be completely derusted before construction, but this is difficult to achieve. Therefore, the rust point part forms the source of delamination and peeling in the future, which constitutes corrosion and scaling. The second is that most of the steel pipe is on-site butt welding construction, and anti-corrosion is performed after welding. It can only be done manually. The quality is not easy to control, and the tube with a smaller diameter is no longer preserved because the personnel cannot enter the construction. It also forms a hidden danger of future weld damage. According to the analysis of the pipe burst accident of several times of steel pipes, it is mainly formed by the corrosion of welds of low weld quality.
3. The supply of seamless steel pipes is relatively high.
4. Poor hydraulic function and high energy consumption. The in-tube roughness coefficient of the steel pipe is between 0.013-0.014, so that the pipeline with the same pipe diameter has the same resistance along the same water delivery volume, the demand increases the pump head, increases the pre-investment, and the operating cost is consumed. The power is large and it is also greatly increased.
5. The pipeline has the disadvantage of poor bearing capacity for water hammer.