Low-lying corrosion-resisting alloying corrosion-resisting heat-preservation pipeline and processing technology thereof

Abstract

The invention discloses a low-lying corrosion-resisting alloying corrosion-resisting heat-preservation pipeline and a processing technology thereof. The low-lying corrosion-resisting alloying corrosion-resisting heat-preservation pipeline comprises a steel pipe (1), a multi-component alloy corrosion-resisting layer (2), a polyurethane insulation coating layer (3) and a polyethylene protective layer (4), and the problem that heat preservation pipelines are prone to corrosion is solved. The processing technology of the low-lying corrosion-resisting alloy corrosion-resisting heat-preservation pipeline comprises the following steps that firstly, the impeller blasting process is conducted on the surface of the steel pipe; secondly, Zn and Al are fused in a furnace hearth; thirdly, the steel pipe is soaked in the furnace hearth; fourthly, the steel pipe is shifted to a thermal spraying working position; fifthly, a Zn-Ni surface layer is manufactured through thermal spraying, and the Zn-Al-Ni multi-component alloy corrosion-resisting layer is formed; sixthly, a machine head is formed through a one-step method, and a polyurethane protecting layer and the polyethylene protecting layer are obtained in a synchronized mode. The low-lying corrosion-resisting alloying corrosion-resisting heat-preservation pipeline is simple and reasonable in processing technology, saves energy, and has the advantages of being high in corrosion-resisting performance and long in service life.

Description

technical field [0001] The invention relates to the field of pipelines, in particular to thermal insulation pipelines used in oil fields, in particular to a low-lying corrosion-resistant alloyed anti-corrosion thermal insulation pipeline and its processing technology. Background technique [0002] The Northeast Songnen Plain is the largest oil-producing area in my country. It is located in the high-latitude alpine region of the northern temperate zone. As a continental oilfield soil, the soil has a high salt content. About 15% of the gathering and transportation pipelines need to be laid in low-lying areas, swamps and other strong corrosion areas. , the soil environment conditions are harsh, and the groundwater level is high. When the anti-corrosion layer of the pipeline is partially damaged or aged, a large cathode (non-destructive area) and a small anode (damage point) are formed. The metal pipeline part as the anode is due to this electrochemical corrosion. Lead to p...

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Problems solved by technology

[0002] The Northeast Songnen Plain is the largest oil-producing area in my country. It is located in the high-latitude alpine region of the northern temperate zone. As a continental oilfield soil, the soil has a high salt content. About 15% of the gathering and transportation pipelines need to be laid in low-lying areas, swamps and other strong corrosion areas. , the soil environment conditions are harsh, and the groundwater level is high. When the anti-corrosion layer of the pipeline is partially damaged or aged, a large cathode (non-destructive area) and a small anode (damage point) are formed. The metal pipeline part as the anode is due to this electrochemical corrosion. Causes perforation corrosion and reduces service life of insulation pipes

[0003] In order to prolong the service life of thermal insulation pipelines in low-lying and swampy areas, the cathodic protection technology of impressed current or sacrificial anode was usually used in the past. The impressed current method requires a continuous external power supply, and the maintenance power supply cost is high, and it is caused by stray currents in low-lying and swampy areas. Over-protection will cause damage to the anti-corrosion layer and hydrogen embrittlement of the pipe. Although the sacrificial anode is maintenance-free, it still has the problem of reducing the protective effect at points far away from the anode. In recent years, an electrochemical insulation pipe has also appeared in China. It mainly forms an alloy coating and realizes full coverage of the old oil pipe base material. It is only suitable for use in the secondary corrosion environment of ordinary soil. It is used in swamps and low-lying areas with high saline and alkali content. The zinc and aluminum atoms are used as The consumption of anode materials is accelerated, and there are problems of premature powdering and aging of the coating, which shortens the service life. Therefore, it is of great significance to meet the new structure engineering of anti-corrosion and heat preservation under special geographical and geological conditions

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