What are the technical measures for pipeline anti-corrosion, insulation, and anti settlement?

As the core transportation carrier of building infrastructure, industrial production, and urban public utilities, pipelines are widely used in various fields such as water supply and drainage, gas, heat, petrochemicals, etc. Their operational stability directly affects engineering safety, efficient energy transmission, and environmental safety. During long-term use, pipelines are susceptible to factors such as soil corrosion, medium erosion, temperature changes, and geological settlement, leading to corrosion damage, insulation failure, pipeline deformation, and even fracture. This not only affects transportation efficiency but may also cause leaks, safety accidents, and increase maintenance costs in the later stages. The technical measures for pipeline anti-corrosion, insulation, and anti settlement are the core support to ensure the long-term stable operation of pipelines. It is necessary to combine the pipeline material, conveying medium, laying environment, and geological conditions, follow the principles of scientific adaptation, long-term protection, and precise control, and build a comprehensive protection system. Based on industry standards and engineering practices such as the "Code for Construction of Industrial Metal Pipeline Engineering" (GB50235-2010) and the "Code for Construction and Acceptance of Urban Heating Network Engineering" (CJJ28-2014), the core technical measures for pipeline anti-corrosion, insulation, and anti settlement are coordinated around three modules, with each measure interconnected and complementary to ensure safe, efficient, and sustainable pipeline operation.
The technical measures for pipeline anti-corrosion, insulation, and anti settlement follow the core principles of "prevention first, classified measures, full process control, and long-term adaptation". The core goal is to resist corrosion, reduce heat loss, control settlement and deformation through targeted technical means, ensure stable performance of the pipeline during the design service life, and balance protection effect and economy. The selection of technical measures should be based on the pipeline laying method (buried, overhead, indoor), the characteristics of the conveying medium (high temperature, high pressure, corrosiveness), and the geological environment, to avoid blind application and ensure that the measures are scientifically feasible and effective.

Pipeline anti-corrosion technology measures are the foundation for preventing pipeline corrosion and extending pipeline service life. The core is to block the contact between corrosive media and pipeline metal surfaces through physical isolation, chemical protection, and other methods. According to the pipeline laying environment and corrosion level, suitable anti-corrosion technologies are selected, focusing on surface treatment, anti-corrosion layer construction, and auxiliary anti-corrosion.

Surface treatment is a prerequisite for pipeline anti-corrosion, and the core requirement is to remove impurities such as rust, oxide scale, oil stains, dust, etc. on the surface of the pipeline, ensure that the anti-corrosion layer is tightly adhered to the pipeline surface, and avoid the anti-corrosion layer falling off, bulging, and losing its protective effect due to surface impurities. Common surface treatment methods include sandblasting, manual rust removal, and mechanical rust removal. Sandblasting rust removal is suitable for large-area pipeline treatment, and the rust removal grade should reach Sa2.5 or above to ensure that the pipeline surface is free of visible rust and oxide scale, presenting a uniform metallic luster; Manual rust removal and mechanical rust removal are suitable for local treatment or complex parts, and the rust removal grade should reach St3 to ensure that the surface is free of loose rust and oil stains. After the surface treatment is completed, the surface dust should be cleaned in a timely manner, and the anti-corrosion layer should be applied within 4 hours to prevent the pipeline surface from rusting again. At the same time, the moisture content of the pipeline surface should be controlled to avoid moisture affecting the adhesion of the anti-corrosion layer.

The construction of anti-corrosion layer requires the selection of suitable anti-corrosion materials and construction processes according to the pipeline corrosion environment. Common anti-corrosion layers include coating anti-corrosion, anti-corrosion coil, cathodic protection, etc., which can be used separately or in combination. Coating anti-corrosion is suitable for various types of pipelines. Common coatings include epoxy coal tar coatings, polyurethane coatings, fluorocarbon coatings, etc. The construction adopts a "multi pass thin coating" method, with each coating having a uniform thickness and a total thickness that meets the design requirements, ensuring that the coating is dense, leak free, and pinhole free; Anti corrosion rolls are suitable for buried pipelines, commonly using polyethylene anti-corrosion rolls and polypropylene anti-corrosion rolls. During construction, it is necessary to ensure that the rolls are tightly adhered to the surface of the pipeline, the overlap width meets the specifications, and the interface is tightly sealed to prevent soil corrosive media from infiltrating.

Auxiliary anti-corrosion measures are mainly aimed at buried pipelines and environments with strong corrosiveness. Cathodic protection is divided into forced current cathodic protection and sacrificial anode cathodic protection. Forced current cathodic protection is suitable for long-distance buried pipelines. By applying external current, the pipeline becomes a cathode to prevent corrosion; Sacrificial anode cathodic protection is suitable for short distance pipelines or local areas. Sacrificial anode materials such as zinc alloy and aluminum alloy are selected to form a primary battery with the pipeline, and the pipeline is protected by sacrificial anode materials. In addition, buried pipelines can be wrapped with geotextile and fine sand outside the anti-corrosion layer to reduce the damage of soil friction to the anti-corrosion layer and further enhance the anti-corrosion effect.

The core of pipeline insulation technology measures is to reduce the heat loss of the medium inside the pipeline, prevent condensation and freezing on the surface of the pipeline, and protect the pipeline from external environmental influences. It is suitable for high-temperature medium transportation pipelines, low-temperature pipelines, and outdoor pipeline laying. The technical points revolve around the selection of insulation materials, insulation layer construction, and protective layer construction to ensure that the insulation effect meets the standard.

The selection of thermal insulation materials needs to take into account the thermal insulation performance, high temperature resistance, corrosion resistance and economy. Common thermal insulation materials include rock wool, glass wool, polyurethane foam, polystyrene foam, etc. High temperature pipes (with a temperature of more than 100 ℃) give priority to rock wool, glass wool and other high temperature resistant materials, and low temperature pipes use polyurethane foam and other materials with good thermal insulation effect; Insulation materials should have good compressive strength and hydrophobicity to avoid reducing insulation performance after absorbing water. After entering the site, sampling and retesting should be carried out to ensure that thermal conductivity, density and other indicators meet the specifications.

The construction of insulation layer requires strict control of the construction process. For overhead pipelines, winding or coating insulation can be used, while for buried pipelines, prefabricated insulation pipes or on-site pouring of insulation layer can be used. Spiral insulation should ensure that the insulation material is tightly wrapped without gaps, and the overlap width should be controlled within 50-100mm. Smearing insulation should be evenly applied and constructed in layers, with each layer thickness controlled within 20-30mm to avoid cracks and hollowing; The construction of prefabricated insulation pipes must ensure that the interface insulation is tight and sealed with specialized sealing materials to prevent heat loss. After the completion of the insulation layer construction, the protective layer construction needs to be carried out. The protective layer should be made of galvanized iron sheet, aluminum sheet or waterproof roll to prevent the insulation layer from being damp or damaged. During construction, it is necessary to ensure that the protective layer is flat, sealed, and free of damage or looseness.

The anti settlement technical measures for pipelines are the key to preventing deformation and fracture caused by geological settlement and load effects. The core is to optimize the laying process, strengthen foundation support, and control settlement deformation to ensure that the pipeline remains intact during use. The technical points cover four aspects: laying foundation treatment, pipeline fixation, settlement monitoring, and emergency response.

Laying foundation treatment is the core of anti settlement, and the foundation design needs to be optimized according to geological conditions. For soft soil foundation and backfilled soil foundation, foundation reinforcement treatment is required. Common reinforcement methods include replacing cushion layer, compacting reinforcement, CFG pile reinforcement, etc. The replacement cushion layer is made of graded sand, gravel, lime soil and other materials, and compacted layer by layer to ensure that the foundation bearing capacity meets the design requirements; Compaction and reinforcement should control the compaction coefficient to be no less than 0.95 to reduce the amount of foundation settlement. When laying pipelines, a sand cushion layer should be laid with a thickness controlled between 10-15cm to ensure uniform stress at the bottom of the pipeline and avoid local deformation caused by excessive stress.

Pipeline fixation should be based on the laying method and diameter of the pipeline, and reasonable supports, hangers, and fixed piers should be set up. The spacing between supports and hangers for overhead pipelines should meet the requirements of the specifications to ensure uniform stress distribution and avoid pipeline displacement caused by vibration; Fixed piers shall be installed at heavily stressed areas such as bends and tees in buried pipelines to prevent stress concentration caused by settlement and displacement, which may lead to pipeline fracture. For long-distance buried pipelines, expansion joints should be installed to absorb the deformation caused by temperature changes and settlement, and to avoid damage to the pipeline due to stress.

Settlement monitoring is an important guarantee for preventing settlement, and it is necessary to establish a regular monitoring mechanism. After the pipeline laying is completed, settlement monitoring points should be set up to regularly monitor the settlement of the pipeline. The monitoring frequency should be determined based on geological conditions and pipeline operation. If the settlement exceeds the allowable range of the specifications, timely adjustment measures should be taken. Common monitoring methods include leveling measurement, displacement monitoring, etc. Monitoring data needs to be sorted and analyzed in a timely manner to grasp the settlement law of pipelines and predict hidden dangers in advance.

Emergency response needs to develop special emergency plans for deformation, damage, and other issues caused by pipeline settlement. When hidden dangers such as excessive pipeline settlement or cracks are discovered, transportation operations should be stopped in a timely manner, and measures such as reinforcement and resetting should be taken to avoid the expansion of hidden dangers. For pipelines with severe settlement, local replacement and re laying are necessary to ensure that the pipelines resume normal operation.

The implementation of anti-corrosion, insulation, and anti settlement technical measures for pipelines needs to run through the entire process of pipeline design, construction, and operation, with coordinated control at all stages, strict adherence to industry standards, and optimization of technical solutions based on actual engineering conditions. During the construction process, it is necessary to strengthen the control of material quality and construction technology, conduct quality inspections of each process, ensure that the construction quality of the anti-corrosion layer and insulation layer meets the standards, and ensure that the foundation treatment is in place; During the operation phase, it is necessary to establish a regular inspection and maintenance mechanism, regularly check the integrity of the anti-corrosion layer, insulation layer, and pipeline settlement, and promptly rectify hidden dangers.

With the application of new protective materials and intelligent monitoring technology, the refinement and standardization level of pipeline anti-corrosion, insulation, and anti settlement technology continues to improve. Targeted implementation of various technical measures can not only extend the service life of pipelines and reduce maintenance costs, but also ensure the safety of pipeline transportation and avoid safety accidents such as leaks, providing strong support for the high-quality development of industrial production and urban public utilities.