Why are plastic-coated steel pipes the preferred choice for wastewater treatment

First, the superior performance of plastic-coated steel pipes for wastewater treatment:

(I) Superior corrosion resistance of plastic-coated steel pipes for wastewater treatment:

Wastewater treatment is a complex and challenging task. Wastewater has an extremely complex composition, often containing various acids, alkalis, salts, and organic substances, such as sulfuric acid, hydrochloric acid, sodium hydroxide, sodium chloride, and various organic acids and alkalis. These components can severely corrode pipelines. Ordinary pipes, under such conditions, may experience thinning of the pipe wall and perforation within a short period, seriously affecting the normal operation of the wastewater treatment system. The development of plastic-coated steel pipes provides an effective solution to this problem. Its surface coating acts like a sturdy armor, effectively resisting the erosion of various corrosive substances in wastewater.

(II) High mechanical strength of plastic-coated steel pipes for wastewater treatment:

In wastewater treatment systems, pipelines need to withstand various external forces, such as soil pressure, vibrations from ground traffic, and collisions during construction. The steel pipe substrate of the plastic-coated steel pipe provides it with stable support, giving it good mechanical strength and enabling it to withstand greater pressure and impact without deformation or damage. Thanks to its high-strength steel pipe substrate, the plastic-coated steel pipe can easily cope with these external forces, ensuring the pipeline maintains its structural integrity during long-term use.

(III) The inner wall of plastic-coated steel pipes for sewage treatment is smooth and not prone to scaling.

Sewage usually contains a large amount of suspended solids, impurities, and microorganisms. These substances easily adhere to the pipe wall during pipeline transportation, forming scale, which reduces the inner diameter of the pipe, increases water flow resistance, and affects the efficiency of sewage treatment. The inner wall of the plastic-coated steel pipe undergoes special treatment, making it extremely smooth with very low roughness. This allows sewage to flow smoothly through the pipe, greatly reducing resistance. At the same time, the smooth inner wall is not conducive to the adhesion and accumulation of scale, effectively preventing scaling.

(IV) Plastic-coated steel pipes for sewage treatment ensure water quality.

In the sewage treatment process, the growth and reproduction of microorganisms is a common problem. If left uncontrolled, these microorganisms will form a biofilm inside the pipes, affecting water quality and potentially causing corrosion and blockages. The plastic coating on plastic-coated steel pipes undergoes special treatment, possessing antibacterial and anti-algae properties, effectively inhibiting the growth and reproduction of microorganisms.

Secondly, plastic-coated steel pipes for wastewater treatment come in a variety of specifications.

The specifications and models of plastic-coated steel pipes are diverse, with common nominal diameters (DN) ranging from the smaller DN15 to the larger DN1660, all measured in millimeters. There are also various options for outer diameter and wall thickness, with wall thickness generally between 1.0 and 2.5 mm. However, customization is also possible based on different usage needs and industry requirements. In practical applications, the appropriate specification needs to be selected based on factors such as the flow rate, pressure, and installation site of the wastewater treatment system. If the wastewater flow rate is large, a plastic-coated steel pipe with a larger inner diameter is required to ensure smooth wastewater flow and prevent blockages. For high-pressure wastewater treatment systems, such as some industrial wastewater treatment facilities, a thicker-walled plastic-coated steel pipe is necessary to ensure the pipe can withstand the corresponding pressure and prevent pipe rupture. In addition, the size of the installation site also affects the choice of specifications. In situations with limited space, smaller-sized plastic-coated steel pipes may be necessary for easier installation and construction.

Third, Installation and Maintenance of Plastic-Coated Steel Pipes for Wastewater Treatment

(I) Installation Process and Key Points of Plastic-Coated Steel Pipes for Wastewater Treatment.

Plastic-coated steel pipes can be installed in various ways, commonly including threaded connections, flange connections, and grooved connections. Each connection method has its unique applicable scenarios and operational points. Threaded connections are generally suitable for plastic-coated steel pipes with smaller diameters.

When making threaded connections,

(1) A professional threading machine should be used to thread the ends of the steel pipe. The accuracy and quality of the threading directly affect the tightness of the connection.

(2) After threading, carefully clean the iron filings and debris from the threads to prevent them from entering the pipe and affecting water quality and the normal operation of the pipeline.

(3) When connecting, apply a sealant, such as sealant or PTFE tape, evenly to the threads to enhance sealing performance and prevent leakage.

(4) Tighten the pipe fittings to the plastic-coated steel pipe using threads. During tightening, ensure an even force to avoid damaging the threads or deforming the pipe due to excessive force.

Flange connections are suitable for pipes with larger diameters or those requiring high sealing performance. When connecting flanges,

(1) First, weld flanges to both ends of the steel pipe. During welding, ensure the flanges are perpendicular to the steel pipe and that the welds are firm, without defects such as incomplete welds or missed welds.

(2) After welding, apply a plastic coating to the flanges to ensure their corrosion resistance.

(3) During installation, install a gasket between the two flanges. The gasket material should be selected based on the properties and temperature of the medium being transported to ensure its sealing performance and corrosion resistance.

(4) Tighten the two flanges tightly with bolts. The bolts should be tightened diagonally to ensure even stress on the flanges and a good seal.

Groove connections are a relatively convenient connection method and are widely used on construction sites. When performing grooved connections

(1) A dedicated grooving machine should be used to roll grooves into the ends of the steel pipe. The depth and width of the grooves must meet relevant standard requirements to ensure the fitting accuracy with the grooved fittings.

(2) During the grooving process, care should be taken to control the pressure and speed of the grooving machine to avoid damaging the coating of the steel pipe.

(3) After grooving, a rubber sealing ring should be placed on the grooved part of the steel pipe.

(4) Install the grooved fittings, embedding the inner edge of the clamp into the groove and fixing it in the center of the groove. Finally, tighten the bolts evenly and alternately to ensure the clamp fits tightly against the groove, achieving a sealed connection.

Regardless of the connection method used, special care should be taken to protect the coating of the plastic-coated steel pipe during installation to prevent damage. Handle with care during transport and installation, avoiding collisions between the pipe and hard objects. If the coating is accidentally damaged, it should be repaired promptly. The same material as the pipe coating can be used for repair to ensure the corrosion resistance of the pipe. In addition, after installation, a pressure test must be conducted on the pipeline system to check the sealing of the connections and the pressure resistance of the pipes. Only after ensuring there are no leaks or seepage can the system be put into use.

(II) Daily Maintenance and Precautions for Plastic-Coated Steel Pipes for Sewage Treatment.

Daily maintenance of plastic-coated steel pipes is crucial for ensuring their normal operation and extending their service life. In daily maintenance, the pipes should be cleaned regularly to remove deposits and dirt, preventing blockages. Specialized cleaning agents should be used; avoid using hard brushes to prevent scratching or damaging the plastic coating, which could affect the pipe's corrosion resistance. Regularly checking the pipe connections is also an important part of maintenance. Ensure that the bolts at the connections are tight and not loose, and that the gaskets are intact to prevent leaks. At the same time, a pressure test should be conducted to check the pipe's sealing performance. If there is a pressure drop or leakage, the cause should be identified and repaired promptly.

In addition, corrosion testing of the plastic coating on the pipes is necessary. Using professional testing equipment, the coating should be inspected for damage, peeling, or other issues. If any problems are found, repair or replacement should be carried out promptly. During use, external forces should be avoided to prevent damage to the plastic-coated steel pipes. Guardrails or safety nets should be installed above the pipes to prevent damage from falling objects; protective mats should be laid on sidewalks or other passageways to prevent accidental stepping on the plastic-coated steel pipes. If damage or leakage is found in the pipes, they should be repaired or replaced immediately. Aged or severely damaged plastic-coated steel pipes should be replaced promptly to ensure the normal operation of the sewage treatment system. Proper maintenance can effectively extend the service life of plastic-coated steel pipes, reduce maintenance costs, and ensure the stable operation of the sewage treatment system. Only by performing daily maintenance can the advantages of plastic-coated steel pipes in sewage treatment be fully utilized, providing strong support for environmental protection and the sustainable use of water resources.