What is carbon steel ptfe lined pipe

Carbon Steel PTFE Lined Pipe is a composite pipe, is a PTFE lined pipe product on the inner wall of carbon steel pipe, it combines the structural strength of carbon steel and the excellent chemical stability of PTFE, widely used in the field of corrosive media transportation.

1. Structure and material

Outer carbon steel: Carbon steel has high mechanical strength and bearing capacity, and is a common material in the manufacture of pipes, structural parts and other applications. However, simple carbon steel is prone to corrosion in the face of certain chemical media (such as strong acids, strong alkalis, etc.), resulting in shortened pipeline life and increased risk of leakage. Therefore, when carbon steel pipes are used in corrosive environments, they often need to be coated, and anti-corrosion measures such as coating, lining or galvanizing are applied on the surface or inner wall of the steel pipe to improve the anti-corrosion performance of the steel pipe.

PTFE lining: Polytetrafluoroethylene (PTFE), also known as Teflon, is a polymer material with excellent corrosion resistance and chemical inertia, which is often used in non-stick pan coatings, seals in the chemical industry, pipe linings, etc., while its coefficient of friction is low, able to maintain stable physical properties over a wide temperature range. Using PTFE as the lining can effectively isolate the direct contact between the medium and the steel pipe, thereby protecting the carbon steel from corrosion, and also reduce the friction resistance during fluid transport.

Therefore, carbon steel PTFE lined pipe is a pipeline product that combines the advantages of the two, which not only ensures the structural strength, but also has the characteristics of corrosion resistance and high temperature resistance.

2. Manufacturing process

Surface treatment:
The internal surface of carbon steel was cleaned, rusted and roughened to make the surface have a certain roughness, which is conducive to the adhesion of PTFE coating.
Coating or extrusion:
Common methods include PTFE coating on the inner wall of the steel pipe, and sometimes the use of extrusion molding technology, the PTFE material is heated and injected into the tube, so that it is evenly coated on the inner wall.
High temperature curing/sintering:
The PTFE coated pipe is cured or sintered at high temperature to ensure a good bond between the PTFE layer and carbon steel, improving corrosion resistance and long-term stability.
Quality inspection:
Including thickness uniformity, adhesion, corrosion resistance and other parameters to avoid bubbles or stripping, usually using electrical discharge testing or ultrasonic testing, to ensure that products meet industry standards and use requirements.

3. Core strengths

Corrosion resistance: It can resist the erosion of most chemical substances such as strong acid, strong alkali, organic solvent, and extend the service life of the pipeline, and can work stably even in extreme chemical environments.
Temperature resistance: suitable for high temperature environment, far more than most plastic lining materials.
Low friction resistance: The smooth surface of the PTFE layer can effectively reduce fluid resistance and prevent scaling, and is suitable for high purity media (such as pharmaceutical and food industries).
Economy: By combining PTFE with high corrosion resistance and carbon steel with excellent structural properties and low cost, corrosion resistance requirements can be met, and material costs can be saved, compared with all PTFE pipes, lower cost and long maintenance cycle.

4. Application field

Due to its excellent overall performance, carbon steel PTFE lined pipe is widely used in many industries, mainly including:

Chemical Industry:
Conveying corrosive liquid or gas such as strong acid, strong alkali, solvent to ensure stable and reliable process.
Oil and Gas Industry:
When conveying sulfur-containing and acid-containing media, it protects the equipment from corrosion and improves the safety and durability of the overall system.
Power and Metallurgical Industry:
It is used to transport high temperature or corrosive media to meet the needs of high load and harsh working conditions.
Environmental and Pharmaceutical:
In some cases requiring health and safety to prevent side effects, PTFE lining can avoid metal contamination and improve product purity.

5. Use restrictions and precautions

Temperature limit: long-term use should not exceed 260°C to avoid the decomposition of PTFE.
Mechanical stress: Avoid severe temperature changes or mechanical shocks to prevent lining layer cracking.
Installation requirements: professional flange connection is required to prevent damage at the lining flanging; Avoid welding, high temperatures may damage PTFE.

Sum up

The carbon steel PTFE lined pipe optimizes the performance and economic balance through the material composite, which is the ideal choice for the transportation of corrosive media, but its design, installation and maintenance need to strictly follow the specification to ensure the service life. Medium characteristics, temperature and pressure parameters and cost factors should be considered comprehensively in the selection.