What are the differences between DN125 seamless steel pipe and internally coated steel pipe

First, what is DN125 seamless steel pipe?
1) Basic concept: DN125 seamless steel pipe is a type of seamless steel pipe with a specific diameter (DN125, corresponding to an outer diameter of approximately 140mm). Seamless steel pipes are made by piercing solid tube blanks or steel ingots and then processing them through hot rolling, cold rolling, or cold drawing. Because it has no weld seams, it can withstand higher pressure and is typically used in high-pressure and high-temperature environments.
2) Material and wall thickness: Seamless steel pipes are usually made of high-quality steel such as 20#. The wall thickness varies depending on the specific application requirements, but it generally meets various pressure requirements.
3) Application scenarios: Due to its high strength, corrosion resistance, and high-temperature resistance, DN125 seamless steel pipe is widely used in fire protection systems, construction engineering, machining, machinery manufacturing, cable protection, decoration, chemical industry, and building construction, among other fields. Especially in fire protection systems, DN125 seamless steel pipes are often used as water supply pipelines, such as fire hydrant systems, sprinkler systems, and automatic sprinkler systems.

Secondly, what is DN125 internally coated seamless steel pipe?
1) Basic concept: DN125 internally coated seamless steel pipe is a composite pipe formed by coating a layer of plastic material (such as epoxy resin, polyethylene, etc.) onto the inner wall of a DN125 seamless steel pipe through a hot-dip plastic coating process.
2) Coating characteristics: The internal plastic coating layer has excellent insulation, high strength, corrosion resistance, high temperature resistance, wear resistance, and tensile strength. The coating has a strong adhesion to the pipe material, with an adhesion strength of 50-70 kg per square centimeter, and the adhesion strength does not decrease during long-term use. At the same time, the coating thickness is uniform, and the corrosion resistance far exceeds that of similar domestic products.
3) Application Scenarios: Due to its unique coating characteristics, DN125 internally coated seamless steel pipes are widely used in power system renovation projects, water supply and drainage systems, fire protection systems, and other piping systems requiring corrosion resistance, insulation, and wear resistance. Especially in power engineering, it is often used as a cable conduit to protect cables from external environmental corrosion.

Thirdly, what are the prices and purchasing suggestions for DN125 seamless steel pipes?
1) Price Factors: The price of DN125 seamless steel pipes and internally coated seamless steel pipes is affected by multiple factors such as production costs, raw material prices, market demand, brand, and quality. Therefore, the choice should be made based on actual needs and budget.
2) Purchasing Suggestions:
Choose well-known brands: Products from well-known brands offer more guaranteed quality and more comprehensive after-sales service.
Pay attention to product certifications: Ensure that the product meets relevant standards and certification requirements, such as ISO certification and fire protection product certification.
Understand product performance: Before purchasing, understand the key indicators of the product, such as material, wall thickness, and corrosion resistance.
Compare price and quality: When purchasing, consider not only price but also product quality and service.

In conclusion, DN125 seamless steel pipes and their internally coated varieties have attracted much attention due to their unique properties and wide range of applications. When purchasing, it is necessary to select based on actual needs and budget, and pay attention to aspects such as brand, certification, performance, and quality.