What is Smls in piping?

What is Smls in piping?

SMLS is the abbreviation of "Seamless". In the field of pipelines, it specifically refers to seamless steel pipes, that is, weld-free metal pipes produced by hot rolling, cold rolling or extrusion. Smls pipes are manufactured by special processes and have the characteristics of no welds, high strength and wide applicability. They are often used in high-pressure, high-temperature or high-precision scenarios.

The core features of SMLS pipes:

1. No welds
The overall structure of seamless pipes is continuous during production, avoiding strength weaknesses and leakage risks caused by welds.

2. High pressure bearing capacity
Due to the seamless design, its structure is tighter, so it has better strength and pressure resistance. The bursting pressure is 30%~50% higher than that of welded pipes of the same specification.

3. Pure materials
No welding impurities, suitable for high-purity medium transportation (such as semiconductor ultrapure water, pharmaceutical gases).

4. Corrosion resistance
If the seamless steel pipe is made of carbon steel, it is easy to rust and needs to be galvanized or coated. It can be replaced with stainless steel, which can resist the erosion of most acids, alkalis, salts and other chemical substances, and is suitable for a variety of corrosive environments.

5. Processing flexibility: heat treatment (normalizing, quenching), cold bending (bending radius ≥ 3 times the outer diameter).
6. Wide range of applications: SMLS pipes are widely used in many fields such as petroleum, chemical industry, electricity, water conservancy, and construction due to their excellent performance.

SMLS pipe manufacturing process:
The production of seamless steel pipes mainly adopts hot rolling or cold drawing technology. Taking the hot rolling process as an example, the steel billet is heated to a high temperature and then pierced, and then continuously rolled into shape by rollers. The cold drawing process stretches the steel pipe at room temperature to improve the surface finish and dimensional accuracy. Both processes do not require welding steps, avoiding structural defects that may be caused by welds, thereby ensuring the overall uniformity of the material.

Application scenarios of SMLS pipe:

1. Energy transportation field: SMLS steel pipes are often used in oil and natural gas pipelines because they can withstand high pressure environments and have excellent corrosion resistance.
2. Mechanical manufacturing industry: Precision parts such as hydraulic cylinders and bearing sleeves rely on the dimensional stability and mechanical strength of seamless steel pipes.
3. Automobile and aviation fields: Key parts such as drive shafts and landing gear use their lightweight and fatigue resistance.
4. Chemical equipment: In the manufacture of reactors and heat exchangers, seamless steel pipes can withstand high temperatures and chemical media erosion.

Advantages compared to traditional steel pipes:

1. Structural integrity: The weld-free design eliminates weak links, and the compressive strength is increased by more than 30% compared to welded steel pipes.
2. High safety factor: Suitable for extreme working conditions, such as deep-sea oil and gas extraction or supercritical thermal power generation units.
3. Long service life: The uniform metal streamline structure significantly enhances the resistance to stress corrosion.
4. Processing adaptability: The mechanical properties can be adjusted through heat treatment to meet the special needs of different industries for hardness and toughness.

At present, a complete standard system has been formed for SMLS steel pipes, including international general specifications such as ASTM A106 (high temperature service) and API 5L (line pipe), which further promotes its popularization and application in the global industrial field.

Read more: Seamless Steel Pipe Sizes and Weights or Seamless Thick Wall Steel Pipe