Seamless Carbon Steel Bend Order

Our regular customer in Singapore needs to purchase a batch of seamless carbon steel bend with a material of API 5L B CL2, radius of 750mm, angles of 90 degrees and 45 degrees, and dimensions of DN200 SCH40. After receiving this order, we relied on our accurate understanding of customer needs and professional service capabilities to quickly advance order fulfillment, from parameter confirmation to detail optimization, ensuring timely delivery of the order.

Purchase Details

From the procurement list, it can be seen that the batch of seamless carbon steel bend purchased by the customer is suitable for harsh environments, so the quality requirements for the bent pipes are relatively strict.

Material: API 5L B CL2, this material belongs to high-quality carbon steel, with excellent tensile strength (≥ 415MPa) and yield strength (≥ 245MPa), suitable for the pressure and medium transportation needs of customer pipeline systems, and is a reliable material commonly used in the fields of petroleum, natural gas, etc;

Dimension: DN200 (219.1mm), SCH40 (8.18mm), which can match the diameter and pressure design of the customer's existing pipelines, ensuring the sealing and structural stability of pipeline connections;

Radius: The radius is 750mm, and the bending angle covers 90 degrees and 45 degrees. The two angles can meet the layout requirements of customers' pipeline systems in different directions, avoiding local pressure concentration problems caused by unsuitable angles in the pipeline;

Surface requirements: The customer has explicitly stated that painting is not necessary. Although this requirement simplifies the surface treatment process, it also puts higher demands on product rust prevention. To ensure the surface quality of the bent pipe, we have specially arranged surface sandblasting treatment before packaging. Design multi-layer packaging solutions in terms of packaging, balancing sealing and impact resistance to ensure the safety of goods during transportation.

What is Seamless Carbon Steel Bend

Seamless carbon steel bend refers to the use of carbon steel material, with a bending radius of more than 3 times the outer diameter of the port (R>3D). Made through specific processing techniques, it can effectively change the direction of pipelines and meet the requirements of complex pipeline design.

The advantages of seamless carbon steel bend stem from the carbon steel material itself. ASTM A234 WPB, A106B, API 5L and other representative materials of seamless carbon steel bending pipes have superior performance, good strength and hardness, can withstand high pressure, and operate stably in various industrial environments; At the same time, carbon steel material has good toughness, is not easily damaged by external impact, and has relatively low cost and high cost-effectiveness, saving costs for pipeline engineering.

Chemical Composition

Mechanical Properties

High strength pressure resistance: Carbon steel has a moderate carbon content and forms a tight metal crystal structure, which can withstand a working pressure of 60MPa. In high-pressure transportation scenarios (such as oil field pipelines), it can resist medium impact and avoid pipeline deformation and rupture;

High toughness and impact resistance: Through quenching and tempering treatment, the impact toughness of carbon steel reaches 27J/cm ² or above. Even in low-temperature environments (-20 ℃ to 0 ℃) or external force collisions, it is not prone to brittle fracture and is suitable for complex outdoor installation environments;

High cost-effectiveness: Compared to stainless steel materials, carbon steel has a 30% -50% lower raw material cost and is less difficult to process. It does not require complex anti-corrosion coating pretreatment and can significantly reduce the total project cost in non corrosive media (such as water and steam) transportation.

Types of Carbon Steel Bend

The most common types are 45 degree, 90 degree, and 180 degree bends. In addition, carbon steel bend pipes are classified according to process and appearance, including seamless and straight seam bend pipes; There are various types of bends, such as J-shaped bends, angled bends, U-shaped bends, etc.

Seamless carbon steel bend refers to a bend pipe that does not produce welding seams during the manufacturing process. It is made by bending seamless steel pipes, with a complete overall structure and no weak links in the welding seams. It can avoid the risk of leakage caused by welding seam problems and improve the safety of the pipeline system.

Welded bend is made by splicing and bending steel plates or pipes through welding process, with obvious weld seams. Compared with seamless bend, welded bends are slightly inferior in strength and sealing. Straight seam bend pipe is a type of welded bend pipe, with a straight weld seam.

In terms of pressure bearing capacity, seamless carbon steel bends have no welds, resulting in more uniform pressure bearing and the ability to withstand higher pressures; The weld seam of straight seam bent pipes is prone to become a weak point, limiting their pressure bearing capacity.

In terms of sealing, seamless bent pipes are seamless as a whole, with better sealing performance and reduced leakage hazards; If the weld seam of the bent pipe is not handled properly, it is prone to sealing problems.

In terms of service life, seamless bent pipes have better corrosion resistance and fatigue resistance, and a longer service life; The weld seam of the bent pipe is susceptible to corrosion, which affects its service life.

The Difference Between API5L GRB CL1 and CL2

In the procurement and production of seamless carbon steel pipes and fittings (such as bend), API 5L GRB (Grade B) with CL1 (Class 1) and CL2 (Class 2) are two common grades. Although both belong to the API 5L GRB material system, there are clear differences in mechanical properties, applicable scenarios, inspection requirements, etc., which need to be selected based on actual situations.

Mechanical properties

Mechanical properties are the core indicators that distinguish between CL1 and CL2, directly determining the pressure bearing capacity and risk resistance of pipe fittings. Specific parameters must comply with the requirements of API 5L standard:

Taking the API 5L B CL2 bend pipe in Singapore customer orders as an example, it is precisely because it requires a mandatory impact toughness of ≥ 27J at 0 ℃ to adapt to possible low-temperature storage or transportation environments, and CL1 cannot meet the safety requirements of such scenarios.

Application

The difference in applicable scenarios between the two is essentially determined by the different mechanical properties (especially impact toughness), which need to be comprehensively judged based on factors such as medium temperature, pressure fluctuations, and environmental conditions

API 5L GRB CL1

Temperature range: Suitable for normal temperature environment (-10 ℃ to 50 ℃), without low temperature or severe temperature fluctuations;

Medium type: Suitable for low-pressure, non impact ordinary media, such as room temperature clean water, low-pressure air, non corrosive crude oil (sulfur free or low sulfur);

Application scenarios: mostly used in urban water supply and drainage pipelines, low-pressure heating pipelines, industrial circulation water pipelines with low temperature and pressure, and other scenarios that do not require high toughness;

Typical case: The DN150 SCH40 bend pipe for the ambient temperature circulating water pipeline in a certain park can meet the requirements of 0.8MPa working pressure and 25 ℃ ambient temperature by using CL1, with lower cost.

API 5L GRB CL2

Temperature range: Suitable for low-temperature environments (-20 ℃ to 0 ℃) or scenarios with large temperature fluctuations (such as intermittent steam transportation);

Medium type: Suitable for high-pressure (≤ 6MPa) and medium with slight impact, such as low-temperature liquefied natural gas (LNG) transportation, sulfur-containing crude oil, high-pressure steam, etc;

Application scenarios: long-distance oil and gas pipelines, chemical low-temperature reaction pipelines, high-pressure oil pipelines in coastal areas (with lower temperatures), etc;

The core difference between API 5L GRB CL1 and CL2 lies in their low-temperature impact toughness, inspection rigor, and applicable scenarios. It is not simply a matter of "high or low grade", but rather "on-demand matching".

Inspection and Packaging of Seamless Carbon Steel Bend

The inspection process is crucial to ensure the quality of seamless carbon steel bend. Before leaving the factory, we will measure its dimensions and check whether the pipe diameter, wall thickness, bending angle, etc. meet the standards; Conduct a visual inspection to check for surface defects such as cracks, dents, rust, etc; We will also conduct pressure tests to verify its pressure bearing capacity and sealing performance, and only products that are fully qualified can be shipped.

On the packaging, wooden boxes, woven bags, and other packaging methods will be used according to product specifications and transportation needs to prevent collisions and wear during transportation, ensuring that the products are delivered to customers intact and undamaged.