Standards and characteristics of carbon steel seamless elbows

Carbon steel seamless elbow is an important connector used to change the flow direction of fluid in the pipeline system. It is widely used in petroleum, chemical industry, electric power, shipbuilding and construction industries. Seamless elbows have become the first choice for pipeline systems in high-pressure, high-temperature, and corrosive environments because of their no welds, high strength, and good pressure resistance. The following are some common standard models of seamless carbon steel elbows and their characteristics.

Common standard models of carbon steel seamless elbows are:

1. ASTM A234 WPB

Application: ASTM A234 WPB is widely used in medium and low pressure piping systems.

Features: It has good welding performance and mechanical properties, and is often used in petroleum, chemical and natural gas pipelines.

2. ASTM A106 Gr.B

Application: ASTM A106 Gr.B is suitable for seamless carbon steel pipes in high temperature and high pressure environments.
Features: It has excellent high temperature performance and creep resistance, and is suitable for transporting high temperature and high pressure media.

3. ASTM A105

Application: ASTM A105 is mainly used for forged carbon steel pipe fittings in high pressure systems.
Features: High strength and good toughness, often used in high-pressure pipe fittings such as flanges and elbows.

4. ASTM A53 Gr.B

Application: ASTM A53 Gr.B is commonly used in seamless and welded carbon steel pipes, suitable for medium and low pressure environments.
Features: Economical and practical, widely used in water, gas, steam and other pipeline systems.

5. EN 10216-1 P235TR1/P235TR2

Application: Widely used in European standard pressure piping systems.
Features: It has excellent mechanical properties and welding properties, and is suitable for medium and low pressure conveying media.

6. Wall thickness standard

The wall thickness of seamless carbon steel elbows varies according to different standards and application scenarios. Common wall thickness standards include SCH (Schedule) series, such as:

SCH10: Suitable for low-pressure environments, with thin wall thickness and light weight.
SCH40: Suitable for medium pressure environments, is a common standard wall thickness with good strength and durability.
SCH80: Suitable for high-pressure environments, with thicker walls and the ability to withstand higher pressures.
SCH160: Suitable for extremely high pressure environments, with the thickest wall thickness, and suitable for the most demanding working conditions.

7. Long radius and short radius

Seamless carbon steel elbows are divided into long radius (LR) and short radius (SR) according to the bending radius:
Long radius elbow (LR): The bending radius is 1.5 times the diameter of the pipe. It has small fluid resistance and is suitable for systems with high flow rates.
Short radius elbow (SR): The bending radius is the diameter of the pipe, suitable for occasions where the installation space is limited but the fluid resistance requirements are not high.

Special material models:

ASTM A333 Gr.6
Application: ASTM A333 Gr.6 is suitable for piping systems in low temperature environments.
Features: It has good low-temperature toughness and mechanical properties, and is often used in liquefied natural gas (LNG) and low-temperature process pipelines.

ASTM A350 LF2
Application: ASTM A350 LF2 is suitable for piping systems in low temperature and high pressure environments.
Features: It has good low-temperature performance and corrosion resistance, and is widely used in manufacturing low-temperature piping systems, containers and equipment. ‌

Read more: Carbon steel tube material and use