Reduced Bend Fitting

Welded Elbow Introduction

Welded elbow alias: Pressed elbow, Seamless elbow, Steel elbow, Forged elbow, Weld neck elbow, etc., different regions have different names, all belonging to a type of elbow series.

Welding elbows are metallic pipe fittings used to change the direction of pipeline on a pipe.

Application: Connect two pipes to change the direction of the pipes to 45 degrees, 180 degrees, 90 degrees, or other angles for bends.

Manufacturing Standards: National Standard, American Standard, Japanese Standard, German Standard, Russian Standard

Variety Classification

Welded elbow curvature radii: They can be divided into long-radius elbows and short-radius elbows. A long-radius elbow refers to one where the curvature radius is 1.5 times the pipe's outer diameter, i.e., R = 1.5D. A short-radius elbow refers to one where the curvature radius is equal to the pipe's outer diameter, i.e., R = 1.0D; (D represents the elbow diameter, and R represents the curvature radius; D can also be expressed as a multiple.)

Welded elbows are categorized by angle: The three most commonly used are 45-degree elbows, 90-degree elbows, and 180-degree elbows. Additionally, other non-standard angle elbows, such as 60-degree elbows, are included according to engineering requirements.

Welded elbows are categorized by material: carbon steel elbows, stainless steel elbows, alloy steel elbows, etc.

Welded elbows are categorized by pressure class, with approximately seventeen types. Those that are identical to U.S. pipe standards include: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, Sch100, Sch120, Sch140, Sch160, XXS. The most commonly used types are STD and XS.

Production Process

Welded elbows can be broadly categorized into: hot-formed, stamp-formed, and mid-plate welded-formed.

The hot push bending process is highly recommended for its aesthetically pleasing shape, uniform wall thickness, and continuous operation, making it suitable for mass production. As a result, it has become the primary forming method for carbon steel and alloy steel elbows, and is also used in the forming of certain specifications of stainless steel elbows.

Bent pipe formed by stamping was an earlier technique used for mass production of seamless bends, but has been replaced by hot pushing or other forming methods for commonly used specifications. However, it is still used for certain sizes of bends due to low production volumes, excessively thick or thin walls.

A half-section of the elbow profile is formed using a medium plate on a press brake, and then the two sections are welded together; this process is generally used for the production of large-diameter socket-welded elbows with DN700 and above.

Application Fields

Welded elbows are widely used in fundamental projects such as chemicals, construction, water supply and drainage, oil industry, light and heavy industries, refrigeration, sanitation, plumbing, fire protection, power, aerospace, and shipbuilding, due to their excellent comprehensive performance.

Procurement Recommendations

1: Recommend purchasing from a reputable elbow manufacturer with a certain production scale.

2: manufacturers of elbows must provide material inspection reports and relevant documents.

3: Elbows must have corresponding specification model stamping and marking.