Stamped Elbow

Stamped elbow is a pipe fitting formed through stamping process, mainly used to change the direction of pipelines. Due to high production efficiency and low cost, it is widely used in medium and low pressure, room temperature pipeline systems. Here is a detailed introduction:

1、 Core Features: Advantages and Limitations of Stamping Technology

The forming principle of stamped elbows is to make steel plates or steel pipe blanks by stamping, bending and welding (or seamless stamping) through molds, and its core characteristics are determined by the process:

High production efficiency: Batch stamping of molds is suitable for large-scale standardized production, and a large number of products of the same specifications can be manufactured in a short period of time.

Low cost: Raw materials (mostly ordinary carbon steel) and processing costs are lower than forging, hot pressing and other processes, with outstanding cost-effectiveness.

Wide size range: can produce products from small caliber (such as DN15) to medium caliber (within DN600), and special molds can be customized to larger specifications.

Limitations: The overall strength is slightly lower than that of seamless or forged elbows, and the pressure and temperature resistance are limited. It is usually suitable for working conditions with a pressure of ≤ 1.6MPa and a temperature of ≤ 200 ℃.

2、 Classification: Divided by molding method and structure

Divided by molding process

Welding stamping elbow: The most common type is to first punch the steel plate into two semi-circular or fan-shaped blanks, bend them and weld them at angles of 90 °, 45 °, etc. The weld seam is usually located on the back or side of the elbow.

Seamless stamping elbow: It is formed by direct stamping of steel pipe blanks, without welds, and has better strength than welded types. However, it requires higher requirements for blanks and molds, and the cost is slightly higher.

Divided by angle

Conventional angles: 90 ° (most commonly used), 45 °, 180 ° (U-bend), special angles (such as 30 °, 60 °) can be produced through customized molds.

Divided by curvature radius

Long radius (LR, R=1.5D): Low fluid resistance, suitable for most pipelines;

Short radius (SR, R=1.0D): saves space and is used in scenarios with compact pipeline layouts.

3、 Common materials

Stamping elbows are mainly made of low-cost materials, matching low pressure and room temperature application scenarios:

Ordinary carbon steel: such as Q235 and 20 # steel, suitable for non corrosive room temperature media such as water, air, and gas.

Low alloy steel: such as Q345 (16Mn), with slightly higher strength than carbon steel, can be used for medium and low pressure heating and air conditioning pipelines.

Stainless steel: such as 304 and 316, made by stamping and welding, with certain corrosion resistance, used in mildly corrosive environments (such as tap water, weak acid and alkali pipelines), but stamping may damage the passivation film on the surface of stainless steel, requiring secondary treatment (such as polishing).

4、 Production process flow

The manufacturing steps of stamped elbows are simple and efficient, and the typical process is as follows:

Raw material preparation: Cut steel plates (welded type) or select steel pipe blanks of corresponding diameters (seamless type) according to the specifications of the elbow.

Stamping forming: Heat the billet (or at room temperature) and place it in a dedicated mold. Use a hydraulic press to press and bend the billet to form an angle and curvature that conforms to the mold.

Welding and trimming: Welded elbows need to be welded at the interface, and the weld seam should be polished after removing welding slag; Seamless type directly adjusts the port size.

Surface treatment: rust removal, painting (carbon steel) or polishing (stainless steel) to prevent oxidation and corrosion.

Inspection: Check the dimensions (angle, diameter, wall thickness), weld quality (no cracks, pores), and pressure resistance (hydrostatic test).

5、 Application Fields

Stamped elbows are mainly used in scenarios where strength and weather resistance are not required due to their high cost-effectiveness

Building water supply and drainage: Cold and hot water pipelines for civil or industrial buildings, such as residential water supply and air conditioning water circulation systems.

Heating and ventilation: the turning point of radiator connecting pipes and air conditioning ducts.

Low pressure industrial pipelines: pipelines that transport inert media such as ambient temperature air, nitrogen, and low-pressure water, such as compressed air pipelines in factory workshops.

Municipal engineering: urban sewage pipe network, rainwater discharge pipeline (mostly large-diameter welded and stamped elbows).