Production and Forming Process of Stainless Steel Elbows

　　When the direction of the stainless steel pipe needs to be changed during the layout process of the fixture, it needs to be connected using stainless steel elbows with angles of 45 º, 90 º, etc.

　　The commonly used method for forming stainless steel elbows is the push bending forming process.

　　Push bending is a commonly used bending method for stainless steel pipe fittings, mainly used for bending elbows. According to the characteristics of the process, it can be divided into cold push bending and core rod hot push bending.

　　1. Cold push bending

　　The process of using a bending device to push a bent pipe blank on a regular hydraulic press or crank press is to press the stainless steel straight pipe blank into a mold with a bending cavity at room temperature, thereby forming a stainless steel elbow.

　　Cold pushed elbows are suitable for stainless steel elbows with small bending radii, with a relative bending radius r/d ≈ 1.3, a small ovality of the elbow section (≤ 3% -5%), and a small thinning of the outer pipe wall (≤ 9%), which can be bent; The elbow pushing bending device has a simple structure, does not require special equipment, and has high productivity. However, the relative thickness t/d of stainless steel pipes is generally required to be ≥ 0.06. Otherwise, the pipe blank often loses stability due to poor stiffness, leading to wrinkling or twisting on the inside of the elbow.

　　2. Hot push bending of core rod

　　The core rod type hot push elbow is pushed through an ox angle core rod under axial thrust on a pushing machine, heating while pushing, causing circumferential expansion and axial bending deformation of the pipe blank, thereby pushing the smaller diameter pipe blank into a larger diameter elbow.