Carbon steel high-pressure butt welding flange

Carbon steel high-pressure butt welding flange

Executive standard: GB/T13402-2010

Specification size: 26

Pressure rating: Class300~Class900

Connection form: neck welding, single-sided bolt fastening

Brief introduction of high-pressure butt welding flange

High-pressure butt-welding flanges generally refer to butt-welding flanges or flanges that can withstand a relatively high-pressure level, because only neck-welding flanges can be applied to high-pressure pipelines or flammable and explosive On dangerous pipelines because the butt welding of the neck and the pipeline can be inspected by radiographs, the pipeline will not leak.

Carbon steel high-pressure butt welding flange

Features of high-pressure butt welding flange

The butt welding flange is not easy to deform, has good sealing, and is widely used. It has corresponding rigidity and elasticity requirements and a reasonable butt welding thinning transition. The distance between the welding port and the joint surface is large, and the joint surface is free from deformation due to welding temperature.

Due to its design characteristics and the diversity of sealing surfaces, it is generally used in pipelines with relatively high-pressure levels or inflammable and explosive pipelines.

Specifications

26″~60″

Pressure Level

Class300~Class900

Sealing surface type

Raised face (RF), full face (FF), concave-convex face (MFM), concave face (FM), convex face (M), tongue and groove face (TG);

Among them, the concave-convex neck butt welding flange (MFM) belongs to supporting use;

High-pressure flanges have more convex or concave-convex surfaces and tongue-and-groove surfaces. Due to the principle of their sealing surfaces, they can withstand higher pressures.

Carbon steel high-pressure flange

High-pressure butt welding flange material

ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70;

Among them, the commonly used materials are Q235, 20# and 16Mn.

Executive standard

National standards, standards of the Ministry of Chemical Industry, standards of the Ministry of Machinery, American Standards, German Standards, Japanese Standards and other national standards are widely used;

Connection Type

The welding seam connecting the neck butt welding flange and the connecting pipe belongs to the B-type seam, and the welding seam is in the form of a circular butt welding seam. After the neck welding is completed, the bolts can be tightened.

Production Process

High-pressure flanges must be forged with pure materials to increase the density of the flanges, thereby achieving the greater performance of the butt-welding flanges;

1. The basic process of die forging process: blanking, heating, pre-forging, final forging, punching and skinning, trimming, quenching and tempering and shot peening. Common processes include upsetting, drawing, bending, punching and forming.

2. Commonly used die forging equipment includes die forging hammers, hot die forging presses, flat forging machines and friction presses.

In layman’s terms, forged flanges are better in quality, generally produced by die forging, have a fine crystal structure and high strength, and of course, are more expensive.

High-pressure butt welding flange

Advantages of high-pressure butt welding flange

Due to its good sealing performance, the carbon steel neck butt welding flange is suitable for high-pressure pipelines and flammable and explosive projects;

The neck butt welding flange is not easily deformed in the welding process;

Purchasing advice

1: The flange manufacturer needs to provide relevant information such as the material inspection report of the welded neck flange;

2: Welding neck flanges need to have corresponding specifications and models stamped and marked;