1. By material type:

Carbon Steel: ASTM/ASME A234 WPB, WPC

Alloys: ASTM/ASME A234 WP 1-WP 12-WP 11-WP 22-WP 5-WP 91-WP911, 15Mo3, 15CrMoV, 35CrMoV

Stainless Steel: ASTM/ASME A403 WP 304-304L-304H-304LN-304N

ASTM/ASME A403 WP 316-316L-316H-316LN-316N-316Ti

ASTM/ASME A403 WP 321-321H ASTM/ASME A403 WP 347-347H

Low-Temperature Steel: ASTM/ASME A402 WPL3-WPL6

High-performance Steel: ASTM/ASME A860 WPHY 42-46-52-60-65-70

Cast steel, alloy steel, stainless steel, copper, aluminum alloys, plastic, asbestosis, PVC, PPR, RFPP (reinforced polypropylene), etc.

Aluminum alloy 3003, 6061, copper, brass, bronze

2. Divided by manufacturing methods, it can be categorized into extrusion, pressing, forging, casting, etc.

3. Classified by manufacturing standards, it can be divided into national standards, electrical standards, marine standards, chemical standards, water standards, American standards, German standards, Japanese standards, Russian standards, and more.

4. Categorized by their radius of curvature: They can be divided into long-radius elbows and short-radius elbows. Long-radius elbows refer to elbows where the radius of curvature is 1.5 times the outer diameter of the pipe, i.e., R=1.5D; short-radius elbows refer to elbows where the radius of curvature is equal to the outer diameter of the pipe, i.e., R=1.0D. (D is the elbow diameter, R is the radius of curvature.)