Elbow is a pipe fitting that changes the direction of the pipe in the piping system. According to the angle, there are three most commonly used 45° and 90°180°, and other abnormal angle elbows such as 60° are also included according to engineering needs.
Elbows are made of cast iron, stainless steel, alloy steel, malleable iron, carbon steel, non-ferrous metals and plastics.
The difference between the stainless steel elbow and the carbon steel elbow is mainly due to the difference in material. The chemical composition of the elbow will keep the surface of the elbow from rusting for a long time and will not be corroded.
Classification
Divided by material
Carbon steel:
Alloy:
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-WPL 6
High performance steel:
ASTM/ASME A860 WPHY 42-46-52-60-65-70
Cast steel, alloy steel, stainless steel, copper, aluminum alloy, plastic, argon leaching, PVC, PPR, RFPP (reinforced polypropylene).
Divided by production method
Push, press, forge, casting, etc.
Divided by manufacturing standards
National standard, electric standard, ship standard, chemical standard, water standard, American standard, German standard, Japanese standard, Russian standard, etc.
According to the radius of curvature
Can be divided into long radius elbows and short radius elbows.
A long radius elbow refers to the outer diameter of a tube whose radius of curvature is equal to 1.5 times, that is, R = 1.5D;
A short radius elbow refers to a radius of curvature equal to the outer diameter of the tube, that is, R = 1.0D. (D is the elbow diameter and R is the radius of curvature).
According to the pressure level
There are about seventeen types, which are the same as the American pipe standards: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, SCH100, Sch120, Sch140, Sch160, XXS ;
The most commonly used ones are STD and XS.
According to the shape use can be divided:
Grooved elbow, ferrule elbow, double bearing elbow, flange elbow, reducer elbow, dull elbow, inner and outer elbow, punch elbow, push elbow, socket elbow , butt weld elbow, inner wire elbow, etc.
General classification
Flexible elbow、 ferrule elbow、 belt elbow、 quick elbow、 seat elbow、 flange elbow、 180° elbow、 double bearing elbow、 single bearing elbow、 socket bending Head、 reducer elbow、seamless elbow、 butt weld elbow、90° elbow、45° elbow、 combined tee internal thread elbow、stamping elbow、push elbow、high pressure elbow wear-resistant bend Head、mechanical elbow、flanged elbow、grooved elbow, three-dimensional elbow external thread elbow、 thread elbow、special elbow、waterproof elbow.
Scope of use
Because the elbow has good comprehensive performance, it is widely used in chemical engineering, construction, water supply, drainage, petroleum, light and heavy industry, refrigeration, sanitation, plumbing, fire protection, electric power, aerospace, shipbuilding and other basic projects.
