Classifications of Steel Pipe Fittings II

② forging pipe fittings
Forged pipe fittings mainly include socket welded pipe fittings and threaded fittings; sometimes butt welded pipe fittings or pipe fittings with mixed connections are made by forging process, for example, small tees with wall thickness. Also, pipe fittings with mixed connections are sometimes made of steel pipe.

A. Socket welded pipe fittings
The standard socket welded pipe fittings include 45°elbow, 90°elbow, tee, cross, 45°lateral tee, double socket pipe hoop, single socket pipe hoop, cap, union, and so on. Among which, tees and crosses are classified into equal and reducing; double socket pipe hoop also have equal and reducing types, reducing double socket pipe hoops can be classified into concentric and eccentric.
 
Standards and classifications of pipe fittings  
 Name  Type
elbow 45°  
90°  
 tee  equal 
 reducing 
45° lateral tee  equal 
 reducing 
cross
 
 equal 
 reducing 
 double socket pipe hoop  equal 
 reducing  concentric
 eccentric
 single socket pipe hoop   
 cap   
 union   

B. Threaded pipe fittings
Threaded pipe fittings include 45°elbow, 90°elbow, tee, cross, double-ended coupling, single-ended coupling, cap, plug, internal and external threaded union, etc. Tees and cross can be classified into equal tees and reducing tees, which is the same as the socket welded pipe fitting; double-ended couplings can also be classified into equal double-ended couplings and reducing double-ended couplings, and reducing double-ended couplings include concentric and eccentric; there are square head, hexagonal head and round head for pipe plugs; internal and external threaded union has hexagonal and headless types.
 
Regular threaded pipe fittings
Name Type
 elbow 45°   
90°   
 tee equal  
 reducing  
 cross equal  
reducing  
 coupling double-ended  concentric
 eccentric
 single-ended  
 plug  square head  
 hexagonal head  
 round head  
Internal & external threaded union  hexagonal head  
 headless  
union    
cap    

C. Pipe fittings with mixed connections
Pipe fittings with mixed connections contains tees, crosses, elbows, couplings with socket welded and threaded, as well as reducing pipes which are connected by butt welding, socket welding or threaded welding. This type of pipe fitting can be processed based on the requirements of different connections.