The Commonly Used Pipe Fittings

Crosses
Crosses are pipe fittings or connecting parts for pipes. Crosses are used at the pipes where fluid of the main pipeline needs to be diverted. Pipe crosses include equal crosses and reducing crosses. The four ends of equal crosses have the same diameters; reducing crosses' two pipe ends which are connected to main pipelines have the same diameters; the other two ends are connected to branch pipes, and their sizes are smaller than the main pipelines'.

Gaskets
Gaskets are placed between two surfaces to improve sealing performance and prevent fluid leakages.
 
Bends
Bends are made by a set of bending molds. No matter what kind of machine equipment or pipes, bends can be applied to most of them. Bends are mainly used for transporting oil, gas, fluid, etc., and they can be classified into pressing bends,  forging bends, casting bends, etc. based on manufacturing methods. 

Valves
Valves are control parts in fluid delivery systems, which have functions of cut-off, regulation, diversion, overflow, pressure relief, etc. Pipe fittings include welded pipe fittings, threaded pipe fittings, socket pipe fittings, etc. according to connection modes. 

Welded Pipe Fittings
Welded pipe fittings are pipe fittings which are connected to pipes by welding. Welded pipe fittings include elbows, flange plates, tees and reducers, and they are often used for steel pipes, non-ferrous metal pipes, PVC pipes, etc. Welding pipe fittings are especially suitable for long pipelines, but they are not suitable for pipelines which are often disassembled. Welding pipe fittings can be fusion welded or braze welded, and braze welded is often applied to copper pipes.

Threaded Pipe Fittings
Threaded pipe fittings are pipe fittings with threads, which are mainly used for water & gas pipes, water pipes with small diameters, compressed air pipes, low pressure steam pipes, etc.

Connection Methods
Connection methods of socket pipe fittings series include socket welded connections(SW), butt welded connections(BW) and threaded connections.

Application Fields
Socket pipe fittings are mainly applied to sectors and fields such as petrochemistry, health & medicine , electricity, aerospace, military, fire fighting, metallurgy, shipbuilding, gas, nuclear power, environmental protection, etc., which require high pressure and dimensional accuracy.

Pipe fittings include cast steel pipe fittings, cast iron pipe fittings, stainless steel pipe fittings, graphite pipe fittings, forged steel pipe fittings, alloy pipe fittings according to materials.

Conclusions
Pipelines are everywhere in our daily life. Pipe fittings as components of pipelines, although every pipe fitting seems to be light, actually it has great significance and is closely related to our lives. Therefore, it is also very necessary to learn basic knowledge of these pipe fittings. I believe that you will have a certain understanding of pipe fittings' materials, uses, connection modes, etc. after reading this article.