Straight Couplings

• Straight copper couplings join one pipe section to another, with the pipes forming a straight line. The couplings come in 1/2- and 3/4-inch diameters to fit copper pipes. Each coupling is roughly 2 inches long, with a central inner lip so that the pipes enter the coupling's ends but travel no farther than halfway into the coupling.
  
  

Angled Couplings

• Where copper lines need to travel around pre-existing objects such as joists and sewer pipes, use angled couplings. These allow for a change of gradient, or water supply, to different levels of the house. The couplings come in 30, 45, 60 and 90 degrees.
  
  

Tee Couplings

• Shaped like a letter T, a tee coupling joins two copper pipelines together. One pipeline is cut and the tee's opposite inlets squeezed between the pipe cuts, and its leg then connects to another line. The tee's leg is at a 90-degree angle to the coupling body.
  
  

End Cap

• Use a copper end cap to seal an existing pipe, either temporarily or permanently. The end cap looks like a shortened version of straight coupling, but with one end sealed off. Later, if desired, the cap is easily cut out of place and a new section of pipe joined to the existing pipe.