Carbon, Alloy and Stainless Steel Pipes - ASME/ANSI B36.10/19 
http://www.engineeringtoolbox.com/steel-pipes-dimensions-d_43.html

Copper Tubes - Copper Water and Gas Tube according ASTM B 88  
http://www.engineeringtoolbox.com/astm-copper-tubes-d_779.html

PVC and CPVC Pipes - Schedule 40 & 80
http://www.engineeringtoolbox.com/pvc-cpvc-pipes-dimensions-d_795.html

Difference between Pipes and Tubes
http://www.engineeringtoolbox.com/pipes-tubes-d_347.html

Piping system - general information 
http://www.engineeringtoolbox.com/piping-tubing-systems-t_6.html
http://www.engineeringtoolbox.com/nps-nominal-pipe-sizes-d_45.html