Pipe Size

See table of standard pipe sizes up to XXH:

• http://www.engineersedge.com/pipe_schedules.htm

OD and ID

• http://www.engineeringtoolbox.com/ansi-steel-pipes-d_305.html. 1" schedule 40 may fit inside 1-1/4" schedule 40.
• 2" schedule 80 fits around 1-7/8" shaft - it is 1.939 ID, or 0.06 slop

Pipe PSI

https://www.engineeringtoolbox.com/wrought-steel-pipe-bursting-pressure-d_1123.html