Is there any kind of standard dealing with an underground conduit system? Anything pertaining to sweeps versus 90's and a total number of how many degree's of bend you are allowed.
Thre is no NEC article that states sweepable over 90.
What type of conduit?
344.24 is minimum radius of conduit bends
NEC does limit the number of bends to (4) quarter bends (360degrees) between pull points.
What is going in the conduit?
There are minimum bending radii for communications cables.
Standard or Code?
Telecommunications standards typically limit the amount of bends to 180 degrees in a run. BICSI has an Outside Cabling Plant Handbook that is outstanding.