chapter  18
28 Pages

- S

Pipes are specified by their nominal bore (NB), nominal pipe size (NPS) for sizes up to 12″ (304.8 mm) and by their od for higher sizes. Thickness is specified by the schedule, which is a number indicating the approximate value of

Sch. = 1000 P/S, where P = service pressure (psi), S = allowable stress (psi).