13 NCAC 13 .0504 FACTORS OF SAFETY
(a) For nonstandard boilers, the factor of safety is four and one‑half, except for horizontal‑return tubular boilers having continuous longitudinal lap seams more than twelve feet in length, where the factor of safety is eight. When this latter type of boiler is removed from its existing setting, it shall not be reinstalled for pressure in excess of fifteen psig.
(b) The factor of safety for nonstandard boilers with lap‑riveted longitudinal seams less than twelve feet in length is six.
(c) The factor of safety for a nonstandard boiler with butt and double‑strapped longitudinal seams is five.
(d) For nonstandard pressure vessels, the factor of safety is four, except that for non‑ASME Code constructed hydropneumatic storage tanks containing water under pressure at ambient temperatures the factor of safety is two.
History Note: Filed as a Temporary Amendment [(e)! Eff. March 10, 1982, for a Period of 120 Days to
Expire on July 8, 1982;
Statutory Authority G.S. 95‑69.11; 95‑69.14;
Eff. May 29, 1981;
Amended Eff. June 1, 1982;
Readopted [(e) Eff. January 1, 1986];
Amended Eff. January 1, 1995.