Material specifications for nodular iron are given in Section 2-3-10 of the ABS Rules for Materials and Welding (Part 2). Nodular iron is not permitted for the construction of valves and fittings for temperatures of 350°C (662°F) and above. Nodular iron may be used for Classes I and II piping systems and for valves listed in 4-6-2/3.1.3 provided it has an elongation of not less than 12% in 50 mm (2 in.).