46 CFR § 56.60-15 - Ductile iron.
(a) Ductile cast iron components made of material conforming to ASTM A 395 (incorporated by reference, see 46 CFR 56.01–2) may be used within the service restrictions and pressure-temperature limitations of UCD–3 of section VIII of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR 56.01–2).
(b) Ductile iron castings conforming to ASTM A 395 (incorporated by reference, see § 56.01–2) may be used in hydraulic systems at pressures in excess of 7500 kilopascals (1000 pounds per square inch) gage, provided the following:
(1) The castings receive a ferritizing anneal when the as-cast thickness does not exceed one inch;
(2) Large castings for components, such as hydraulic cylinders, are examined as specified for a casting quality factor of 90 percent in accordance with UG–24 of section VIII of the ASME Boiler and Pressure Vessel Code; and
(3) The castings are not welded, brazed, plugged, or otherwise repaired.
(c) After machining, ductile iron castings must be hydrostatically tested to twice their maximum allowable working pressure and must show no leaks.
(d) Ductile iron castings exhibiting less than 12 percent elongation in 50 millimeters (2 inches) when subjected to a tensile test must meet the requirements for cast iron in this part.