N.Y. Comp. Codes R. & Regs. tit. 16, § 255.145
(b) Each cast iron and plastic valve must comply with the following:
(2) The valve must be tested as part of the manufacturing, as follows:
(d) No valve having shell (body, bonnet, cover, and/or end flange) components made of ductile iron may be used at pressures exceeding 80 percent of the pressure ratings for comparable steel valves at their listed temperature. However, a valve having shell components made of ductile iron may be used at pressures up to 80 percent of the pressure ratings for comparable steel valves at their listed temperature, if: