This is dependent on
1. Piping Code you take
2. Operating temperature
3. Medium in your Pipe (corrosion)
4. $ /kg cost material

Khaja,

there is a page full of posts from more than four years listed when using the 'Search' tab for "ductile iron" in the CAESARII forum . others have learned to analyze ductile iron. you can learn too. first go through the design differences of dimensions for ductile iron pipe, fittings, and the flanged connections that result in much more weight. that will help you in starting the model.

Thank you Mr. Richard for your Suggetion

I have to integrate DI (ductile iron) piping with our FRP piping,

please suggest me best suitable CAESAR material model for DI piping.

Khaja,

The common available ductile iron pipe material used in USA water distribution systems is ASTM A395. You might have some different DI material for your purchasing area. Properties for sand cast pipe are different than centrifugal cast pipe. Almost all fittings are sand cast. The CAESARII materials database includes grey cast iron and wrought iron which might serve as template for editing to the material properties of the ductile iron available in your area and for the national piping code to be applied in your area.