Info on big bore valves

Does anyone know of a good resource for details of big bore valves ?

Most of the info I have (API 16.10, Trouvay etc.) only goes up 24" (less for higher ratings) so where is the best place to get info on say 16" 2500# ball valve or a 42" 300# globe ?

I usually assume a size for the initial design based on scaling up a smaller version, and then modify it with the correct information when I receive it from the manufacturer, which normally works pretty well, but it would be nice to have a little bit more accurate info up front (story of my life eh? )

Thanks in advance

Jop is correct on this. I am a big advocate of using the manufacturer's sales engineering staff. That's what they are there for and they are really a great source of info. They are more than happy to assist you at any time.

sorry, I should have given you info on mfg'rs. I usually go to 'Global Spec' search engine and search on 'valves'. this takes me to a page where I can input various requirements thus finding manufacturers.

Thank you both for your help and your prompt response.
That's certainly an avenue worth exploring further, however, as there are very few UK based valve manufacturers it's sometimes difficult to get information quickly. Furthermore, in the past some vendors have been reluctant to spend time supplying information if the project is outside of their normal supply (i.e they might not normally supply to the middle east or are not on the approved vendors list for the company you work for)
Is there anywhere else i could go for info ? (standards, on-line catalogues etc.)

thanks again