Exhaust backflow

[partgypsy]

I am replacing the 40 year-old exhaust on my 47' Chris Craft with 8v53 diesels. It originally had a cast iron backflow preventer in the 6" straight exhaust system. This item has rusted out and is no longer useable. I can't find a similar item to replace this. The riser on this engine is about 18" and the exhaust tips at the transom are the type that turn down and out at an angle and will help somewhat, but the exhaust is low to the water line and I don't feel safe without somthing to keep the water from rushing into the engine. Is backflow preventer the proper name for what I'm looking for, or are they called something else? I can't find them on the web. Would an industrial 6" iron check valve be the same thing?

[Bglad]

http://www.centekindustries.com/accessories.html

The link is for a fiberglass check valve made for marine exhaust systems.

Here you can find more:

http://www.vetus.nl/

and if only the right terminology.

Regards
Richard

[FAST FRED]

www.mesamarine.com/

Look there,

FF