Thanks to all who helped with your info, pictures, specifications and comforting words relative to my recent sea-chest lid problem.
The discussion has evolved a bit but here are my observations:
When flushing my systems with fresh water I have always used dock or yard water directed at full force into the open sea-chest. In my current slip I have unbelievable water pressure. With one exception, I have never been able to keep up with the demand of the Calpeda or March AC pumps or the Onan or 75 hp Yanmar engines. No problem keeping up with the demand of the head pumps and I long ago did away with the sea water anchor wash down pump and changed to a fresh water anchor wash (Joel's friend, Ray Eaton, now deceased, installed that for me in Ft. Lauderdale).
The exception I noted above, was when I once found I was able to keep up with the Yanmar throughput. I next checked the Yanmar impeller and found I was missing three vanes. So being able to evaluate how much water is being consumed from the sea-chest is a diagnostic aid about the health of your impellers for the engines and other sea water consuming accessories.
Thanks again all,
SM 2000 #335
Puerto Del Rey Marina - Puerto Rico