I fitted one that looks like this Vetus FTR140 Series Cooling Water Strainer
about 5 years ago and it works really well . I live aboard
and do 300 – 400 hours a year and my impellers are lasting about 2 years before they start shedding blade tips.
It has become part of the standard daily engine inspection
to look into the strainer and check it only has water
I mounted the strainer above the engine
and then took a pipe from the output side of the salt water pump
to the input of the strainer and then from the output side of the strainer to the heat exchanger
I have a Perkins
4236M and it a real pain to open up the heat exchanger and a serious real pain if the heat exchanger has to be removed.