I think your surveyor was probably commenting on the gate valves. They were commonly used on many boats decades ago, and are a poor choise. Usually made from brass instead of marine quality bronze they were a big source of problems.I have often replaced these with either Bronze (Groco) or Marelon (Forespar) ball valves. Check out Wests catalog for good advise re: thread types. NPS does not mate with NPT(pipe) thread properly. Thru hulls are NPS, and may not neccesarily need to be replaced.
Btw: I would NOT combine any other fitting to the raw water intake. If your engine cooling pump sucked air the result could be most regretable
Last edited by HowardP; 01-29-2011 at 10:10 PM.
Reason: spelling error