kalidor

Posted: Fri Jul 08, 2011 8:13pm
Post Subject: Fresh Water tankI have just cleaned and coated the fresh water tank on my 1991 Liverpool built boat. Occasionally when running the fresh water pump I get a loud bang out of the plating on the tank due to I assume a vacuum. The filling line was extended, before we bought the boat, so that it was outside the cratch cover. To stop this banging I have drilled a small hole near the top of the pipe extension. What should be in place to stop a vacuum forming and where should it be situated. I have looked in all the front lockers and as stated I have been in the tank cleaning it?