Originally Posted by Maine Sail
But that pretty much defeats the entire purpose of the check valve. A siphon break is still a choice that won't stick closed. If you are not preventing hose drain back then there is little point for a check valve...... Bilge pump hoses should always be installed to prevent back siphoning which includes a high loop and a siphon break....
Agreed, you need to prevent back siphoning which includes a high loop and a siphon break.. but you're quite wrong
about having the check valve up high defeating the purpose. Hose drain back is irrelevant - it's, what, 1 litre of water max?
Think about what happens when you put the gunnel under on a flush-deck boat with the bilge pump exit out of the side just above the waterline - even with a high loop and a siphon break.
Boats have sunk because of that.