I'm re-doing the hoses for the head (fun job). The boats I am familiar with have not had a vented anti-siphon in the supply hose to the head, it just runs straight from the seacock to the head. After checking Nigel C's book, it looks like there should one. My question is how would that work? If you have a vented anti-siphon (air in the hose at the loop) how are you going to develop any vacuum at the pump in the head (PHII) to draw any water in, seems to defy the laws of physics? What am I missing here? Do your systems have a/s before the pump on the supply? Thanks, I only want to do this once
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John