Anti Siphon Valve OK

I have just checked out the anti siphon valve.

I left the hoses in place and removed the nut holding it to the bulkhead so that I could work with it. It was already in the "open" position because when I blew down it the air passed through with no movement of the valve. When I sucked up the valve closed blocking the flow of air. The action of the valve was amazingly free and effective given the salt water environment it must deal with. There was no hint of stickiness or poor seal.

The photo shows the valve where Zee re sited it to get it higher above the water line. According to my measurement it is about 900 mm (3 ft) above the waterline, 250 mm (10 in) from the center line of the boat.