• Anti - Siphon Valves

    Anti-Siphon valves are an integral part of the marine fuel system. There main function is safety related. They prevent a ruptured or leaking fuel line from filling your bilge with explosive fuel.

    How an anti-siphon valve works is actually quite simple. Attachment 427The valve which is really a fitting has an orifice through which fuel passes, on the downstream side of that orifice is a small steel ball. The steel ball is held against that orifice with a spring. If their is no suction from a fuel pump on the downstream side, the spring presses the steel ball against the orifice effectively blocking the fuel flow. Once the fuel pump develops sufficient pressure the steel ball compresses the spring and unseats allowing fuel to flow.

    Debris or corrosion due to water in the fuel are the two most common culprits that cause these Attachment 429valves to malfunction. If you suspect you have a malfunctioning anti-siphon valve you can remove it and install a threaded nipple into the fuel line to see if the problem goes away. If this resolves the problem you can try cleaning the valve with carburetor cleaner or by blowing air through it with an air hose. If it is clean you should be able to blow air through it in one direction only. If the valve is bad don't leave the fuel line unprotected without an anti-siphon valve, replace the faulty one with a new one immediately.

    Attachment 431

     

  • Recent Forum Posts

    Cap'n Ray

    I agree with Tim! Got your message Rick, a reply...

    I agree with Tim! Got your message Rick, a reply has been sent! We are all waiting with bated breath to hear how things are going. Hope all goes as smoothly as possible and your recovery is swift!...

    Cap'n Ray Yesterday, 23:22 Go to last post
    Cap'n Ray

    A picture is worth a thousand words. That being...

    A picture is worth a thousand words. That being said, maybe they're not metric? A "line wrench" is a good choice on the fittings you're likely working with (like a boxed end wrench with one small...

    Cap'n Ray Yesterday, 23:17 Go to last post
    Cap'n Ray

    Thanks Tim, enjoy your weekend and be safe. We...

    Thanks Tim, enjoy your weekend and be safe. We will be taking the 'Go fast' out on Monday if the rain lets up! (Otherwise we may just unhook the bow and transom straps and float off right here in the...

    Cap'n Ray Yesterday, 23:12 Go to last post
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