Anti Siphon check valve required? When?

[HT32BSX115]

Howdy all, <br /><br />I found the anti-siphon (check) valve sticking. So I had a look at where it is in the fuel system....it is of course connected directly to the fuel output fitting on top of the tank.<br /><br />The fuel tank is below the floor and the fuel has to literally go "up hill" to get to the fuel filter and further uphill to get to the carb.(no part of the fuel line goes below the output fitting on the top of the tank.)<br /><br />Anti siphon valves are REQUIRED any time the fuel tank top is higher than the carburetor... or the fuel line goes lower than the top of the tank etc (see the below link)<br /><br /> http://www.uscgboating.org/safety/boatbuilder/fuel/183-568.htm <br /><br /><br />It appears that Four Winns put this anti-siphon valve in this boat even though it's not needed or required by Federal Law.(they probably put them in all their boats by default whether needed or not!)<br /><br /><br />Can anyone think of any other reason I would need to leave it in there? <br /><br /><br />Thanks, <br /><br /><br />Rick

 

[Laddies]

Re: Anti Siphon check valve required? When?

Coast Gaurd reqs. a anti siphon vavle on all boats with a inboard engine

 

[Don S]

Re: Anti Siphon check valve required? When?

Keep it as a safety device, even if you could find a legal reason to remove it. If it's sticking, just replace it with a new one. They are a very inexpensive item to replace.

 

[rodbolt]

Re: Anti Siphon check valve required? When?

I am with Dons.<br /> if no portion of the fuel system drops below the level of the tank the valve is not required, however if a line breaks or gets dropped and falls below the level you may be glad its there. I see a lot of them get blamed but its actually rare to see a failure with a modern valve, years ago they had an oring that was very problematic, now its a stainless ball with a spring behind it that pushes the ball onto the seat vacum from the pump will overcome the spring and allow the ball to move.<br /> I would verify it with a vacum test on the fuel system.<br />we have more problems with the "hidden" screen in most fuel draw tubes.

 

[HT32BSX115]

Re: Anti Siphon check valve required? When?

Well according to the link I provided, they don't.<br /> (this of course doesn't mean the link is accurate either I suppose) <br /><br /> http://www.uscgboating.org/safety/boatbuilder/fuel/183-568.htm <br /><br /><br />As indicated an anti-siphon device or shut-off valve is only required if any portion of the fuel supply line drops below the top of the tank or as indicated below.<br /><br />Click below:<br /><br /> http://www.uscgboating.org/safety/boatbuilder/fuel/_GIFS_FUEL/FUEL-F34.gif <br /><br />My case is similar to the first example in the picture.<br /><br /><br />Now. It may be "Good practice" as Don indicated to have it anyway. (which was my original question...Thanks by the way, Don!)<br /><br /><br />Regards, <br /><br />Rick<br /><br /><br />

Originally posted by Laddies:<br /> Coast Gaurd reqs. a anti siphon vavle on all boats with a inboard engine