Racor Fuel Filter Location

[orion1]

My Racor is and has apparently always been mounted in its current location. It is mounted near the bottom of the fuel tank app. 18" below the top. Both the feed line and the return leave the top of the tank and go directly to the filter. The filter is even with the top of the engine.

This arrangement has apparently always worked well. I have put 100 hours on it since purchasing the boat, with no problem. The filter bowl seems clean. It is time to change the element and I am curious about something, which has caused me to hesitate.

The fuel line from the tank to the Racor has no shut off valve. If I remove the spin on filter, will the fuel pour out from suction? I feel that there should be a shut off before the filter anyway. The previous owner always had his mech do the maint and therefore cannot help.

[AnchorageGuy]

Gravity certainly should take over when you open up the filter. You should most certainly have a fuel cut off at the pick up on your tank or at least between the tank and the filter. How would you cut off the fuel supply in case of an emergency? BTW, are you certain the return line runs through the Racor? This is a bit unusual.

[never monday]

Originally Posted by Chuck Baier

How would you cut off the fuel supply in case of an emergency?

vice grips clamp the fuel line nicely.

[AnchorageGuy]

Originally Posted by never monday

vice grips clamp the fuel line nicely.

Yes and they also tear holes in the lines. Much better to have a valve to do that.

[never monday]

Originally Posted by Chuck Baier

Yes and they also tear holes in the lines. Much better to have a valve to do that.

are we talking proper or emergency? I thought you mentioned emergency measures.

[AnchorageGuy]

What I meant was that it needs to have a proper cut off valve in case of an emergency

[orion1]

Thanks all, I totally agree on the valve and will install one as soon as I do the deed, but did not know exactly what to expect when the filter element was removed. Vice grips would certainly work in an emergency. Hope that does not happen yet.

The return line does not come from the Racor but from the engine and follows the feed line back up to the tank. Sorry about the confusion!

Guess I will install a valve at the feed line tank exit, that way I can remove it without filling the bilge and only loose the fuel in the short line. Have never had tank above the filter before.

[David M]

Put a valve in your return line at the tank as well.

[AnchorageGuy]

Originally Posted by David M

Put a valve in your return line at the tank as well.

and that would be why?

[David M]

You want a valve wherever you have a potential source of fuel for safety reasons. Even a return line can back flow under the right circumstances. I have valves on both of my return lines at the tank (twin engine). The Coast Guard required it when it was a Subchapter T vessel.

[AnchorageGuy]

Most return lines I have encountered are simply connected to a fitting in the top of the tank with no pick up tube. So unless the tank is overfilled it is very unlikely the fuel can back siphon from the tank and a valve would not stop a leak in the return line.

[David M]

I never said a siphon effect.

"unless the tank is overfilled"...that's never happened? You have never had large waves that cause the bow to dip? You have never had the tanks full with a big list where you know the fuel is pressing against the top of the tank?

Stuff happens. Hopefully you will never need that valve.

[AnchorageGuy]

Originally Posted by David M

I never said a siphon effect.

"unless the tank is overfilled"...that's never happened? You have never had large waves that cause the bow to dip? You have never had the tanks full with a big list where you know the fuel is pressing against the top of the tank?

Stuff happens. Hopefully you will never need that valve.

Not sure how some handle it offshore but under way in any seas large or small and that includes gales in the Gulf Stream we have never closed the valves on our fuel tanks. Not saying it should not be done just asking why. In all of the years I have been working on boats and there have been a lot of them, I don't recall ever seeing a valve on a return line. Forgetting to open it could cause a problem. If you forget to open your intake line the engine will shut down at worst.

[orion1]

I'm not sure but it just occured to me that it may make a difference from a gravity standpoint since the filter and the end of the pick up tube are at about the same level. Maybe that will lessen the amount of siphon potential. Just wondering how they did the change in the past.

If I place a valve at tht top of the tank, the tube below the valve would drain when the filter element is removed. That might make it hard to get flow after valve is reopened, without turning over the engine.

Wish I understood the fuel system better. Need to read more I know.

[AnchorageGuy]

Not necessarily since there needs to be air or more fuel behind it to allow the fuel to flow. Yes some might leak out but most will not since with the valve closed and the line full of fuel it almost creates a vacuum that keeps the fuel from running out. depending on your engine, etc. you will at least need to fill the filter with fuel or use a pump, the one on the engine, to bleed the system and or fill the filter each time you change it. It is kinda like sticking a straw in a glass of liquid, putting your finger over the straw and pulling it out. The liquid stays in the straw.