wing tank plumbing

[NY86]

Re: wing tank plumbing

it tees into the back of the fuselage tank near the the bottom.

Is something else connected there too? Any chance there's a standpipe inside the tank to put the outlet above the normal fuel level? (Otherwise, why wouldn't it be at the bottom?)

[flyguy]

Re: wing tank plumbing

Nah, I'm not going to comment on the logic of putting 12 gallons of highly flamable fuel just above the pilots lap. Perhaps the same train of logic for the T ? Chuckle.
DC

[Mark Julicher]

Re: wing tank plumbing

The same logic for the nose tank is why the fuel tank on a Willy's Jeep was under the driver's butt. AND there was the potential for taking a bullet and scorching valuable anatomy.

[Guest]

Re: wing tank plumbing

Is something else connected there too? Any chance there's a standpipe inside the tank to put the outlet above the normal fuel level? (Otherwise, why wouldn't it be at the bottom?)

nothing else there, just a pipe thread fitting to fill the tank from the back.

[Hank Jarrett]

Re: wing tank plumbing

Neat, mine was set up to be down while draining and either forward or aft when closed (can't remember). The placard was original and didn't allow for up and forward.
Since I am making all new placards it would be easy to change. Think that violates any "rules"?
Hank

I also like the larger "plate" behind the valve so the handle doesn't rub the headliner and make a hole or tear in it.

[NY86]

Re: wing tank plumbing

nothing else there, just a pipe thread fitting to fill the tank from the back.

No chance there's an elbow (pointing up) on the inside of the tank?

[Guest]

Re: wing tank plumbing

No chance there's an elbow (pointing up) on the inside of the tank?

no

[VictorBravo]

Re: wing tank plumbing

Install a check valve to prevent fuel from flowing out of the main tank and into the wing tank lines???

All of this would require an approval to be legal of course. However, from a purely mechanical standpoint, I'd vote for the two-valve system instead of the check valve. One at each tank outlet at the wing root, one at the T where those wing feed lines go into the tank, and then a "stock" main shutoff valve at the bottom of the main fuel tank upstream of the firewall.

This means a total of four valves in the airplane for people wanting the utmost in leak-stoppage ability, but indeed each of them would have a function. But doing it this way adds its own complexity and actually adds more locations where some piece of hardware could leak.

So it's a judgment call - choose between lowest parts count/least # of leak points, and being able to isolate a leak from the most angles.

[NY86]

Re: wing tank plumbing

Or, build a standpipe into the tank...

http://www.ercoupe.info/uploads/Main/drawings/a-512.jpg

[mulwyk]

Re: wing tank plumbing

Here's a picture of my valve installation. I scaled Howards photo and placed my valve in about the same position. My installation IS different from Howards: I don't have headliner, and I used a modern valve (Apollo 76).

Just above the valve is that "half empty" placard and above that is a 3" inspection hole. The valve lever is pointed forward (left in the photo) when in the open position.

[Pearson]

Re: wing tank plumbing

Bob,

Your fuel valve in that picture is located about 6 to 8 inches forward of where mine where before I relocated them to beneath the instrument panel.
I don't know if this is because my tank's outlet is farther aft than yours or what, but I think this is curious because I thought all those wing tanks were the same. It makes me wonder how much unusable fuel you have in that tank.

Regarding locating the valves at the root or beneath the panel; I moved mine from the wing root to the bottom of the panel because I had drawn blood from my head on several occasions.

I took my plane to a reputable mechanic and explained that I didn't want to trade knee skin for head skin. We located the valves far enough forward from the lower edge of the panel that my knees have never made contact. You can't see the valves or the handles, but when you put your hand under the panel, you quickly feel the valves. We fabricated a piece of L bracket to act as a brace so the valves are very solidly mounted. It was the best thing I ever did to my airplane.

As an aside, while we had it all apart, this mechanic took the packing nut off the valves and sprayed WD-40 liberally on the insides. Ten years later my valves still work like new.

[mulwyk]

Re: wing tank plumbing

Hi Richard:
You're right, the tank outlet is about 8" aft of the valve location. I wanted to locate the valve so there was a direct connection straight out of the tank but 4 things made me choose the more forward position you see in the picture: (1) the infamous head banging problem. The aft valve location is directly in noggen-thumping range, but 8" forward it looks like you'd really have to stretch to get your head up there. (2) Howard's photo. I measured (as best I could) the distance from the valve to the door post in Howard's photo. It looks like Howards valve is definetly forward of the tank outlet. (3) I measured the room in there from the valve to the tank outlet, if I was to make a direct connection. 2.3"! Didn't seem like enough for my plumbing skills. (4) Some evidence from the collection of fittings I got with the project that the original installation used a elbow out of the tank, a short length of hose and then somehow connected to the valve.

Well anyway (sorry that got so long) I decided to locate the valve almost 8" forward of the tank outlet.

[1938BF50]

Re: wing tank plumbing

Does anyone have a pic of the tubing and connections used between the tank and valve in this forward mounted location. I like that layout and will do it for both wing tanks. Any "rubber" tubing used for vibration isolation anywhere between the valve and tank?

[Joel Severinghaus]

Re: wing tank plumbing

Photos attached of my wing tank fuel transfer valve and line. The line comes down the front of the door post, beside the aileron cable, and connects to the main tank on the main tank's lower rear face, just in front of the throttle knob in the attached photo.

I only use this valve when I'm carrying the extra six gallons in the right wing for a long cross-country, and then close the valve after the ten minutes it takes to drain the wing tank into the main tank. And I touch the wing tank valve again to make sure it's closed, when doing a GUMPS checklist before landing.

My wing tank valve doesn't protrude below the door frame -- my problem has been passengers snagging clothing on the corners of the backing plate behind the valve, so I rounded and beveled its edges during last summer's restoration work, which seems to help.

By the way, there's a 1970s Taylorcraft factory parts price list which says for placard B12-307-1, "Note: Bulletin Sept. 15, 1970 -- This placard now reads 'Refill main tank in level flight and only when main tank is less than half full' and must replace old placard." I just phoned Antonio in Brownsville and bought a new old stock factory placard and stuck it on...

[1938BF50]

Re: wing tank plumbing

Thanx Joel,

Do you have any pics of the plumbing behind the plate? I talked with my IA last night and he was not going to sign off on "hardware" valves, so I will need another Imperial valve for the LH wing tank. I am wondering how some of you have handled the plumbing between the tank outlet and the valve. I would think some Aeroquip hose would be best for vibration in this section.