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Andair Fuel Valve Install - need ideas

Saville

Well Known Member
Andair Fuel Valve Replacement Installation - Design

I have a LEFT - BOTH - RIGHT - OFF Andair Fuel Valve installed in my -8.

Given that I have a new left tank being built I decided to replace that with an Andair LEFT - RIGHT - OFF.

The present installation is beyond hideous. Extremely difficult to remove the panel to look down there and/or tighten the B-nuts.
Here it is:

Fuel_Selector_Bay_Flange_Pointer_Scaled.jpg


I notice in the plans that if you have the Van's valve you install it using bracket F-883A:

Fuel_Valve_0001.jpg


Here is Detail A on the plans:

Fuel_Valve_Detail_A.jpg



But Andair Valves won't fit inside the bracket. Something else has to be done.

I have 2 ideas:

1) Make a new bracket, using the same thickness material, that is wide enough so that the Andair valve can fit. Rivet that to the flanges. It would be hard to get in there and rivet new support cross member to the flange that's riveted to the skin.

2) Make a new cover plate out of 0.064 sheet aluminum and mount the Andair directly to that using nutplates.



Any ideas wold be welcome. Especially if you've retro-fitted an Andair valve to an already built airplane.

Yes I know the wires have to be gotten out of the way.

Thanks !
 
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See if this helps you.

I made a new bracket, by using the one that came from Vans, used as a template.
But made it much more wide. I just bent some 0.030 I had laying around in trim scrap.
I cut and bent one side for a Z bend such that it raised that side of the bracket to be flush with the console cover sheet.
Then for the other side had to make an extension and formed it in a Z bend to again raise that side of the bracket up to be flush for the console sheet.
Photos will explain. If you want to see original images so you can zoom up, just PM me.

Also, a major part of this, I said to H E L L with bending tubing for all this. That is ridiculous. Call Tom at TS flightlines and have him make you some high quality hoses. Bending tubing into this spaghetti nightmare is over rated.

IMG_3587.jpeg


IMG_3585.jpeg


IMG_3584.jpeg
 
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fuel valve installation

No matter what you do, it will not be easy to get access to the valve. I was literally down there today, trying to track down a small whiff of fuel smell. I think I found it.

Here are some old pictures. I've changed it a bit, but not much.

http://www.rv8.ch/andair-fuel-valve-installation/

Not much magic here, just find a way to hold the valve stable, and then get the cover on it, mainly for cosmetics. I kind of wish that the holes in the fuel valve were threaded - that's the hardest part, getting a socket underneath there to hold the nut while turning the screw at the top. I think I need to get into yoga.
 
Here's how I mounted mine. Basically, I ran two pieces of angle between the aux longeron and mid-cabin brace; those two pieces are in turn tied together with a piece of sheet aluminum that the valve itself mounts to.

I can't say anything about what it's like in service since I'm not flying yet, but all the nipples on my Andair valve point down, so I don't expect that it'd be as terrible to deal with as yours is. We'll find out maybe later this year if I'm wrong about that...

IMG_6758.jpg
 
access when fully assembled

Philip, I'm sure you know this, but I would be very careful about doing the install with the side skin off to make sure that you can maintain it when you are flying. I didn't have any choice since I had a QB. Working on it from a sitting position is not easy (at least for me). If I have to do anything serious there, I'll remove the seats, put down some old foam, and lay down.
 
See if this helps you.

I made a new bracket, by using the one that came from Vans, used as a template.
But made it much more wide. I just bent some 0.030 I had laying around in trim scrap.
I cut and bent one side for a Z bend such that it raised that side of the bracket to be flush with the console cover sheet.
Then for the other side had to make an extension and formed it in a Z bend to again raise that side of the bracket up to be flush for the console sheet.
Photos will explain. If you want to see original images so you can zoom up, just PM me.

Also, a major part of this, I said to H E L L with bending tubing for all this. That is ridiculous. Call Tom at TS flightlines and have him make you some high quality hoses. Bending tubing into this spaghetti nightmare is over rated.

IMG_3587.jpeg


IMG_3585.jpeg


IMG_3584.jpeg

Yes! Just went thru this. Tom as TS Flightlines will make this job almost pleasant.......well, not terrible.
 
Here's how I mounted mine. Basically, I ran two pieces of angle between the aux longeron and mid-cabin brace; those two pieces are in turn tied together with a piece of sheet aluminum that the valve itself mounts to.

I can't say anything about what it's like in service since I'm not flying yet, but all the nipples on my Andair valve point down, so I don't expect that it'd be as terrible to deal with as yours is. We'll find out maybe later this year if I'm wrong about that...

IMG_6758.jpg

I'm considering this form of installation but I have two questions:

1) What did you use for the angle aluminum supports?


2) The excerpt from the drawing which I included above shows 3 rivets
at each end of the F883A Fuel Valve Bracket.

Your installation shows one at each end of the angle for a total of 2.
So that means that the weight of the installation is born by a total of 4 rivets
and not 6.

Is this sufficient (I wonder) to keep the valve from moving under G?

I had the same idea as yours but I was wondering about the strength
of the install.

Thanks!
 
Excellent Timing!

Just about to begin this process myself.

Haven't opened it up yet. But now I have some great ideas for what ever I find down there.
 
The clocking of the Left fuel port of the Andair fuel valve left it situated too close to the fuselage skin for me to route the fuel line without resorting to the 90 deg elbow, which something to be avoided according to Dave Prizio advice on the fuel-system

What I did was to move the fuel-valve inboard about 1.5 inches in order to have more clearance so I can run the left tank fuel line with more gradual bends. I've been working on this fuel valve since Monday night and I am struggling a bit due to the tight clearance of the left fuel port. I don't have a picture of the final assembly yet.

To answer the question about the g loading of the mount. The original Vans fuel bracket is only 0.040in thick so using the two thicker angles should be beefier. Also, there is another 0.032" cover plate that is mounted on top of the fuel valve. Three screws will go through the cover plate down to the nut plates on the valve to keep everything tight. So the support comprises of the cover plate, fuel bracket angles, side longeron, mid-cabin support, and the fuel valve structure working in unison and nothing will move under load.
 
The clocking of the Left fuel port of the Andair fuel valve left it situated too close to the fuselage skin for me to route the fuel line without resorting to the 90 deg elbow, which something to be avoided according to Dave Prizio advice on the fuel-system

What I did was to move the fuel-valve inboard about 1.5 inches in order to have more clearance so I can run the left tank fuel line with more gradual bends. I've been working on this fuel valve since Monday night and I am struggling a bit due to the tight clearance of the left fuel port. I don't have a picture of the final assembly yet.

To answer the question about the g loading of the mount. The original Vans fuel bracket is only 0.040in thick so using the two thicker angles should be beefier. Also, there is another 0.032" cover plate that is mounted on top of the fuel valve. Three screws will go through the cover plate down to the nut plates on the valve to keep everything tight. So the support comprises of the cover plate, fuel bracket angles, side longeron, mid-cabin support, and the fuel valve structure working in unison and nothing will move under load.


My concern with regard to G loading is not the beefiness of the components.
And in both cases (Van's and your description), the mounting screws for the valve go through all the components and the cover plate is fastened to the same structure..

It's that the angles and sub-plate attached to the airplane with 4 rivets instead of 6 for the bracket. Everything else is exactly the same.
 
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My suggestion is use a .040 or .063 plate to replace the stock .032 shelf, cut hole big enough for the Andair valve to mount thru & drill the 3 screw holes with nutplates. No need for angles or other structure, check how valve is installed in 6/7/9 if you have doubts.
Fashion a copy of your plate that can position the valve temporarily but trimmed to leaves access for fitting plumbing. Once plumbing done the temp plate can be changed out for the shelf plate.
 
My suggestion is use a .040 or .063 plate to replace the stock .032 shelf, cut hole big enough for the Andair valve to mount thru & drill the 3 screw holes with nutplates. No need for angles or other structure, check how valve is installed in 6/7/9 if you have doubts.
Fashion a copy of your plate that can position the valve temporarily but trimmed to leaves access for fitting plumbing. Once plumbing done the temp plate can be changed out for the shelf plate.

I assume you use nuts and bolts to attach the valve to the 0.064" thick shelf plate?
How do you use nutplates to attach the valve to the shelf plate?

I was hoping to work out a way to be able to remove the shelf without unscrewing the valve. I was thinking of using Phillip's method (N546RV in this thread) with one modification:

Cut a 3" hole in the shelf so that the screws for the valve do not go through the shelf. The hole goes around the valve label plate. That way I can remove the shelf and get at things without having to disturb the valve installation.
 
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3 designs

Ok Thanks to lots of helpful people here, I've boiled things down
to 3 designs. One change I make to all of these ideas is
that the screws that connect the valve to the support structure
will NOT go through the shelf cover. I will cut a 3" hole in the
shelf cover and the label plate for the valve will sit in that hole.
This way I can remove the shelf cover without having to unscrew
the valve - extremely difficult for me to get nuts started on the
valve screws in such tight quarters.

One design goal is to make access to the area under the shelf
cover plate easier than it is now.

1) DESIGN 1:

Van's design only larger

This one came from Dan K (who has been enormously helpful
offline - thanks Dan). Essentially you make a new F-883A
bracket only wider to accommodate the Andair valve. In the
following picture, the original Van's bracket is on the right next
to the file. Dan's new bracket is on the left:


Dan_K_Wider_bracket.jpg


In this next picture, Dan is fitting the bracket and valve in the
plane. He moved the position of the valve aft and inboard - I
intend to do the same:

Dan_k_temp_install.jpg


Pro: Uses Van's design so strength should not be a problem

Con: Have to drill holes in the longeron flange and set
nutplates in very tight quarters.
Makes access to the valve connections tough.




Design 2: Angle instead of bracket.

This one was suggested by Phillip (N546RV). Essentially the
same as above but instead of a full bracket, mount a plate on
two pieces of aluminum angle.

Design_2_sample.jpg


Pro: Opens up access to the interior a little more than Design 1

Con: Not sure what size/thickness angle to use to generate the
same strength and Van's design (Also 2024T3 angle?)
Have to drill holes in the longeron flange and set
nutplates in very tight quarters.
Makes access to the valve connections tough.


Design 3:

One thick shelf cover - no underlying support structure.

This is a refinement of the first idea I had. Ralph Inkster had a
similar suggestion. Instead of the thin cover shelf material called
out by Van's, use thicker plate. No underlying structure.

1) Replicate the cover plate in 0.04 or 0.064.

2) Cut a 3.125" hole which will accommodate the valve label plate:

Hole_In_Cover_Plate.jpg


The 3" diameter label plate will sit in the hole:

Label_Plate_thru_Cover_Plate.jpg


3) Cut a piece of 0.064 4" square.
Cut a hole in it to accommodate the ~1" valve mounting
hole.
Screw the valve to the small plate with screws, washers, nuts.
locate nutplates at each corner of the smaller plate.
Screw the cover plate to the "under plate"

Design_3_Fuel_Valve.jpg


The shelf cover is in blue. The "underplate" is green, the valve is gray;
the red lines are screws.

The thin line object in the 3.125" hole is the "label plate".
I can remove the cover plate by removing the screws around the periphery
and the 4 screws holding the under plate (green) to the cover plate (blue).

Pro: No structure need be made and fastened to the
aircraft. No holes drilled; no nutplates set. Very
tight in there.
Great access to the interior of the bay. No support
structure getting in the way.

Con: Not sure the 0.064 is still enough to keep the
valve from moving under G.

Ralph says that the RV 6/7/9's do it this way. I don't have access
to those plans. I'd like to see how Van's designed that.

Comments and criticisms welcome.
 
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valve moving

...

Con: Not sure the 0.064 is still enough to keep the
valve from moving under G.

...
I think that will be fine. I have the return fuel lines as well, and it's very rigid just floating in space supported by the aluminum tubes. If you don't have the return lines, you've still got three tubes. If you use flexible hose, even 0.064 is pretty strong.
 
Larry Larson was kind enough to give me the dimensions of the F983A fuel valve plate on the RV-7 - 4.75" square and 0.063 thick.

The RV-8 valve plate is 12" x 8".

This makes me wonder if Design #3 would be strong enough
 
I am working on the solution in this picture.

Dan_k_temp_install.jpg


The access to the valve inlet is very tight because the Andair valve is so much shorter than the Vans stock valve. I am still working to route the L/R tank fuel lines but it is doable.
 
0.063 Should be ok

Having forgotten any slight bit of structures I may have learned getting my Aerospace Engineering degree (back in the stone age), I looked around the Web to find a calculator that would give me the deflection of the shelf cover it it was clamped at all 4 edges, and the Andair experienced +6G.

I assumed the valve was 0.5 lbs, and was located in the center of the plate. I also assumed that the load would be applied in the area of the ~1.125 diameter "neck" located at the center of the shelf. Shelf dimensions are 12.5" x 8".

This web page:

https://eicac.co.uk/calculators

has a multitude of great calculators. A real find.

So here is the output of the first run with the above data:

Calculator_2.png


The deflection seems to be so small that it's below the accuracy of the model. But just to be sure, I put 80 psi as the load to see if I got a reaction from the model:

Calculator_2_at_P_80.png


Got some reaction that time so the model is trying to calculate.

The results suggest that using 0.063 2024 as a mount for the valve will work just fine.
 
Gregg----with the time you have invested in making a bracket in CAD and researched metal strengthes, you probably could have mounted the valve and the rest of the fuel systems. We've seen them with alot less elaborate mounting plates that have lasted years under all kinds of conditions.
.063 is plenty strong. Once its either riveted or screwed into the side bracket, it ties it all together.

Tom
 
Gregg----with the time you have invested in making a bracket in CAD and researched metal strengthes, you probably could have mounted the valve and the rest of the fuel systems. We've seen them with alot less elaborate mounting plates that have lasted years under all kinds of conditions.
.063 is plenty strong. Once its either riveted or screwed into the side bracket, it ties it all together.

Tom

Yes Tom it's true that I tend to approach these things slowly and carefully - but mainly slowly - especially when I'm looking to do something different from the plans.

Experience with having to connect and disconnect the left hand tank several times taught me that I have to design in whatever convenience I could arrange. So that takes me time as well because the final idea is rarely the one that arrives first...or second....

And then once I select the method I work through each fabrication and installation step in my head many times while I'm waiting for the delivery of the tools and materials that I do not have on hand (I'm not a metalworker).

But I now have almost all the tools I need and most of the 0.063 I need to begin so this weekend the fabrication begins.

But you may rest assured that once the valve is sited I'll be taking whatever measurements are necessary - to whatever degree of accuracy you specify - and ordering flexible fuel line hoses from you.

I will need 3.
 
LOL---Gregg---we all play out of the box at times. And yes moving the valve in an 8, means really thinking about the left tank line.
Because of what we do, we try to keep things as close to plans as possible--to try and make is easy for the builders, especially those with QB fuselages.
BUT--we're always up for a challenge!
Tom
 
I finally had the Andair fuel valve and all the plumbing done!

I had to smack my head after I discovered the inlets on the Andair fuel valve can be pointed downward instead of clocking sideway as packaged from the factory. I had a lot of problems bending the fuel tubing with the factory sideway clocking. After I pointed them downward, fitting the fuel line was a breeze, taking only 1/2 day versus a few days of sweating and swearing.

After I buttoned everything up, the handmade 0.064" doubler support plate was tight as it was fastened with all the screws from the cover plate.

I feel like I am making good progress. Next item
 
And yes moving the valve in an 8, means really thinking about the left tank line.

BUT--we're always up for a challenge!
Tom

Won't be much of a challenge. I'm moving the valve aft so that that a single 90 degree bend coming off the left tank EF20 is all that's required. The line should line up with the center of the hole.
 
Progress Report

Ok so I thought it would be time to give a progress report.

I've been working away at this for a while, and I'm at the point now where all the structural work is complete and I can start on the fuel lines. I get the fuel lines made and installed and this project is complete (..so I can move on to the next one prior to flying)

Just to recap:

My left tank was leaky and it turned out that the Proseal never cured - probably due to residual gas in the tank. So I had a new tank made. It's now installed:

Tank_On_1_640.jpg


I needed the new tank to be installed in order to measure and cut the fuel line that goes from the selector to the tank.

The old selector was an Andair LEFT-BOTH-RIGHT_OFF selector and I wanted to replace that with an Andair LEFT-RIGHT-OFF. Every time I take on a task like that I try to make things better. The old selector mounting scheme was very poor ( See Post #1 in this thread) and I wanted to replace that with a better one. And I wanted the new scheme to make it easier to get to the fittings. So I designed this installation scheme so that the fuel selector was not mounted directly onto the cover plate - it's extremely difficult to unmount it because you have to get a wrench on some nylon nuts - enormously difficult in this tight area. So I worked out a design such that if I ever needed to get down into that bay, I could un-mount the fuel selector from the bay cover plate from the TOP:

Design_3_Fuel_Valve.jpg


So after getting some 0.064 aluminum plate, I made a new bay cover (blue line in the above picture) and an underplate (green line). Figuring out a way to locate the holes in the new cover plate was difficult but I settled on this one, which worked:

I made a plywood copy of the cover plate.
Put some duct tape along the edges.
Laid the plywood plate in position and ran one screw backwards UP the nutplate until it hit the duct tape, and left an impression:

Screw_Location_1_640.jpg


with a close up:

Screw_Location_2_640.jpg


Then I drilled the hole out, mounted the plywood cover plate into position and ran a screw into the hole and marked the next screw hole in the same way.

Mark, Drill hole, mount plate - all holes with screws...and repeat until all 7 screw holes were done.

If I were to do it again I would dispense with the plywood and just use the actual cover plate.

Once that was done, I decided where I wanted the selector located - I moved it aft and inboard. Made the underplate to which the selector would be mounted:

Underplate_5_640.jpg


with nutplates so that it can be attached/unattached to the cover plate from the top:

Underplate_6_640.jpg



Then I cut the 2.75" hole in the cover plate so that the Andair selector label plate would fit, located the position of the 4 nutplates on the cover plate, and drilled those out and mounted the nutplates.

Assembled, the rig looks like this:

Assembled_Top_640.jpg


Assembled_Bottom_640.jpg


So then after an airplane test fit it was time to wash, Alumaprep, Alodine, prime and paint - all of which I'd never done before. Results:

Plates_Ready_640.jpg


Ok so now it's time for the 3 fuel lines.....
 
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followup

Thanks for the followup - looks like a good solution. One thing I noticed is that it looks like you can add a nutplate to the valve. Mine didn't have that, and it looks like a great idea.
 
Thanks for the followup - looks like a good solution. One thing I noticed is that it looks like you can add a nutplate to the valve. Mine didn't have that, and it looks like a great idea.

It would have been a great simplification of the design to mount nutplates on the valve itself.

I tried to get the squeezer in there and I managed to install the nutplates:

Nutplates_on_Selector_Top_640.jpg


Nutplates_on_Selector_Underside_640.jpg


It was necessary to remove the fitting on one side to get the squeezer square.

So I really didn't need the underplate. However I can still use what I have and just unscrew the three screws in order to remove the cover plate. Although that does require removing the handle on the selector, which is something of a pain in and of itself. So it's kind of a wash:

Either remove the 3 screws holding the selector to the cover plate and the selector handle or

Remove the 4 screws separating the underplate from the cover plate.

The former would allow as unfettered access to the selector fittings as one can get.

Should I have to make a new cover plate (hopefully that will not be necessary) I could eliminate the underplate.
 
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Ok just to close out this thread:

The new fuel selector, it's new cover plate, and new TSFlightlines flex fuel lines are in.

Like all projects this one incurred some mission creep. But I was able to keep it to a minimum.

Ok first we have the selector installed on a clear plastic cover plate so that I can see down into the cavity and make sure everything is set up nicely:

3_lines_connected_top_640.jpg


The new fuel line that goes to the right tank connection goes under the wire bundle - as you can see above - instead of over the bundle as it did in the previous installation.

To prevent any chafing I installed split rubber tubing on both the wire bundle and the fuel line:


chafing_gear_installed_640.jpg


Lastly I installed the selector with the new cover plate whose design is shown in Post @23:


Selector_Installed_640.jpg


Nice little project though squirming into the limited space in order to connect the line to the aux pump was"fun".

I need to lose some weight.

Fuel tank and line tests upcoming.....
 
Seat pan bracket screws?

Looks good. On mine I have screws for the seat ramp side bracket that don't seem to be on yours - was the seat pan done differently before or after my kit? Mine looks like the photo that PhatRV posted. Here's what I have:

Seat Ramp F-880B-L-1.png

Seat Ramp F-880-R.png
 
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Just a short follow up:

Ground testing of the fuel system is complete. Good flow; no leaks.

Ground engine testing completed: no leaks, good fuel delivery.
 
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