Fuel Filter Question

[Tumper]

I have a question about fuel filters. In the RV?s I have seen (at least RV-6, 7 and 9?s) there is a fuel filter between the fuel tank and fuel selector valve. The filter is normally located just in front of the pilot and passenger seats (one on each side). In the planes I have seen this filter is plastic and connected with hose clamps to a short section of rubber fuel line that in turn connects to the aluminum fuel line. This filter is located before the fuel selector valve and fuel pump. Is this filter even needed? I don?t think Van?s pictures it.

I don?t think I am too paranoid but I don?t like the idea of hose clamps and rubber hoses carrying fuel in the cabin under my legs. Is there a better option? One aircraft supply company sells metal filters at $78.00 each. Thanks for the help.

[L.Adamson]

I have a filter in front of each seat. I didn't install these, until I installed a fuel totalizer, in which filtering is recommended. Before that, it was just a gascolator on the front of the firewall.

My filters are blue anodized aluminum with flare fittings. No rubber & no clamps. These are from a automotive racing company, but I don't have the model numbers on hand. I'll try to find them, if someone doesn't beat me to it.

L.Adamson --- RV6A

[terrye]

I am planning to incorporate an Andair GAS375 gascolator in each wing root for my RV-9A with injection. The system will be: Fuel tank - gascolator - boost pump - engine driven pump - injection system.

The gascolator has a built in cleanable and inspectable filter element. It has a push-in drain valve for preflight checking of fuel. It is of metal construction with AN fittings on the inlet and outlet and as mentioned it will be located outside the cabin.

Andair also makes some metal inline cleanable filters with AN fittings. I chose the gascolator since I would prefer to check the fuel preflight.

There are other manufacturers of metal filters, but I think Andair is one of the best.

[AltonD]

I see you are going with fuel injection. There is a rather large (and expensive) filter with the fuel pump install kit from Vans for the fuel injected engines. The gold object is the filter.

[Walt]

Originally Posted by Tumper

In the planes I have seen this filter is plastic and connected with hose clamps to a short section of rubber fuel line that in turn connects to the aluminum fuel line. This filter is located before the fuel selector valve and fuel pump. Is this filter even needed? I don?t think Van?s pictures it.

I don?t think I am too paranoid but I don?t like the idea of hose clamps and rubber hoses carrying fuel in the cabin under my legs. Is there a better option? One aircraft supply company sells metal filters at $78.00 each. Thanks for the help.

Plastic (or glass) filters with hose clamps have no business in a ailrplane, you should use a good quality all metal filter with SS pleated filter material and AN style end caps. The one I use (which is very similar to the one above from AFP) is the Flowezy 3ILA with 74 micron filter.

[C-GRVT]

Anyone planning or running gascolator(s) in the wing root(s), any thoughts as to the need or advisability of having a shutoff valve between the tank and gascolator? In the scheme that Terry proposes, without a shut off valve would not the tank have to be drained in order to check the gascolator bowl for debris etc.?
Bill Brooks
Ottawa, Canada
RV-6A finishing kit

[terrye]

Alton,
Andair sells a similar boost pump/filter combination and I corresponded with them about it. I don't like the idea of having to remove the filter and probably spill fuel in the cabin during annual inspections or to check/clean the filter. Also if the single filter ever clogs, the engine stops unless you have a bypass. If this happens you should also have a clogged filter indication. So I decided on the wing root location.

Bill,
I also discussed the fuel draining out the gascolator during servicing with Andair. They recognized it as an issue and recommended servicing with the tanks half full (say after a flight) and/or temporarily blocking the fuel vent (don't forget to unblock it!). I considered a fuel shutoff valve, for example a 3/8" ball valve, but I thought the risk of inadvertently leaving it in the OFF position was too high. If you go this route, drill a hole in the handle and safety wire the valve in the ON position before closing up the wing root.

I would prefer only a single gascolator ahead of the firewall (cost/weight), but Andair wants to protect the boost pump from contamination and the firewall location is downstream of the boost pump. So I decided on a gascolator in each wing root. This way each tank has their own filter/sediment bowl upstream of the selector valve and boost pump.

[schristo@mac.com]

i went with gasolators in each wing root... using them as filters that are easy to access and provide protection of the boost pump. fitting them was not terribly problematic but does involve making a mount and dealing with the tubing in a restricted space. ultimately i had to use a couple of speciality hoses and fittings from bonaco on the left side. the wing root fairing also needs to accommodate access for the fuel drain.

here are a couple of shots during the final piping installation...

left wing with a regular fuel pickup.


right wing with a flop tube.

[mlwynn]

Gee Steve,

That is really an elegant solution. I have a fuel filter in the bottom of my fuselage, just before the booster pump. I have been scratching my head about how to clean that without getting fuel all over the interior. This is a much better solution to the problem.

Do you think there will be any problem with resistance to fuel flow?

Regards,

Michael Wynn
RV 8 Finishing
San Ramon,CA

[gasman]

Stephen, What is your plan to shut off the fuel to service the units?