---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 06/29/20: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:34 AM - Teflon fuel line (Michael Townley) 2. 06:40 AM - Re: WireViz (prestonkavanagh) 3. 06:44 AM - Re: Teflon fuel line (Charlie England) 4. 07:00 AM - Re: Teflon fuel line (user9253) 5. 06:48 PM - Re: Teflon fuel line (johnbright) ________________________________ Message 1 _____________________________________ Time: 01:34:13 AM PST US From: Michael Townley Subject: AeroElectric-List: Teflon fuel line Hi -This is my first question for the forum. I may use a Teflon fuel pipe with anodized AN fittings in an RV9 between the fuel tank and the Andair fuel selector. The anodized fittings don =99t seem to conduct electricity (even though the teflon fuel line has a metal-braid covered inside a plastic covering). I wondered whether this will be a problem/danger due to possible electrostatic charge from the flowing fuel. Thanks for any suggestions Michael Townley -- Mike Townley 0419393470 ________________________________ Message 2 _____________________________________ Time: 06:40:15 AM PST US Subject: AeroElectric-List: Re: WireViz From: "prestonkavanagh" "I used LibreOffice Draw to make my wiring diagrams. It worked but was pretty time-consuming." IF WireViz is the new best choice for documenting cables, what's the choice for the schematics? I want to add details to a Z101 foundation. Absent software it will be pencil lines on a paper printout, and that's well short of the standard. What is the recommended software? Recognize that for me this is rare and occasional use - I'll give up some functionality for drag and drop simplicity. Regards, PK -------- PBK3 PA-12, BD-4, RV6a, gliders Read this topic online here: http://forums.matronics.com/viewtopic.php?p=497078#497078 ________________________________ Message 3 _____________________________________ Time: 06:44:55 AM PST US From: Charlie England Subject: Re: AeroElectric-List: Teflon fuel line On Mon, Jun 29, 2020 at 3:38 AM Michael Townley wrote: > Hi -This is my first question for the forum. > > I may use a Teflon fuel pipe with anodized AN fittings in an RV9 between > the fuel tank and the Andair fuel selector. The anodized fittings don =99t > seem to conduct electricity (even though the teflon fuel line has a > metal-braid covered inside a plastic covering). I wondered whether this > will be a problem/danger due to possible electrostatic charge from the > flowing fuel. > > Thanks for any suggestions > Michael Townley > > -- > Mike Townley 0419393470 > Interesting question. When Teflon lined hose 1st came on the market, there were significant issues with static buildup due to flow in the non-conductive hose. Because of that, I suspect that you can't even buy Teflon lined hose these days without carbon impregnated Teflon used as the liner. So, while I can't answer your question with authority, I don't worry about it in my installation, since the carbon impregnated Teflon provides a static bleed connection along all components in the fuel system, keeping all the fuel at the same electrical potential. Thinking about it, if the anodized fittings were a problem, then you'd have the same issue even with aluminum 'hard line', because every joint would be an electrical break in the path. (The male taper of the fitting would insulate from the aluminum female on the tubing.) The old 'rubber' hoses likely had carbon in the liner too, and we never heard about static issues due to anodized aluminum fittings. Shucks, even the anodized fittings may bleed off the static charge, even though they seem to check as open on an ohm meter. 'Static straps' are usually quite high in resistance, so they don't provide a low voltage current path to ground (think about the danger if you're wearing a wrist strap & touch the wrong thing in a circuit.... https://en.wikipedia.org/wiki/Antistatic_device#:~:text=Antistatic%20mat, -An%20antistatic%20floor&text=Typical%20resistance%20is%20on%20the,line%2 0in%20an%20electrical%20outlet. I'd suggest checking with your vendor, to be sure that the hose you're planning to use has a carbon impregnated Teflon liner. FWIW, Charlie Virus-free. www.avast.com <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> ________________________________ Message 4 _____________________________________ Time: 07:00:24 AM PST US Subject: AeroElectric-List: Re: Teflon fuel line From: "user9253" No danger from static for a couple of reasons. Fuel can only ignite if it is mixed with oxygen (air). Since the fuel line does not contain air, it can not ignite. And even if there is air in the fuel line, the ratio of fuel to air needs to be within a certain range to ignite. The mixture will be too rich. Even if the fuel air ratio is ideal for combustion, there is still no need to worry. A metal airplane like your RV-9 will keep all parts of the fuel system at the same voltage. No sparks will jump. Some fuel systems use non-conductive rubber hose. In that case, the danger is not from static, but from mechanical damage or kinking. Anodized metal fittings might not be good conductors of electricity, but will conduct enough to prevent high voltages from building up. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=497080#497080 ________________________________ Message 5 _____________________________________ Time: 06:48:42 PM PST US Subject: AeroElectric-List: Re: Teflon fuel line From: "johnbright" mtown52(at)gmail.com wrote: > ... I may use a Teflon fuel pipe with anodized AN fittings... between the fuel tank and the... fuel selector... I wondered whether this will be a problem/danger due to possible electrostatic charge from the flowing fuel. > > Michael Townley > Teflon should have an additive to make it conductive else the flow of a non-conductive medium, like gasoline, will generate an electrostatic charge that will punch holes in the Teflon over time. Rubber hoses are naturally conductive enough and brake lines don't have flow. BTW I have the impression -3 hoses are not available conductive because they are used for brake lines and there is no flow. Tom Swearengen is an expert you could ask. https://www.tsflightlines.com/about-us.html -------- John Bright, RV-6A, at FWF, O-360 Z-101 single batt dual alt SDS EM-5-F. john_s_bright@yahoo.com, Newport News, Va https://drive.google.com/drive/folders/1u6GeZo6pmBWsKykLNVQMvu4o1VEVyP4K Read this topic online here: http://forums.matronics.com/viewtopic.php?p=497086#497086 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.