Do yourself a big favor and call Tom at TS flightlines. I'm on my second plane using all of his lines after butchering a bunch of tubing. After the investment in the tools to make the bends and flare equiptment it's not that much more in cost. His customer service is impecable!
Can you please direct us to a rig for high (really high) pressure testing, safely. My plan is install and test on the aircraft (on the ground of course) for leaks visually at service or working pressures (not max limit). I used my Google skills and found what one might consider for hose testing, a lower pressure leak test like this:Don't forget that you'll also want to build a rig to do high (really high) pressure testing, safely, of your lines after fabrication.
There is absolutely nothing wrong with a builder making his own hose assemblies. LOL, early on when I was just getting started on VAF, a certain famous member here told me he enjoyed making his own. Fair enough, then we did a price comparision and found that his time was more valuable than the effort to make his own assemblies, versus tested teflon ones. Including buying various styled hose ends to get the routing correct.
To answer Larry's post, finding conductive teflon hose from an industrial source is tough. Most 'race car' hose suppliers dont use it. Ours, -4 and larger when used for fuel and oil are conductive. Those for brake systems with a clear chafe cover are not-----brake fluid doesnt flow to make the brakes work, its compressed, so it doesnt pick up static electricity. Thus a conductive liner for brakes isnt necessary. High quality suppliers like Earls and Goodridge have excellent components for the builder that wants to do their own assemblies.
Pressure testing---slightly more involved than just a leak check at 120 PSI under water. You want to take it to the rated working pressure OF THE HOSE, then a safety margin, usually 2 times the working pressure. Before I spent the money on a large test bench (Hydraulic Technology, Inc) I had a hydraulic ram pump, gauge, and an old parts washer cabinet and made my own. MESSY is the operative word. Made a bunch of adapters for the different sizes. Served the purpose.
WE get calls all the time from builders that have made some assemblies and for one reason or another have issues. Its all part of the 'education and recreation' of building your own plane. Most of the time its because they cant test the assembly before installation, only then finding a problem. Steve and I have spent alot of time, effort and money to help builders, both experts and novices, and provide them with quality tested hose assemblies they can rely on. WE take this very seriously, as it should be.
NOT an infomercial, but we chose to not use a push lock hose and fitting assembly, but a reliable crimped fitting teflon assembly. Crimped fitting, because we can control the crimp OD due to possible manufacturers variances. A resuable hose end should be matched to the same manufacturers hose, because presumably they were engineered together. Over the years, we've seen variances in hose OD in even the same manufacturers hose. WE use TEFLON because of its fluid temperature rating, capatibility, and generally lighter weight as compared to rubber lined lines.
Again---nothing wrong with making your own hose assemblies. For those that chose not to, we are here to help.
Tom
for me they were much cheaper. how can a brick and mortar business hand you a finished product that costs no more than the ''raw materials''? i am not saying the service isn't worth it, but it costs more.that's the way it works.
To answer Larry's post, finding conductive teflon hose from an industrial source is tough. Most 'race car' hose suppliers dont use it. Ours, -4 and larger when used for fuel and oil are conductive. Those for brake systems with a clear chafe cover are not-----brake fluid doesnt flow to make the brakes work, its compressed, so it doesnt pick up static electricity. Thus a conductive liner for brakes isnt necessary. High quality suppliers like Earls and Goodridge have excellent components for the builder that wants to do their own assemblies.
for me they were much cheaper. how can a brick and mortar business hand you a finished product that costs no more than the ''raw materials''? i am not saying the service isn't worth it, but it costs more.that's the way it works.
Buying power..... but you’re probably right.
Never heard of conductive teflon hose.
What's it used for? Why?
So do Earls and Goodridge carry conductive Teflon hose or no?
Thanks,
Erich
So do Earls and Goodridge carry conductive Teflon hose or no?
Thanks,
Erich
And advantage of DIY is that tricky hose where you need to trial fit to get the length just right, and get the clocking on angled end-pieces just right (angled pieces on both ends).
I dislike swivel ends because they always seem to eventually get an oil film on them from a leak that's short of a drip.
I purchased my-6A that had been flying about 500 hrs. About 50 hrs later I was climbing out and began to smell fuel. Really smell fuel. Shortly later my feet started to feel wet. Checked under the panel and my fuel line going to the firewall was pissing a stream on my feet. Turned off the electrical boost pump, and the stream stopped. Now got worried that the engine driven pump would be sucking air. Declared a precautionary landing, and got on the ground ok with my shoes and carpet soaked in fuel. I had visions of my legs on fire before landing.
As it turns out, the builder decided to make his own using Earls parts. He misassembled the end fitting, and obviously never pressure tested it.
Flex lines must be pressure tested to pressures not likely available in your shop.
Ed,
......
What we do for these clocking or complicated fit issues is to send the customer the raw hose and fittings and let them do a mock up with the actual components. Once they are marked to the exact lengths and clocking, they come back to us for final assembly, pressure testing and shipment.
......
Steve
From this I'm assuming I could send you an old hose and say
"Please duplicate this" but better........................
Tom made my replacement hoses, for every flex line on my airplane.Dan,
We hear these kinds of stories often. Here is a video of a rubber lined hose failure. This hose had been in service for many years and developed a leak in the rubber liner. The owner was noticing fuel smells in the cabin. As soon as a little pressure was applied on the hydrostatic pressure test bench, it began to leak like a sieve. At the extremely low pressures it was normally under, it was only weeping slightly versus spewing fuel out.
https://www.youtube.com/watch?v=uu__Wt0ImLk&feature=emb_logo
I?ve fabricated fuel hoses in the past but would definitely not do it again. You really need to know what you?re doing when you fabricate your own fuel, oil or brake hoses. There are a lot of potential pitfalls and the consequences of a hose failure can certainly be fatal in a very ugly way. The trouble for many amateur builders who attempt to fabricate their own hoses is that they don?t know what they don?t know. This is definitely not the area of the build where you want to try and save a few dollars.
These recurring threads about DIY vs buying fabricated hoses should definitely have their own section in the “Never Ending Debates”.
I don’t want to take away from what I’m sure are very professionally made and tested hoses advertised here, but if you are interested doing it yourself, the fact is that you can make quality hoses on your own, easily and with normal shop tools. No Fear, Uncertainty and Doubt required.
As for the high test pressures, we test utility gas lines, steam lines, hydraulic lines and many other high pressure systems in the utility industry to ASME standards, which generally require hydro testing at 150% of the operating pressure. You can certainly test your lines at higher pressures, but you won’t be able to convince me that an oil system that is fully relieved by 100 psi needs to have hoses good for 10,000 psi. That’s a safety factor of 100. And then consider that nuclear power plant pressure systems are designed to a minimum safety factor of 2, with some as high as 5.
While you can have a confident feeling that your oil, gas and brake lines are tested to a certified standard, created back when fluid lines were all made of natural rubber - just know that it’s unnecessary. And it still won’t guarantee they won’t leak.
I test my lines using 150 psi compressed air, the earl’s test kit and a 5 gallon bucket. Works great.
BTW, if you buy the fittings and hoses from ANPlumbing, they’ll assemble them with crimps and test for you at essentially the price you pay for the materials. It’s a nice low cost option if you don’t want to do it yourself.
the ''untrained eye''. ok, so it was just a phone call to ANPlumbing to get specific recommendations for assemblies to be used in airplanes.
Ron,
Putting 150PSI of air pressure into a hose is no problem....UNLESS A FITTING FAILS. In that case, your day will get very interesting. There is a reason that hydrostatic tests are utilized when testing hoses under pressure.
While I'm sure you have a very nice test rig, it can be done safely at home as well.
The "at home" safe process is to fill the hose with fluid, for the quickest pressure relief, and then use a "Compressed Air Flow Safety Shut Off Valve" on the inlet to the test kit (search on that...about $30 device). One should probably have this handy device to prevent "whip lines" on a compressed air system anyway.
I use water, also in the water filled bucket, so if there is a failure the pressure relieves quickly. In the spirit of actually experimenting...I purposely partially assembled a fitting with only slight compression on a test hose. At 150 psi, the fitting did finally come off after waiting about 10 minutes, but it was a "pop" and that was it. My take-away was that the Earl's Speed Seal system is a pretty solid design.
And yes, I agree, the whole process should be about the "experience of building".
I personally enjoy doing the whole thing, from the big things like the airframe and engine, down to hoses and servos - all the way down to those little HD pins on the Garmin D-sub connectors. It's all part of the process of recreation and education.
Bob Noffs: not sure if you were being serious or not, but just in case... here's the link for AN8 hoses. Pick your ends and length...
AN Plumbing AN8 pre-made hoses
They say made in the USA and testet to 1000PSI... So please educate me where this would be worse than me learning to bend and flare solid lines for break lines? (they carry them in -6 and -4 also)
Also:
Since this topic is really interesting. How does ONE satisfy the "condition" of a Teflon SS braided hose? I mean lets say every year you look at them and from the outside they look the same. I assume this is the reason Cert. hose just get replaced every X years to be sure? What is the proper method to determine when the hose need to be replaced?
Since this topic is really interesting. How does ONE satisfy the "condition" of a Teflon SS braided hose? I mean lets say every year you look at them and from the outside they look the same. I assume this is the reason Cert. hose just get replaced every X years to be sure? What is the proper method to determine when the hose need to be replaced?
I use water, also in the water filled bucket, so if there is a failure the pressure relieves quickly. In the spirit of actually experimenting...I purposely partially assembled a fitting with only slight compression on a test hose. At 150 psi, the fitting did finally come off after waiting about 10 minutes, but it was a "pop" and that was it. My take-away was that the Earl's Speed Seal system is a pretty solid design.
And yes, I agree, the whole process should be about the "experience of building".
Pressure testing your hoses to only 150 psi is not best aviation practice and in fact it's very dangerous. It is recommended that hoses be tested to proof pressure for a good reason. But hey, it's the Experimental category so builders can do whatever they like.
When you test a hose to proof pressure you ensure that the end fittings are secured to a level that will preclude the possibility of the fittings failing under normal levels of vibration and flexing. Testing the hose to 150 psi does not provide that security. All you're doing is satisfying yourself that the actual operating pressure of the hose will not push the end fitting off....but it's not the actual operating pressure on fuel lines that represents the real threat....it's the vibration and movement of the flexible hose into the fixed end fitting.
Ron,
The link to the AN8 pre-made hoses is something completely different. We could absolutely build hoses with those components and sell them at that price, but we choose not to for a wide variety of reasons.