Re: '48 Fuel pump one way valve
Posted: Tue Jun 19, 2018 7:22 pm
Bruce, here’s the dimensions.
Gary, looks like Parker on the label to me.
Gary, looks like Parker on the label to me.
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Here's an accident report on a C-195 where a copper oil scavenge line failed. The Aussies are queasy about copper fuel lines too. Here's what John Schwaner says about copper tubing:n2582d wrote: ...Frankly, that copper fuel pressure line, restrictor or no restrictor, makes me a bit queasy. If the line breaks with no restrictor there is a stream of pressurized fuel in the vicinity of the red hot exhaust pipes. With a restrictor it's probably a fine mist of pressurized fuel. Too vivid of an imagination I guess. I have never heard of NTSB reports where this has been an issue. But I have had 1/8" fuel primer lines break. ...
Of course for those wanting to maintain the antique look of copper tubing aluminum lines just don't cut it. It would be easy to anodize these lines a copper color. Any metallurgists out there know how anodizing affects fatigue strength in aluminum?Most tubing-failures on aircraft are caused by fatigue. Tubing on aircraft vibrates. How well your tubing endures when subjected to load reversals, impulses, and vibration is called "fatigue strength". Of the three popular tubing types (3003-0, 6061-0, 5052-0), 5052-0 has the best fatigue strength. Originally aircraft used soft copper-tubing. There is even some of this still around. Although copper was strong enough, it was replaced with aluminum and stainless tube because of the high fatigue failures of copper. For lower pressures, 5052-0 became the tubing of choice because it has the best fatigue strength of any of the non heat-treat aluminum alloys. ... Copper tubing on older aircraft should be removed and replaced with 5052-0 before it breaks. There is no warning when copper tubing breaks. One cannot "inspect" it and declare it ok. Another limitation on the use of copper tubing in aircraft engine compartments is that copper strength decreases rapidly with temperature. Some experimental and light-sport aircraft have hydraulic and fuel lines built with 6061-0 or 3003-0-tubing. Low ultimate strength and low fatigue strength provide a narrow safety margin in dynamic (vibration or impulse) applications. Take extra care in clamping and preventing tube vibration. The aircraft industry's long experience with copper tubing failures proved the importance of fatigue strength. 5052-0 has higher strength and higher fatigue strength at a small price difference. Both 5052-0, 3003 have the same Cold Workability Rating of A (easy to work with). 6061-T6 has a far lower rating of C. "It hasn't failed yet," was the attitude at NASA that essentially led to both of the Space Shuttle disasters; the complacency arises from skirting the line and surviving. But the law of large numbers will eventually get you.