Seeking information on use of 6161 T-6 for hydraulic lines (2000psi max service pressure). Can 6061 T-6 5/16 tubing be properly bent, and flared for AN-5 fittings without structural damage to the tubing wall? I am having difficulty sourcing -0 or T-4 tubing which I understand is malleable enough for bending and flaring. Can the ends and bend locations of the T-6 tubing be returned to -0 or -4 for forming?
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6061 T-6 hydraulic lines
- Thread starter rrayman
- Start date
TugboatEng
Marine/Ocean
The aircraft industry has decades of experience with aluminum hydraulic systems. I suggest looking there for guidance and materials.
I also suggest using flareless MS type fittings on hard tubing.
I also suggest using flareless MS type fittings on hard tubing.
We used all sorts of nasty acids for etching different materials when making ICs, but aluminum, meh, good old phosphoric acid, an ingredient of Coke.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
Suggest using 'aerospace hydraulic quality' 6061 tubing... not general purpose/older spec... drawn tubing.
The following tube-specs pass rigorous inspection/testing for this very purpose...
6061-T4 HYDRAULIC TUBING MIL-T-7081 or AMS-T-7081 or AMS4081
6061-T6 HYDRAULIC TUBING MIL-T-7081 or AMS-T-7081 or AMS4083
NOTES1.
A. System working pressure, proof-pressure [test] and burst-pressure [ultimate] requirement should be carefully evaluated for intended use... so Diameter-VS-[standardized] wall thickness has to be determined by YOU.
B. WW-T-700/6 and AMS4082 or AMS4080 or any commercial grade [ASTM, etc] drawn tubing... are also acceptable when carefully evaluated/tested... but these are made to older standards which are not optimized for applications where tight/quality-bending, single or double-flaring and swaging are required.
C. DRAWN or extruded/drawn Tubing... ONLY... never simply extruded tubing... should be used in fluid applications. Lotsa reasons.
There are several documents/manuals for aircraft quality tubing-assembly [tube selection, cutting/trimming/bending + flared and/or swaged end-fittings + corrosion protective finishes + inspections and proof-testing + installation + markings]...
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
BTW: 'AN-5 fluid fitting(s)' simply don't exist... no earthly idea what You are referring to.
There are however hundreds of different aerospace fluid-fitting types available.
I have a nicely illustrated catalog that is useful for-pick-n-choose... but it's too large a file to be up-loaded, in E-T. Other fluid-component document references are meaningless without access to the other documents it references.
Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
The following tube-specs pass rigorous inspection/testing for this very purpose...
6061-T4 HYDRAULIC TUBING MIL-T-7081 or AMS-T-7081 or AMS4081
6061-T6 HYDRAULIC TUBING MIL-T-7081 or AMS-T-7081 or AMS4083
NOTES1.
A. System working pressure, proof-pressure [test] and burst-pressure [ultimate] requirement should be carefully evaluated for intended use... so Diameter-VS-[standardized] wall thickness has to be determined by YOU.
B. WW-T-700/6 and AMS4082 or AMS4080 or any commercial grade [ASTM, etc] drawn tubing... are also acceptable when carefully evaluated/tested... but these are made to older standards which are not optimized for applications where tight/quality-bending, single or double-flaring and swaging are required.
C. DRAWN or extruded/drawn Tubing... ONLY... never simply extruded tubing... should be used in fluid applications. Lotsa reasons.
There are several documents/manuals for aircraft quality tubing-assembly [tube selection, cutting/trimming/bending + flared and/or swaged end-fittings + corrosion protective finishes + inspections and proof-testing + installation + markings]...
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
BTW: 'AN-5 fluid fitting(s)' simply don't exist... no earthly idea what You are referring to.
There are however hundreds of different aerospace fluid-fitting types available.
I have a nicely illustrated catalog that is useful for-pick-n-choose... but it's too large a file to be up-loaded, in E-T. Other fluid-component document references are meaningless without access to the other documents it references.
Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
EdStainless
Materials
There are also hydraulic tube specs in ASM for SS (304 and 21-6-9) at various strength levels, as well as for Ti 6-4.
In high strength 21-6-9 (150ksi UTS 125ksi Yld, >20 elong) they use 1" x 052" (1/2" x 028", 3/8" x 0.22") for 3,000 psi suffice. But SS has infinite fatigue life at this strength/stress.
The Ti tubing (and I would expect Al) have a very finite fatigue life. So great care need to exercise using them.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
In high strength 21-6-9 (150ksi UTS 125ksi Yld, >20 elong) they use 1" x 052" (1/2" x 028", 3/8" x 0.22") for 3,000 psi suffice. But SS has infinite fatigue life at this strength/stress.
The Ti tubing (and I would expect Al) have a very finite fatigue life. So great care need to exercise using them.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
TugboatEng
Marine/Ocean
SAE -5 and JIC -5 both exist. JIC shares dimensions with AN so that could be a source of confusion. -5 and -10 sizes are obsolete and should be avoided if possible.
Ed...
Per most documentation/tech data Ti-3Al-2.5V tubing for 3000-up-to-5000(+)-PSI service MUST be autofrettaged after forming and before swaging-on fittings. Pretty impressive process to pressurize the raw-formed-tubes to 12000-PSI for strain/stress relief. I happened to be in the shop where a line was being Autofrettaged... always in a safety-water-tank... when a it failed [blew-out]. Good thing it was pressurized with water... in-water!
As I understand-it, 21-6-9 tubing is sometimes autofrettaged for service above 3000-PSI... and/or for cases where pressure spikes are frequent.
Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
Per most documentation/tech data Ti-3Al-2.5V tubing for 3000-up-to-5000(+)-PSI service MUST be autofrettaged after forming and before swaging-on fittings. Pretty impressive process to pressurize the raw-formed-tubes to 12000-PSI for strain/stress relief. I happened to be in the shop where a line was being Autofrettaged... always in a safety-water-tank... when a it failed [blew-out]. Good thing it was pressurized with water... in-water!
As I understand-it, 21-6-9 tubing is sometimes autofrettaged for service above 3000-PSI... and/or for cases where pressure spikes are frequent.
Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
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