SCEET Hose Spec

[Stephan Nelle]

Is there a mil-spec or similar industry spec (AN, MS, NAS, AMS, ASTM, SAE, etc) that SCEET hose is made to that provides dimensional, material, and performance criteria? Like an AN960 washer spec sheet, but for SCEET hose.

The manufacturer of the SCEET hose that my company has been using for decades (Thermoid) is having quality problems that result in delaminations between the inner and outer silicone-impregnated fiberglass layers. We are seeing this on brand new, uninstalled hose straight from the manufacturer. We are of course in touch with them, and are also actively searching for an alternate manufacturer. The three manufacturers of SCEET hose that I am aware of (and am in touch with) are Thermoid, ITT (formerly ITC) and Venair (based in Spain). On none of the technical data sheets I have from any of these three companies is there reference to an industry spec.

I am looking for what the definition of SCEET is, i.e. is there a industry standard, or is it what each individual manufacturer wants it to be?

 

[WKTaylor]

I'm pretty sure what You are describing is embedded in one of the following...

AS1501 Hose, Air Duct, Flexible, Nonmetallic, Aircraft ... General spec for a family of air duct hoses and other 'good-to-know extra-stuff', thus...

AS1502 Hose, Air Duct, Flexible, Helical, Metallic Wire, Supported (Exposed), Self Extinguishing
AS1503 Hose, Air Duct, Flexible, Helical, Metallic Wire, Supported (Covered), Self Extinguishing
AS1504 Hose, Air Duct, Flexible, Helical, Nonmetallic Wire, Supported (Exposed), Self Extinguishing
AS1505 Hose, Air Duct, Flexible, Annular Convoluted, Self Extinguishing
AS1506 Hose, Air Duct, Semiflexible, Sleeve Section, Unreinforced, Self Extinguishing
AS1541 Hose, Air Duct, Flexible, Helical Convoluted, Metallic Wire Supported (Covered), Self Extinguishing
AS1542 Hose, Air Duct, Flexible, Helical Convoluted, Self Extinguishing
AS1543 Hose, Air Duct, Semiflexible, Sleeve Section Unreinforced, Self Extinguishing, Nomex
AS1544 Hose, Air Duct, Flexible, Helical, Nonmetallic Wire Supported (Covered), Silicone Rubber, Self Extinguishing
AS1591 Hose, Air Duct, Flexible, Polyurethane-Coated Fabric, 1 psi, External Nylon Helix, Self Extinguishing
AS4546 Hose, Air Duct, Flexible, Silicone Coated Fabric, 1 to -.5psi, External Nylon Helix, Self Extinguishing
AS4774 Hose, Air Duct, Flexible, Silicone-Coated Fabric, 1 psi, External Nylon Helix, Self Extinguishing
AS4804 Hose, Air Duct, Flexible, Silicone-Coated Fabric, External Nylon Helix, Low Noise

MIL-PRF-62028 HOSE, AIR DUCT: HIGH-TEMPERATURE FLEXIBLE, REINFORCED... this spec has both general and specific data for high temp flexible air duct hoses.

Regards, Wil Taylor
o Trust - But Verify!
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", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

 

[Stephan Nelle]

Wil, super! Thank you very much!

Now to request input from folks familiar with SCEET hose in the (aircraft) industry:

Have you seen similar delamination between the inner and outer layer?

Have you set up an inspection criteria to determine if the bond between the inner and outer layer is adequate, such as a peel-type test, or a subjective "tug" test? (I would love for us an an OEM airframer to not have to go to this length, but rather to be able to rely upon the C of C of the hose manufacturer for this, but the recent quality problem indicate there needs to be additional inspection requirements at our end to catch what the manufacturer did not catch).

Do you have a preferred manufacturer of SCEET hose based on experience and good quality? I am not affiliated with any of the hose manufacturers, but just want the best possible quality hose that is available.

 

[WKTaylor]

Follow the Acft Maintenance Manual [AMM] guidance... and/or I recommend installing these air ducts with great care... same as thin-wall [low pressure] fluid hoses installed/clamped over beaded tube-ends.

SAE ARP1658 Hose Assemblies, Installed, Visual Inspection Guide For
SAE AIR1569 Handling and Installation Practice for Aerospace Hose Assemblies
SAE AIR5386 Hose and Hose Assembly Selection, Installation, Inspection and Maintenance Guidelines, Listing of

Unsure of exactly what defects You are seeing.

I have seen the helical wires become loose and/or tear out or crimp... or the outer and inner jackets simply get old/tired in service checking-cracking-tearing... and of course abuse such as crushing or cutting/punctures [lock wire, screw-drivers, etc] or contact with incompatible fluids [oil, gasoline, etc] causing rubber deterioration.

Regards, Wil Taylor
o Trust - But Verify!
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", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov