Interpretation ID: aiam1529
Alfred Teves GMBH
6 Frankfurt/Main 2
Postfach 119155
Germany;
Dear Mr. Beller:#This responds to your May 10, 1974, request fo permission to stamp label information on hose assemblies in place of banding, and to reduce S9.2.5 burst pressure from 350 to 100 psi, and your further request for an interpretation of the status of an inline check valve as part of a vacuum brake hose.#The inline check valve is not subject to Standard No. 106, *Brake hose*, as a brake hose end fitting. In this configuration, the couplers depicted in your drawing are the clamps, and the check valve is a separate component to which the hose assemblies are attached.#The issue of stamping instead of banding will be answered in our upcoming Notice 11 in response to petitions for reconsideration of the brake hose standard.#Your petition for a reduction in the burst strength requirement for vacuum hoses is denied. The minimum burst pressure of 350 psi was established by the Society of Automotive Engineers in 1942, taking into consideration the effects of backfire pressure and the severe underhood environment to which vacuum hose may be exposed. Hoses with this burst pressure have provided excellent reliability and durability. We have no data to justify a reduction in burst strength in view of the two hazards just cited.#Sincerely,Robert L. Carter,Associate Administrator,Motor Vehicle Programs;