Interpretation ID: nht76-1.17

DATE: 07/01/76

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Parker Hannifin Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your March 24, 1976, letter concerning the application of the labeling requirements of Federal Motor Vehicle Safety Standard No. 106-74, Brake Hoses, to thermoplastic tubing of 1/8 inch nominal outside diameter that is used in "auxiliary air equipment rather than the brake system itself."

You have pointed out that it is difficult to label tubing of this diameter with letters that are 1/8 inch high, and requested an amendment of the standard to permit the labeling of such brake hoses with letters that are 1/16 inch high.

Because the tubing that you have described is not manufactured for use in the brake system itself, it is not "brake hose" as that term is defined in Standard No. 106-74 and is therefore not subject to any of the standard's requirements. In fact, although the standard does not prohibit the manufacture of air brake hose of 1/8-inch outer diameter, we are unaware at this time of the existence of any hose or tubing of that diameter that meets the definition of "brake hose". Therefore, the conformity or nonconformity of the tubing in question with the performance or labeling requirements of the standard is a matter of private contract between Parker Hannifin Corporation and those truck manufacturers that are requesting conformity.

In consideration of the possibility that 1/8-inch outer diameter tubing may in the future be used in brake systems, however, the NHTSA has decided to grant your petition to reduce to 1/16 inch the minimum required lettering height on brake hoses of such diameter. Accordingly, a proceeding respecting the issuance of a notice of proposed rulemaking has been commenced.

You should understand that our commencement of a rulemaking proceeding does not signify that the requested amendment will necessarily be issued. A final decision concerning the issuance of a proposal to amend the standard will be made on the basis of all available information developed in the course of the proceeding, in accordance with statutory criteria.

Sincerely,

ATTACH.

PARKER HANNIFIN CORPORATION

M. Schwimmer -- National Highway Traffic Safety Administration

March 24, 1976

Subject: CFR 571, STANDARD 106 SECTIONS 5.2.2 and 7.2 "MARKING"

Gentlemen:

As presently constituted, FMVSS 106 requires that the Department of Transportation marking shall be a minimum of 1/8" high. Note specifically Sections 5.2.2, 5.2.2 (a), 5.2.2 (b), 5.2.2 (c), 5.2.2 (d), and 7.2 We have determined that legible marking of this height cannot be printed efficiently by existing production equipment upon thermoplastic tubing of 1/8" nominal outside diameter. This height of letter would cover a total span of 114.5 degrees if in perfect alignment. Even with a grooved marking wheel, we have established that 60 degrees is the practical upper limit for the lettering height to span. Beyond this span, the skewed movement between type and its own printing at the top and bottom of each letter causes perceptible smudging, so that the printing actually becomes less readable instead of more so.

Major usage of 1/8" nominal outside diameter thermoplastic tubing on highway trucks seems to be in auxiliary air equipment rather than the brake system itself. Nevertheless, the truck manufacturers have required that this size conform to FMVSS 106 for safety reasons. If a complete failure of these lines should occur, they reason that the volume of compressed air supply momentarily lost could create a significant adverse effect upon the brake system. Not holding this size to the same requirements as all others would thus be inconsistent with the stated purpose of FMVSS 106:

"To reduce deaths and injuries occurring as a result of brake system failure from pressure . . . lost due to hose or hose assembly rupture."

We wish to make the following two alternative petitions in this regard:

1. We petition that the minimum lettering height of required marking on 1/8" nominal outside diameter airbrake tubing be changed from 1/8" to 1/16".

2. In the event that it is determined that the usage of 1/8" nominal outside diameter airbrake tubing lies beyond the scope of FMVSS 106, we petition for a clear directive which excludes this size from the standard and requires that it must not bear the marking called out in the sections of the standard which are referenced above.

Very truly yours,

W. E. Currie -- Chief Engineer

cc: W. Hertel; C. Foote; T. Landy