Performance Requirements for Nonmetallic Air Brake System Tubing
This SAE Standard covers the minimum requirements for nonmetallic tubing as manufactured for use in air brake systems which tubing is different from that described in SAE J844. It is not intended to cover tubing for any portion of the system which operates continuously below - 40 degrees C or above +93 degrees C, above a maximum working gage pressure of 1.0 MPa, or in an area subject to attack by battery acid. This tubing is intended for use in the brake system for connections, which maintain a basically fixed relationship between components during vehicle operation. Coiled tube assemblies required for those installations where flexing occurs are covered by this document, SAE J1131 and SAE J2494-3, to the extent of setting minimum requirements on the essentially straight tube and tube fitting connections which are used in the construction of such assemblies.
Rationale: This new document is intended to be a descriptive envelope for Air Brake System Tubing, which eliminates the material requirements of SAE J844 but retains the technical requirements. The following new technical requirements are added: cutting, high temperature burst, tubing spring back (optional), high temperature deformation under pressure, thermal cycle pressurized, moisture saturation, oil resistance of tubing interior, and chemical resistance. The following J844 requirements were modified: manufacture, construction, dimensions and tolerances, mechanical properties, cold temperature impact, stiffness, cold temperature flexibility, heat aging, and ultraviolet resistance. The following J844 requirements were eliminated (moisture absorption).