This standard covers the material requirements of engine tubes that are exposed to exhaust gas condensate and positive crankcase and ventilation, also known as vent and blow-by hoses, for use in automotive systems. Material properties are suitable for low vacuum and pressure tubes not requiring reinforcement, but reinforced hoses can as well be used and are part of this specification. Material properties are also suitable for vacuum hoses. No resistance tests to crank-case ventilation gases per GMW17227 are required for vacuum hoses. 

Material Description. Materials covered by this specification are divided into several Types and Classes, depending on construction and temperature capability. See Table 1. Hoses are defined by the Construction and Temperature capability.

Hoses are either suitable for applications subjected to maximum continuous operation temperatures of +150 °C with intermittent operation at temperatures up to +175 °C maximum, to maximum continuous operation temperatures of +175 °C with intermittent operation at temperatures up to +200 °C maximum, or for applications subjected to maximum continuous operation temperatures of +200 °C with intermittent operation at temperatures up to +225 °C, dependent on the Temperature Rating of the hose. The designation for the blow-by hose is defined as GMW17391 Type VWYZ, where V defines the construction of the hose, W defines the temperature capability of the hose, Y defines reinforcement, and Z defines the requirements for GMW17227 qualifications.

• Suffix Code Z for requiring GMMW17227 is xxxx1; if no resistance is needed, xxx2.
• If no suffix is given, suffix A shall apply. 
• Detailed overview of all types are shown in Table 1.

Note: Continuous and Excursion temperature limits are defined in the Vehicle Technical Specifications (VTS). The cold resistance test for all types of hoses is defined at -30 °C, however, hoses will be able to operate at -40 °C as soon as they are immersed with oil and blow-by in the engine.

Symbols. Not applicable. 

Applicability. For all elastomeric tubes and hoses exposed to Positive Crankcase Ventilation (PCV), Exhaust Gas Recirculation (EGR) gases, and vacuum tubes/hoses.