scope:

This specification covers requirements for the material, construction, dimensions, quality, leakage, installation, design guidance, source approval and quality control, for both types of bellows. TYPE I is meant to be used in high temperature applications as the liner insulates the bellows from the exhaust gas heat, or to act as a dual wall pipe to insulate surrounding components from the exhaust heat.

TYPE I - Bellows with inner liner TYPE II - Bellows only

Additional qualifiers: A & B to provide additional protection from stones or other debris.

A is with no additional outer protective shielding/mesh

B is with additional outer protective shielding/mesh

Restricted Chemical Substances

All product supplied to the requirements of this specification must comply with the requirements of the MPAPS B-50 specification.

APPLICATION

This specification covers two types of bellows (flexible steel pipe) used for making connections between pipes used in the exhaust system. Each application needs to be developed on a case by case basis due to the differences in displacement and/or vibrations in the different vehicle/application/location. The bellows described in this document is to be used when raw fuel is present in the exhaust gas traveling through the piping, or when spiral wound flex (MPAPS F-1050) cannot meet the leak rate required by the engine/after-treatment provider. Spiral wound flex per MPAPS F-1050 may be used if it is after the treatment areas (DOC, DPF, SCR) of the exhaust system or there is no raw fuel or other reactant present in the exhaust gas at that point.