Fuel Systems

MERL offers a range of test and analysis services to support the increasingly demanding requirements for minimising fuel emissions from components and systems that utilise polymeric materials. These fuels include conventional hydrocarbons, hydrogen and other alternatives.

Polymeric materials are used in the transportation, storage and handling of liquid and gaseous fuels as hoses, pipes, linings, seals, tanks, etc. Key performance requirements that can be assessed include:

Rate of fuel emission due to ongoing low level permeation in components

Leakage conditions for seals subject to mechanical loading, thermal changes and fluid absorption resulting in stress relaxation, set and wear

Permeation testing
Transmission and absorption tests are used to quantify rates of permeation through materials and components and enable measurement of inherent material properties such as the coefficients of permeation, diffusion and solubility, Tests can also be performed to Corporate standards or dedicated tests developed to replicate particular service conditions.

Micro-SHED Testing
The micro-SHED test facility constructed at MERL has been designed to measure hydrocarbon emissions from components in a way that is comparable with regulated measurements by Sealed Housing for Evaporative Determination (SHED), but on a smaller scale. For more information on MERL's microSHED facility please click here.

Seal performance testing
Standard tests and specialist rigs have been developed to assess seal performance and identify potential leakage conditions e.g. due to low temperature transients. Accurate measurement of the relaxation in sealing force is used to assess performance and to compare designs and materials.

Prediction of emission performance
To assist with visualization and determination of non-equilibrium gas diffusion situations, MERL can perform Finite Element Analysis which enables the modelling of component geometries. The code has been used to investigate the effect of external metallic pressure windings on the permeation of gas through flexible thermoplastic pipe, and also to study the influence of thermal gradients on diffusion.

Relevant publication
Polymers to Resist Automotive Fuel Permeation and Emissions - Compatibility and Orientation Effects of Polymers and Multi-component Fuels. N Dale, G Morgan and R Campion, Proceedings of HPE 2002.