Testing elastomeric materials in liquified gases

To ensure safe and reliable products, elastomeric sealing materials in refrigeration systems and heat pumps have to be tested for their compatibility with refrigerants. The test method described in ISO 14903 and ISO 21922 covers aging in liquid refrigerant including a test in “wet” and “dry” condition. As part of a project to investigate the in-situ swelling behaviour of elastomers, the performance of elastomeric materials in liquid refrigerants was studied. The investigation focused on the behaviour of the materials during and after decompression in the autoclave. The data clearly indicate that the test description in the above-mentioned standards does not ensure a comparable test procedure or comparable results.