Difference between MQ, VMQ, PMQ and FVMQ

Silicone rubber is known by several terms which can lead to misinterpretation. Firstly, the ISO (International Organisation for Standardisation) uses the abbreviations of MQ, VMQ, PMQ and FVMQ. Conversely, ASTM (American Society of Testing and Materials) uses its own designations of GE, FC, FE and FK. For this reason, we will explain the structural differences indicated by these terms and the unique properties they provide.

Silicone is the preferred material for use with food, medical and aerospace industries due to its great flexibility, thermal stability, low toxicity, resistance to oxygen, ozone and UV, as well resistance to microbiological growth. It offers the widest temperature range of all O-ring materials from -55°C to 200°C as standard, with specially compounded versions ranging from -115°C to +232°C.

Heat is one of the most destructive forces in compound deterioration. To decide which is the best high temperature O-ring, it is important to consider other factors such as the required chemical resistance. For high temperature applications (over 150°C) you may wish to consider using one of the following materials; FKM, FFKM, ACM, HNBR, VMQ, FVMQ, AFLAS, PTFE and FEP.