Maintenance of the Humphrey ADE-circle system (main body and soda lime canister).

Annual service:  With the very low fresh gas flows used by the ADE-circle system, it is vital that the system does not leak and that all valves work correctly. The main culprit for a failing system, besides actual physical damage, is soda lime dust which can get into all the components and reduce function. This maintenance section describes how to undertake the servicing safely and effectively, ensuring correct re-assembly.


The main body of the ADE system requires little maintenance though routine leak tests must be carried out every day on the whole system. The latter should not be omitted as leaks can occur at any time more often in tubing and reservoir bags. However it is the soda lime canister that requires more maintenance on an annual basis.  It has five seals which can become soft with time and allow leaks.  In addition the red and blue one-way valve flaps can also relax and allow incomplete closure with small reverse leaks; it is recommended that these are replaced annually.