This guidance note provides direction on the different methods used to manage oil in ammonia refrigeration systems.
It supersedes guidance note GN17 which has been withdrawn. In this guidance note the term ‘oil’ is used to cover a range of lubricants including mineral oil, synthetic oil, processed mineral oil (for example, hydrocracked oil) and other synthetic compounds such as alkyl benzene, polyalkyl glycol, polyol ester and polyalfaolefin. Not all of these synthetic compounds are compatible with ammonia.
Oil management on the low-pressure side of ammonia systems is necessary to keep the evaporators in good working order and to maintain system efficiency. The type of facility provided for the removal of oil from the low-pressure side of the system depends on the type of system, the type of oil, the level of manual intervention expected by the end user and the capital cost constraint on the installation.