A device comprises: a container; a first fitting coupled to the container; and a second fitting coupled to the container, wherein the first fitting is configured for coupling to a first service port of a system and the second fitting is configured for coupling to a second service port of the system such that a fluid can travel from the first service port to the second service port through the container while the system is running, wherein the system comprises at least one of an air conditioning system or a refrigeration system.