There is a study that was performed by (I think the University of Georgia) to test the different lengths of various size conduits for grounding purposes. The results list the lengths that would be good for different size conduits for grounding.
The conduit bodies that you have pictured, if made wrench tight would satisfy me for grounding/bonding purposes. IF they are wrench tight, either the threads are tight, or the conduit is tight against the shoulder of the conduit body.
When installing long runs of conduit, there are maximum lengths, when the grounding effectiveness of the conduit will no longer be effective.
Pierre
