Is it a multi section gear type divider?
Then the cartridge is likely a relief valve from outlet back to inlet to limit pressure intensification.
Since a gear divider transfers energy from one section to another, if there are one or more ports lightly loaded (due to light load, or a broken hose on that outlet) the pressure in the other outlet ports can rise to 4/3 or 3/2 or other ratios of increase. Pressure could get very high on the remaining outlet sections.
The differential relief valves on each port limit that possible rise by rleieving from outlet back to the common inlet.
search on Haldex Barnes, I know those have these RV built in. Parker gear dividers also I think.