Mocal Oil sandwich plate. Oil tree check valve > Is there one?<

Does the oil tree have a check valve that will stop oil returning back to the pump and pick up from the oil filter? I know there is one in the oil tree for the oil cooler. Reason is i have installed the accusump to a good quality sandwich plate but there needs to be a check valve to stop it from returning the wrong way back into the sump, it needs to route straight through the block and to the bearings, i know this will be pressurising the filter but it will work just fine as long as there is a check valve.