Simon.
Secondary luboil system.
Next step is the secondary luboil system as indicated on the sketch below. From the luboilpump pressure side oil passes a discharge checkvalve "b" to the cooler. The cooler has a ventpipe with a valve " l" for venting, the pipe is connected to the drain ( yellow). After the cooler is a selector cock "c1" enabling a crossover connection to stb/port engine. Further before the pressure reductionvalve 3>1,5 kg/cm2 is a branch off to the governor servomotor for the fuelrack, the servo motor needs higher pressure than the enginelubrication, after the servomotor to drain as previously discussed.
Tore