COMPONENT OPERATION / Travel Device Overload Relief Valve Circuit Protection Operation: 1. When pressure in the circuit increases over the set-pressure of overload relief valve, the poppet is opened and high pressure oil relieves to the low pressure side, so that the travel motor is protected from being overloaded. 2. In addition, the overload relief valve relieves the shock loads developed due to inertia force when stopping the travel motor. Overload Relief Valve Poppet Low Pressure T183-03-05-011 High Pressure T3-5-8