Relief valve with check function

A relief valve with a check function of relieving hydraulic fluid from a first port to a second port, the relief valve with a check function comprising:

• a housing having a body, and an adjustment member provided to be capable of advancing and retracting with respect to the body;
• a seat member provided in the body, the seat member being formed with a relief passage connecting to each of the first port and the second port;
• a relief valve body that is unseated from or seated on the seat member to open or close the relief passage, the relief valve body receiving pressure of the first port in a direction of opening the relief passage;
• a first biasing member that biases the relief valve body against the pressure of the first port, with a biasing force being adjusted by advance or retraction of the adjustment member;
• a check valve body that opens or closes a check passage connecting to each of the first port and the second port, the check valve body receiving pressure of the second port in a direction of opening the check passage;
• and
• a second biasing member that biases the check valve body against the pressure of the second port.