Service valve function: The service valve is a hydraulic valve that controls the flow of hydraulic fluid in the hydraulic circuit of the excavator. It is typically used to control the movement of the boom, stick, and bucket.
Negative relief valve function: The negative relief valve is a hydraulic valve that is designed to protect the hydraulic system from damage due to excessive pressure. It is typically used in the hydraulic circuit that controls the swing motion of the excavator.
Maximum pressure: The service valve and negative relief valve on the E200B excavator are capable of handling a maximum pressure of 35 MPa.
Opening pressure: The service valve has an opening pressure of 3.9 MPa, while the negative relief valve has an opening pressure of 1.6 MPa.
Flow rate: The service valve has a maximum flow rate of 160 liters per minute, while the negative relief valve has a maximum flow rate of 30 liters per minute.