ABSTRACT
The accurate mathematical model of valve control hydraulic system with long pipeline is constructed
through theoretical analysis. The influences of long pipeline on valve control hydraulic system are
investigated. A series of conclusions were obtained, which are important to the design and analysis of valve control hydraulic system.

INTRODUCTION
Large-sized construction machinery usually has tens of actuators. All of them get power from a entral
hydraulic source. Some are far away from the hydraulic source. The long pipeline between actuator and hydraulic source is essential sometimes. It causes many problems to electro-hydraulic system. This paper studies the influences of long pipeline on valve control system and comes to some simply and valuable conclusions