Hydraulic balance valve Excavator hydraulic cylinder valve core RDDA-LEN

First, why do we need pilot relief valves?
1, as a stable system pressure relief valve function, due to the direct-acting relief valve opening and closing characteristics (pressure flow characteristics) is relatively poor, especially when the flow specification is large, so the first reason is to adapt to the increase of flow specifications; The advantages are more stable pressure, good opening and closing characteristics, small pressure loss, etc. The corresponding disadvantage is that the speed of the action is worse than the direct action type, which is not suitable for use as a safety valve;
2, in order to facilitate the realization of electronic unloading, multistage pressure control, remote control and other functions;
Second, the function of direct acting relief valve
1, direct acting relief valve is often considered only suitable for low pressure and small flow. Suitable for small flow is right, low overwhelming is not necessarily, the main role of high pressure pilot relief valve is direct acting relief valve;
2, the direct-acting relief valve is often only considered to be the pilot stage of the pilot pressure valve (relief valve, sequence valve, pressure reducing valve, etc.), not paying attention to it is the preferred structure of the fast-acting safety valve, in fact, the safety valve of some important equipment, the flow is very large! Here the main consideration of speediness, basically do not consider the opening and closing characteristics, the key is to ensure safety!