The series of Kobelco Excavator SK330 hydraulic cartridge type adjustable pressure reducing valve is to reduce the pressure in one line of hydraulic system, maintain certain pipe line in a setting pressure than other pipes.
In the hydraulic system, a hydraulic pump is often needed for oil to several actuators. When the actuator working pressure is not the same that is needed to control separately.
Pressure reducing valve is open, when the load pressure (secondary pressure) when adjusting the pressure of the valve is not reached, heart valve in valve full open under spring force, oil flow all flows through the valve, the primary pressure almost equal. Only when the load pressure when it reaches the set pressure, valve spool closed is very small, vacuum control can be achieved. If one certain component needs lower pressure than the power pump supplying, one cartridge type adjustable pressure reducing valve can be amounted in series connection, all the pressure needed in this pipe will be supplied by the adjustable pressure reducing valve, the control circuit hydraulic system, clamp hydraulic system or lubricating oil often use pressure reducing valve.
The reducing valve is normally open, and when the load pressure (secondary pressure) does not reach the valve adjustment pressure, the spool will move and open the valve outlet port completely under the force of spring, all oil flow flowing through the pressure reducing valve port , one, two the secondary pressure is almost equal. Only when the load chamber pressure reaches the set pressure, valves' spool movement off small, so that the valve opening in order to achieve the pressure reduction control .
The reduce valve can be divided into two-way valves and three-way reduce valve:
Pressure reduce valve and a pressure of two-way communicating directly variable throttle valve (two-way pressure reducing valve with variable orifice to achieve decompression control conditions must flow through the variable orifice, this traffic load flow, leakage flow or pilot valve flow. The second orifice load by leaks such as gaps or pilot valve, taking into account the presence of the leak and the pilot valve flow, pressure reducing valve in the secondary pressure outlet output at zero flow, the valve is still working properly, and in imports once pressure changes secondary pressure remained unchanged.
Way pressure reducing valve by the two series variable orifice, two-way reduce valve, regardless of the intermediate load cavity flow through three-way pressure reducing valve can achieve decompression control. Way pressure reducing valve intermediate load cavity through a reverse flow, can maintain a constant load cavity pressure that both overflow function, which is also known as the overflow valve. Some way pressure reducing valve by a variable orifice and a fixed orifice in series, the throttle adjustment has applied in a pulse width modulation electro-hydraulic digital control valve.