Sequence valve works it?

Sequence valve works it?
How it works:
According to the working principle and structure, sequence valve direct-acting and pilot sub-type categories; by pressure control mode, the sequence valve has internal and external control of the points. In the sequence valve installed in a one-way valve, can be called a reverse flow check valve composite sequence valve. Generally, the valve use more.
Functions and applications:
The basic function is to control the sequence hydraulic valve block actuators multiple sequential actions, depending on their functions, called sequence valve, back pressure valves, relief valves and balancing valves. Relief sequence valve performance and essentially the same, but because of the different functions of the sequence valve as well as its special requirements:
(1) In order to achieve accurate actuator action sequence, the order requires high precision pressure regulator valve, the deviation is small;
(2) the accuracy of the order of actions in order to require a small amount of leakage within the aluminium valves is closed;
(3) For one-way sequence valve, pressure loss and requires reverse positive pressure loss values should be compared with the school
       The main role of sequence valve are:
(1) controlling the operation sequence of the plurality of elements;
(2) for packing loop;
(3) to prevent the weight of the free-fall and cause cylinder piston do with balancing valves;
(4) with external control sequence valves do unloading valves, pump unloading;
(5) with internal sequence valve for back pressure valve.