Before going to the symbol of the valves, The switching position, flow direction, and port for different configurations are to be understood.
Arrow represents the flow direction
Closed position
Symbols for Direction Controlled Valves:
Two-way valves:
Two way, two position valves
Normally closed valves, P is not connected A normally, connected only when the valve is actuated
Normally open opsition, P is connected A. When the valve is not actuated the way is open.
Three-way valve:
Three ports, two position valves
Normally open position. P is not connected A normally, connected only when the valve is actuated
Normally open opsition, P is connected A. When the valve is not actuated the way is open.
Four-way valves:
Four way, Two position valves:
P is connected to A and B is connected to T
Second position P is connected to B and A is connected T.
Four way, Three position valve:
P,T,A,B
Mid position pump reticulating. P to T, A and B closed
H-Mid-position closed; P to A, B to T
Mid-position working line depressurized: P,A to B to T
P to A to B, T