An Automatic pressure valve for the inflation-deflation of pneumatic arrangements comprises a main body (102) with an inlet connector (103) communicated with a pressurized air supply network an outlet connector connected to a pneumatic arrangement and a mechanical means which allows for a total or partial air passage or blockage to perform inflation-deflation operations of the pneumatic arrangement in a faster and practical way. The mechanical means comprises a main movable plunger (116) having an inner stepped through channel (117), a spring (120) arranged on a seat (121) defined in the inner stepped channel (117), an inflation plunger (122) operatively retained by said spring (120), a proximal movable end (126) within a first inner chamber (105), a reduced middle section (119), and a distal movable end (128) having a smaller diameter than the proximal end (126) and arranged within a second inner chamber (106).