A pressure control valve has: a passageway having a flow opening; an member displaceable relative to the opening for obstructing the opening by differing amounts; a piezo actuator; and a linkage mechanism adapted to amplify a dimensional change in the piezo actuator and to use the amplified dimensional change to displace the member relative to the opening, wherein the linkage mechanism comprises a frame attached to a wall and fixed at a first end in relation to the passageway, a portion of the frame moveable in a first direction while being substantially restrained in a second direction orthogonal to the first direction, the piezo actuator extending between the wall and the movable portion such that an expansion of the piezo actuator results in movement of the movable portion in the first direction by an amount greater than the expansion of the piezo actuator, the moveable portion connected to the member.