INJECTOR METHOD OF SWITCHING BETWEEN INJECTION STATE AND DRAIN STATE

An injector is provided, comprising an injector body comprising an inlet passage configured to receive fluid, at least one injection outlet configured to deliver fluid, and a central bore, a needle valve disposed for reciprocal movement within the central bore between a closed position and an opened position; and an actuator configured to move the needle valve between the closed position wherein a first portion of a surface of the valve tip engages a first portion of a surface of the injector body to form a first seal that inhibits flow through the at least one injection outlet, and the opened position wherein a second portion of the surface of the valve tip engages a second portion of the surface of the injector body to form a second seal that inhibits flow through the drain outlet.