An injector for injecting a reagent includes an electromagnet and an axially translatable valve member positioned within a housing. The valve member is moveable from a seated position to an unseated position in response to energizing the electromagnet. The valve member includes a hollow tube including a curled end having a reduced diameter sized to allow a ball to partially extend beyond the tube end but not pass through the tube. The tube includes an inwardly extending detent restricting the ball from movement within the tube. A pintle head is fixed to the tube and positioned proximate the electromagnet.