An apparatus can include a housing, a plunger configured to reciprocate along an axis within the housing, and an internal fluid chamber disposed in the housing. A valve, having a valve base and a deformable seal, can also be included in the apparatus. The apparatus can further include a seat having an aperture therein. The valve is configured to move into and out of contact with the seat when the plunger reciprocates within the housing, based upon a fluid pressure in the internal flow chamber. In addition, an outer diameter of the deformable seal of the valve is less than an outer diameter of the seat.