Apparatus and associated methods relate to a solenoid assisted valve including a split collar and a precision sealing valve seat surface with tight dimensional tolerances and substantial performance repeatability. In an illustrative example, the split collar may concentrically mate around a cylindrical bobbin. In some examples, the split collar may include ferromagnetic material alone or in combination with various thermoplastic materials. The placement of the split collar may be adjusted by manufacturing to fine tune placement of a magnetic pole and to customize valve performance, for example. The valve seat may include, for example, an orifice sealed with an elastic stopper. The valve seat may be configured, for example, with specific ratiometric dimensional relationships and flatness specifications. Various solenoid valves may allow manufacturers to tune the location of a solenoid generated magnetic pole, for example, to tailor the valve plunger performance for a wide variety of applications.