Various embodiments are directed to a modular valve apparatus. The modular valve apparatus includes a retaining component having an opening on either end. The modular valve apparatus further includes a cap component having a hole bored through. The cap component may be adapted to be coupled with the retaining component. A generally annular spring component may be disposed within the retaining component and seated on a lower end extending axially toward an upper end of the retaining component. A check ball may be disposed within the retaining component and seated on the spring component. The check ball may be adapted to block the opening bored through the cap component while being held in place by the spring component.