Quick replacement air valve

An air valve apparatus for a tire rim including an external face defining a valve aperture with an aperture diameter, the assembly comprising:

• a valve stem with an inside and an outside, the outside including a neck extending from an external end including stem threads stopping above an unthreaded sliding portion adjacent to an internal end, the internal end including a smaller-than hole flange;
• a valve core mounted inside the valve stem;
• an elastic seal mounted on the outside of the valve stem between the smaller than hole flange and the stem threads, the elastic seal including a slider end positioned on the unthreaded sliding portion, a cylindrical inward arm, and an inward end;
• an exterior accessible nut engageable with the stem threads, wherein movement of the exterior accessible nut on the stem treads compresses the elastic seal between the slider end and the inward end to expand the elastic seal into engagement with the tire rim.