A coil spring for use in a cavity, such as in a groove of a pin, a housing, or both. The cavity can also be part of a seal assembly. The coil spring can have a longitudinal component positioned within the plurality of interconnected coils that runs along the spring coil axis in order to increase rigidity of the coil spring. The longitudinal component applies a load against the coil spring and/or provides restriction against the coil spring taking a shape or size different than that of the coil spring retaining groove.

A nozzle cap spacer for a hydrant nozzle cap includes a spacer body defining an outer body edge, the spacer body defining a spacer body thickness; and a resilient first spacer spring arm extending from the outer body edge and biased away from the spacer body in an extended orientation, wherein the first spacer spring arm defines a first spring arm thickness; wherein the first spring arm thickness of the first spacer spring arm is equal to the spacer body thickness of the spacer body.

A fire hydrant assembly including a barrel having a top end, a bottom end, and a nozzle; and a nozzle cap assembly including a nozzle cap having a cap body, the cap body having a bore sidewall and an inner wall; and a nozzle cap spacer including a spacer body defining an outer body edge; and a resilient first spacer spring arm extending from the outer body edge and biased away from the spacer body in an extended orientation; wherein the nozzle cap assembly is secured to the nozzle such that the nozzle cap spacer is disposed between the inner wall of the nozzle cap and a distal end of the nozzle.