Seal assemblies for use with fluid valves are described. An example apparatus includes a cage; a plug including a seal gland; and means for sealingly engaging an inner surface of the cage at least partially positioned in the seal gland and including a first portion and a second portion, in response to a fluid acting on the first portion in a first direction, the first portion to engage, outwardly urge, and splay the second portion to sealingly engage the cage, in response to the fluid acting in a second direction, the second portion to deter the fluid from acting on the first portion, the first direction opposite the second direction.