A flow conditioner of a valve assembly includes a body including a longitudinal axis, a first end, a second end, and a flow path connecting the first end and the second end. A non-planar surface is formed in the first end of the body. A plurality of channels define the flow path and extend parallel to the longitudinal axis. At least one channel of the plurality of channels has a length different from a length of an adjacent channel of the plurality of channels. A cylindrical housing surrounds the plurality of channels and includes a first end and a second end. The first end is proximally located to the first end of the body. The non-planar surface of the first end is defined in part by an end of the at least one channel of the plurality of channels.