in which the medium in one direction must flow through the throttling channel, and in the other direction may flow through a much wider channel parallel to the throttling channel

Full Title

Means in valves for absorbing fluid energy (for pipes F16L55/00) > for decreasing pressure and having a throttling member separate from the closure member > in which the medium in one direction must flow through the throttling channel, and in the other direction may flow through a much wider channel parallel to the throttling channel