Lo-Flow trim is a general-purpose cage guided plug throttling style trim designed to handle very low Cv applications. It is intended for use with either compressible or non-compressible fluids where there is a moderate or low-pressure drop requirement.
The trim consists of a tapered plug that fits into a cage and seat with a matching taper in the bore of the seat ring. The angles of these tapers are small so that the flow area throughout the trim is essentially constant from inlet to outlet. This results in small changes in flow area with respect to plug travel, providing good turndown for a general-purpose valve.