Flow restrictor assemblies including a monolithic flow restrictor and methods for manufacturing the same are provided. The monolithic flow restrictor is configured for disposing in a fluid passage of a housing body. The monolithic flow restrictor comprises a first end and a second end, a first screen at the first end and a second screen at the second end, and a series of cross-sectional portions between the first screen and the second screen. Each cross-sectional portion has a plurality of slots formed in a radially outer surface thereof for connecting a series of restricting orifices formed in the monolithic flow restrictor for tortuously conducting a fluid through the series of cross-sectional portions.

A throttle for a liquid pipe has at least one liquid duct for a liquid flowing through the throttle, the liquid duct extending along the longitudinal axis of the throttle. The liquid duct has at least one duct wall having a curved shape along the longitudinal axis.