An assembly for use in a turbocharger, the assembly comprising: a 3-way valve defining a primary through-passage and further defining a bypass passage that, when open, diverts a bypass flow of exhaust gases away from the primary through-passage; and a turbine housing for housing a turbine wheel, the turbine housing defining an exhaust gas inlet connected to a turbine volute configured to surround the turbine wheel, the turbine housing further defining an exhaust gas exit for discharging exhaust gases that have passed through the turbine wheel; wherein the valve includes a rotary element whose position is controllable to selectively open or close, and to vary a degree of opening or closing of, each of the primary through-passage and the bypass passage of the valve, and wherein the valve is constructed such that the rotary element is rotatable over a first range of rotary movement and over a further second range of rotary movement, the first range including a position of the rotary element in which the bypass passage is substantially fully closed, wherein over the second range the bypass passage is fully open regardless of changes in the degree of opening or closing of the primary through-passage, characterised in that: the valve includes a valve housing that is integral with the turbine housing, the valve housing comprising a Y-member having a first leg and having second and third legs ( L2, L3) that branch off from the first leg, the first leg being configured to be connected to an exhaust line through which exhaust gases are received from an engine, the second leg being connected to the primary through-passage of the valve, and the third leg being connected to the bypass passage of the valve; and the valve further comprises a fixed valve seat defining at least one orifice, and wherein the rotary element comprises a rotary valve member defining at least one orifice, the valve member and valve seat being disposed in the second leg of the Y-member, the valve member being disposed against the valve seat and being rotatable about an axis for selectively varying a degree of alignment between the respective orifices defined through each of the valve seat and valve member in order to regulate flow through the primary through-passage of the valve, and wherein the valve member comprises a blocker extending therefrom, the valve member being rotatable to a plurality of different positions, including at least: a phase 1 position, constituting an exhaust line-open/turbine-closed position in which the orifices in the valve seat and valve member are fully aligned thereby allowing flow through the primary through-passage, and in which the blocker is positioned to substantially prevent flow through the bypass passage into the turbine volute; and a phase 2 position, constituting an exhaust line-closed/turbine-open position in which the orifices in the valve seat and valve member are misaligned thereby substantially preventing flow through the primary through-passage, and in which the blocker is positioned to present no substantial impediment to flow through the bypass passage into the turbine volute. a 3-way valve defining a primary through-passage and further defining a bypass passage that, when open, diverts a bypass flow of exhaust gases away from the primary through-passage; and a turbine housing for housing a turbine wheel, the turbine housing defining an exhaust gas inlet connected to a turbine volute configured to surround the turbine wheel, the turbine housing further defining an exhaust gas exit for discharging exhaust gases that have passed through the turbine wheel; the valve includes a valve housing that is integral with the turbine housing, the valve housing comprising a Y-member having a first leg and having second and third legs ( L2, L3) that branch off from the first leg, the first leg being configured to be connected to an exhaust line through which exhaust gases are received from an engine, the second leg being connected to the primary through-passage of the valve, and the third leg being connected to the bypass passage of the valve; and the valve further comprises a fixed valve seat defining at least one orifice, and wherein the rotary element comprises a rotary valve member defining at least one orifice, the valve member and valve seat being disposed in the second leg of the Y-member, the valve member being disposed against the valve seat and being rotatable about an axis for selectively varying a degree of alignment between the respective orifices defined through each of the valve seat and valve member in order to regulate flow through the primary through-passage of the valve, a phase 1 position, constituting an exhaust line-open/turbine-closed position in which the orifices in the valve seat and valve member are fully aligned thereby allowing flow through the primary through-passage, and in which the blocker is positioned to substantially prevent flow through the bypass passage into the turbine volute; and a phase 2 position, constituting an exhaust line-closed/turbine-open position in which the orifices in the valve seat and valve member are misaligned thereby substantially preventing flow through the primary through-passage, and in which the blocker is positioned to present no substantial impediment to flow through the bypass passage into the turbine volute.