A valve, comprising: a valve body having a fluid flow path extending therethrough; a valve seat located in the valve body; a disc located in the fluid flow path of the valve body, the disc rotatable between a first position and a second position about an axis substantially perpendicular to a longitudinal axis of the disc, the disc translatable between the second position and a third position in a direction substantially parallel to the longitudinal axis of the disc; and an actuation unit operatively coupled to the disc, wherein the actuation unit comprises a piston, a shaft of the piston extending within the fluid flow path of the valve body, wherein the actuation unit further comprises a spring element operatively coupled to the shaft and the disc, the spring element imposing a biasing force on the disc in a direction away from the valve seat and substantially parallel with the longitudinal axis of the disc, wherein the shaft is coupled to a linear-to-rotary transmission unit for converting linear motion of the shaft to rotary motion of the disc, the linear-to-rotary transmission unit comprising: a sleeve coaxially surrounding a portion of the shaft, the sleeve operatively coupled to the disc, a wall of the sleeve having a camming groove formed therein, the camming groove having a first portion and a second portion; and a cam follower extending radially outward from an outer surface of the shaft, the cam follower positioned within the camming groove, wherein the cam follower and the camming groove are configured such that motion of the cam follower, within the first portion of the camming groove, in a direction parallel with a longitudinal axis of the shaft causes rotation of the sleeve; and a secondary cam coupled to the shaft, the secondary cam configured to abut a surface of the disc located on a side of the disc opposite the valve seat when the disc is in the third position, the secondary cam positioning the disc in sealing engagement with the valve seat when the disc is in the third position. a valve body having a fluid flow path extending therethrough; a valve seat located in the valve body; a disc located in the fluid flow path of the valve body, the disc rotatable between a first position and a second position about an axis substantially perpendicular to a longitudinal axis of the disc, the disc translatable between the second position and a third position in a direction substantially parallel to the longitudinal axis of the disc; and an actuation unit operatively coupled to the disc, wherein the actuation unit comprises a piston, a shaft of the piston extending within the fluid flow path of the valve body, wherein the actuation unit further comprises a spring element operatively coupled to the shaft and the disc, the spring element imposing a biasing force on the disc in a direction away from the valve seat and substantially parallel with the longitudinal axis of the disc, wherein the shaft is coupled to a linear-to-rotary transmission unit for converting linear motion of the shaft to rotary motion of the disc, the linear-to-rotary transmission unit comprising: a sleeve coaxially surrounding a portion of the shaft, the sleeve operatively coupled to the disc, a wall of the sleeve having a camming groove formed therein, the camming groove having a first portion and a second portion; and a cam follower extending radially outward from an outer surface of the shaft, the cam follower positioned within the camming groove, wherein the cam follower and the camming groove are configured such that motion of the cam follower, within the first portion of the camming groove, in a direction parallel with a longitudinal axis of the shaft causes rotation of the sleeve; and a sleeve coaxially surrounding a portion of the shaft, the sleeve operatively coupled to the disc, a wall of the sleeve having a camming groove formed therein, the camming groove having a first portion and a second portion; and a cam follower extending radially outward from an outer surface of the shaft, the cam follower positioned within the camming groove, wherein the cam follower and the camming groove are configured such that motion of the cam follower, within the first portion of the camming groove, in a direction parallel with a longitudinal axis of the shaft causes rotation of the sleeve; and a secondary cam coupled to the shaft, the secondary cam configured to abut a surface of the disc located on a side of the disc opposite the valve seat when the disc is in the third position, the secondary cam positioning the disc in sealing engagement with the valve seat when the disc is in the third position.