A valve arrangement for use in limiting the pressure of fuel within an accumulator volume of an accumulator fuel system to a predetermined threshold level, the valve arrangement comprising: a valve outlet passage (54, 56) for communication with a low pressure drain, wherein the valve outlet passage (54, 56) extends laterally from the valve housing bore; a valve housing provided with a valve housing bore for receiving fuel from the accumulator volume; a valve member having a closed position in which it is engaged with a valve seating defined by the valve housing bore to prevent fuel flow from the accumulator volume to the valve outlet passage (54, 56); a piston member; biasing means for urging the valve member towards the valve seating through the piston member; a first restricted flow means for restricting the flow of fuel between the accumulator volume and the valve outlet passage (54, 56) during a first stage of valve opening movement as soon as the valve member is lifted from the valve seating; the valve arrangement being characterised in that, it further comprises a second restricted flow means effective during a second stage of valve opening movement which follows the first stage to provide a greater restriction than during the first stage; and a third restricted flow means effective during a third stage of valve opening movement which follows the second stage to provide a variable restriction to fuel flow dependent on the extent of opening of the valve outlet passage (54, 56) and wherein the piston member is arranged to substantially occlude the valve outlet passage (54, 56) during the first and second stages of valve opening movement, and wherein the valve outlet passage (54, 56) is gradually uncovered during the third stage of valve opening movement, and wherein the first restricted flow means is defined between the valve member and the valve seating, and wherein the second restricted flow means is defined by the piston member and a portion of the valve housing bore. a valve outlet passage (54, 56) for communication with a low pressure drain, wherein the valve outlet passage (54, 56) extends laterally from the valve housing bore; a valve housing provided with a valve housing bore for receiving fuel from the accumulator volume; a valve member having a closed position in which it is engaged with a valve seating defined by the valve housing bore to prevent fuel flow from the accumulator volume to the valve outlet passage (54, 56); a piston member; biasing means for urging the valve member towards the valve seating through the piston member; a first restricted flow means for restricting the flow of fuel between the accumulator volume and the valve outlet passage (54, 56) during a first stage of valve opening movement as soon as the valve member is lifted from the valve seating; the valve arrangement being characterised in that, it further comprises a second restricted flow means effective during a second stage of valve opening movement which follows the first stage to provide a greater restriction than during the first stage; and a third restricted flow means effective during a third stage of valve opening movement which follows the second stage to provide a variable restriction to fuel flow dependent on the extent of opening of the valve outlet passage (54, 56) and wherein the piston member is arranged to substantially occlude the valve outlet passage (54, 56) during the first and second stages of valve opening movement, and wherein the valve outlet passage (54, 56) is gradually uncovered during the third stage of valve opening movement, and wherein the first restricted flow means is defined between the valve member and the valve seating, and wherein the second restricted flow means is defined by the piston member and a portion of the valve housing bore.