The SAS cylinder is just a sealed hydraulic cylinder mounted between the steer axle and the frame and strokes as the steer axle articulates. It has a solenoid valve connecting the two chambers, in the cylinder, on each side of the piston in there. The solenoid is energized and open when everything is normal and the forklift is operating safely. If the SAS sensor detects that the lift is rocking to the side, and trying to roll over, it shuts off the solenoid valve and that locks the steer axle from rolling. It changes the forklift from a normal triangle 3 point stance to a square 4 point stance when it detects a rolling to the side danger. An accumulator on a lift cylinder is a shock absorber to cushion the hydraulics against sharp pressures generated in the system, like going over bumps with a heavy load or lowering the load and stopping quickly. It sort of adds some bounce rather than having a bang in the lift cylinder.