A dead$-$weight tester is a device commonly used for calibrating pressure gauges. Weights loaded onto the piston carrier generate a known pressure in the piston cylinder, which in turn is applied to the gauge. The tester shown below generates a pressure of $40$ MPa when loaded with a $92$ kg weight.

Determine the diameter of the piston cylinder $($ mm $),$ and the load $($ kg $)$ necessary to produce a pressure of $160$ kPa $.$