The Excel Industries range of back, bottom & top inlet Bourbon type pressure gauges are an economical gauge suitable for displaying the pressure in both water and air piping systems. The Bourbon tube which is an elliptical copper tube sealed at one end flexes when pressure is applied. As it flexes the linear movement is changed to a rotational one by means of some small gears. They in-turn rotate the pointer to indicate the system pressure on a calibrated scale. The gauges are available with either a back, top or bottom ¼” BSP connection depending on the installation for a number of different pressure ranges.