Pressure Gauge

Turns "the boiler is groaning" into a number.

Crafting

G
T
P

G is a Glass Pane, T is a Copper Tubing and P is a Copper Plate.

Using it

Right-click a Boiler or a Pressure Vessel to read its pressure in Pu on the action bar. It only reads; it can't vent or relieve anything.

It's rough

The gauge reads in steps of 0.5 Pu. The danger line is 5 Pu, critical is 7 and a boiler starts to seep at 3.5, so you can see the danger line coming without reading the exact figure.