Our tank has several fittings. We used an in-line check valve between the compressor and tank so the pressure wouldn't bleed down. The trick big-rig type plastic pressure hose and fittings our Teraflex T-Locker uses are in the foreground. More on that in a later issue. Behind it is our pressure switch that engages the compressor when pressure drops below 90psi and shuts it off when pressure reaches 120psi.