Spirax-Sarco liquid drain traps for compressed air are available in pipe sizes from 1/4" to 1" and operating pressures from 30 to 150 psi. Liquid drain traps deploy the same lever mechanisms, valves, and seats as float and thermostatic (F&T) traps. These liquid drain traps are used to drain liquids from most gases, for example water from compressed air. The trap removes the water and prevents the escape of air.