Thermostats of this family may be easily identified by referring to the part number located on the carton and on the back and side of the device. These thermostats are used for proportional control of pneumatically activated valves, dampers and similar devices in heating, ventilating and air conditioning systems. See Table-1.
The thermostats are shipped with mounting screws and three 3/4-inch long copper tubes. Wall fittings must be ordered separately.
Air connections: Two plastic tubes reinforced with a coil spring are coded M & B. The M (Black) designates the supply main and the B (White) designates the controlled branch line.
Model TK-1601 has three plastic tubes. The additional tube A (White) designates the auxiliary (two-position) branch line.