The Armstrong OB-30 and OB-31 are direct-acting temperature regulators that require no external source for operation. Simple and compact, the units are suitable for a wide variety of heating/cooling applications. Installing, adjusting or maintaining the OB-30 and OB-31 is quick and easy, because interchangeable capillaries mount in any position and disconnect by simply loosening the union nut. No stem packing, so there’s no leakage. Single composition seat for tight shutoff. The OB-30 and OB-31 come in .5″, .75″ or 1″ (15–25 mm) sizes and is available with a choice of five temperature ranges and three capillary lengths.

Parameter Name	Parameter Value
Display	LED
Type	thermoelectric
Use	heating cooling
Other characteristics	compact with control/safety thermostat
Maximum temperature (°C)	185 - 185