Murphy 20T-300-8-1/2 Temperature Switch Gauge Part No. 10702069

20T-300-8-1/2: 2" Temperature Swichgage; 140-300° F. Temp Range; 8 Ft. Capillary Length (10702069)

The 20T-300-8-1/2 is a part of the 20 Series (2 inch/51 mm dial) SWICHGAGE models which are diaphragm-actuated, temperature-indicating gages, with built-in electrical switches for tripping alarms and/or shutdown devices. Ranges from 300-440°F (160-220°C).

The gage mechanism is enclosed in a steel case coated to resist corrosion. A polycarbonate, break resistant lens and a polished, stainless steel bezel help protect this rugged, built-to-last instrument. These vapor actuated gages feature a sealed capillary tube and a sensing bulb. When subjected to heat, the liquid in the sensing bulb changes to vapor creating pressure against the diaphragm mechanism. The diaphragm translates this vapor pressure into a mechanical gage reading.

For series 20T, the gage pointer acts as a temperature indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contact(s) are grounded through the SWICHGAGE case. They have self-cleaning motion to enhance electrical continuity.