The new, model 121 Indicating Differential Pressure Switch is a heavy –duty version of the very successful Model 120 and features the rugged, field-proven piston/housing design of the 120. In addition, model 121 has a heavy-duty industrial type terminal strip for either one or two switches. Wiring is easy with _” NPT conduit interface and a removable cover. A variety of switching configurations is available with one or two hermetically sealed switches in SPST, SPDT configuration with 240 volt, 3 Watt or 60 Watt ratings. The model 121 is available in aluminum or 316 S.S. pressure housing with 316 S.S. and ceramic internal parts. Safe Working Pressure is 6000 PSIG (0-400 bar). 121 Models are available in differential pressure ranges from 0-5 PSID (0-.3 bar) to 0-110 PSID (0-7 bar) with ± 2% accuracy. The weather resistant gauge front is of reinforced engineered plastic for corrosion resistance. Benefits: ? Rugged, field proven design of 120 ? Terminal strip for 1 or 2 switches ? Variety of Switch configurations ? Aluminum or 316 SS ? 5 year warranty standard • Operating Temp - -40ºF to +200ºF (-40ºC to +93ºC) • Dial Size - 2-1/2" • Working Pressure - 6000 PSIG
