Mid-West Instrument

The model 121 Indicating Differential Pressure Switch is a heavy–duty version of the 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 1/2-in. NPT conduit interface and a removable cover. A variety of switching configurations are available with one or two hermetically sealed switches in SPST, SPDT configuration with 240 V, 3 W or 60 W 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 6,000 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 include:

  • Rugged, field proven design of 120
  • Terminal strip for one or two switches
  • Variety of wwitch configurations
  • Aluminum or 316 SS
  • Standard five-year warranty
Product Type:
Mid-West Instrument