Model 120

Piston Type Gauges

Model 120 – The Mid-West Instrument piston type gauge is our most versatile and customizable differential pressure gauge to fit your most demanding requirements. Available with multiple switch options including Hazardous location options. With a Full scale accuracy of ±3/2/3% combined with Differential pressure dial scales of 0-5 PSID to 0-110 PSID this rugged design is ready to do the job.

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Center Zero Instrument

Product Features/Benefits

  • Simple Rugged Piston Type Design Sensing Element
  • Glass Reinforced Thermoplastic Dial Case (Panel Mountable)
  • Anodized Aluminum Dial Case Option available contact sales for more information
  • Weather Resistant & Corrosion Resistant
  • Shatter Resistant Lens
  • Over-Range Protection, High over Low and Low over High
  • 5 Year Warranty
  • For complete model details See Bulletin_120a.pdf
  • Installation and Operation Manual See Bulletin: IOM_120.pdf

Specifications / Configuration

  • Dial Sizes available: 2-1/2”, 3-1/2”, 4-1/2” and 6” Diameters (Uni-Directional & Bi-Directional)
  • Dial Scale Ranges: 0-5 PSID to 0-110 PSID (0-0.35 bar to 0-7.0 bar)
  • Full Scale Ascending Accuracy ±3/2/3% (ASME B40.1 Grade B)
  • Working Pressures up to 6000 PSIG (400 Bar)
  • Operating Temp -40°F to +200°F (-40°C to +93°C)
  • Weather Protection NEMA 4X
  • Material of Construction of Body - Aluminum, 316/316L Stainless Steel, Alum/Bronze and Monel (Wetted Part)
  • Internal wetted parts-316 Stainless Steel, Ceramic Magnet, Alum/Bronze, Monel (Dependent on model chosen)
  • Multiple instrument process connection size and locations available
  • O-Ring Materials: Buna-N, Viton, Neoprene, Teflon, Ethylene Propylene (Perfluoroelastomer optional)
  • For complete specifications see: Specificationsheet_120.pdf

Common Applications

  • Filters and Strainer Monitoring
  • Compressed Air
  • Hydraulic
  • Refrigerant
  • Pump Performance Testing
  • Heat Exchanger Pressure Drop Monitoring
  • Valves, Chillers etc.. and for local flow indication and control.

Switch Electrical Specifications:

See Bulletin ELECIOM_120

Mid-West Instrument Model 120 switches are mechanically adjustable allowing the customer to set the switch within a defined adjustment span of range of the instrument. The Model 120 can be configured with 1 or 2 switches. For 2 switch units the switches are independently adjustable. Mid-West can also pre-set switch set point(s) upon customer request. For complete switch specifications see the Electrical Installation and Operation Manual

  • No Power required to operate switches
  • 1-2 Independent adjustable Switches
  • Numerous available switch output options
    • SPDT 3W, 0.25 Amp, 125 VAC/VDC
    • SPST 60W, 3.0 Amp, 240 VAC/VDC (Normally Open)
    • SPDT 60W, 3.0 Amp, 240 VAC/VDC (Normally Closed)
    • SPST 60W, 3.0 Amp, 240 VAC/VDC (1) Normally Open, (1) Normally Closed
    • SPDT 60W, 1.0 Amp, 240 VAC/VDC
  • Non-Hazardous switches CE Marked in Accordance With Low Voltage & RoHS Directives
  • Electrical Enclosures Weather-Resistant, NEMA 4X
  • DIN Connector Option
  • Hazardous Locations Options
    • Class I Division 1, Class II, Division 1
    • Class I Division 2, Class II, Division 2
    • Complete assembly 3rd Party Certified

Additional Options:

  • Pipe Mounting Kit - 2" U-Bolt
  • Wall Mounting - Rear Mount
  • Rear Mounting Holes
  • Liquid Fill
  • Oxygen Cleaning
  • Maximum Follower Pointer
  • NACE Compliance
  • CRN – Canadian Registration Number

The Mid-West Advantage

Model 120Documents

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“Piston Type” Gauges with Electrical Optional

Model No. Differential Pressure Range Accuracy Working Pressure Electrical Available Specifications Installation/ Operation Manual Electrical IOM Drawing
Model 120 0-5 PSID to 0-110 PSID ±3/2/3% Up to 6,000 PSI CE / LVD, RoHS Compliant, NEMA 4X, Flying Leads / DIN Connector, Class 1-Div. 1, Class 1-Div. 2
Model 122 0-5 PSID to 0-110 PSID ±5% 3,000 PSI CE / LVD, RoHS Compliant
Model 123 0-150 PSID to 0-400 PSID ±3/2/3% Up to 5,000 PSI CE / LVD, RoHS Compliant, NEMA 4X, Flying Leads / DIN Connector, Class 1-Div. 2
Model 124 0-5 PSID to 0-110 PSID
and
0-150 PSID to 0-400 PSID		 ±3/2/3% 10,000 PSI CE / LVD, RoHS Compliant, NEMA 4X, 4-20mA Transmitter

Electrical “Piston Type” Gauges

Model No. Differential Pressure Range Accuracy Working Pressure Electrical Available Specifications Installation/ Operation Manual Electrical IOM Drawing
Model 121 0-5 PSID to 0-100 PSID ±3/2/3% Up to 6,000 PSI CE / LVD, RoHS Compliant, NEMA 4X,Terminal Strip, Class 1-Div. 2, 4-20mA Transmitter N/A
Model 220 0-5 PSID to 0-100 PSID ±3/2/3% Up to 4,000 PSI CE / ATEX / RoHS Compliant, KOSHA CERTIFIED, NEMA 4X, Terminal Strip, Class 1-Div. 1, Class 1-Div. 2, 4-20mA Transmitter N/A