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ABLE are Mid-West Instrument’s Representative for Sales and Service in the UK and Ireland and can assist you and your customers in the following areas:

  • Application expertise
  • Our factory trained engineers offer after sales support, service and maintenance (contracts available)
  • Offer advanced Mid-West Instrument pressure gauge product training, either in-person or via video call.

Mid-West Model 106 Bellows Type Differential Pressure Gauge, 3 – 30 PSID

ABLE Instruments are Mid-West Instrument’s Official Representative for Sales and Service in the UK and Ireland, including the Model 106 Bellows Type Differential Pressure Gauge (0-3 to 0-30 PSID or equivalent). The Model 106 Bellows ΔP Gauge offers exceptional accuracy of ± 1/2% or ± 1% full scale, making it a reliable choice for precise differential pressure measurements. This DP pressure gauge operates by applying system pressure to an internal bellows and mechanical linkage assembly. As pressure changes, the bellows and linkage move, producing an electrical signal or causing a gauge pointer to move. The Model 106’s core components include a durable two-piece body, a bellows sensing element with an over-pressure assembly, a torque tube assembly, a range spring, and a gauge front assembly.

Key features of the Mid-West Model 106 include a rugged bellows sensing element, a glass-reinforced thermoplastic dial case, and a weather- and corrosion-resistant gauge front. The 270° dial arc and shatter-resistant lens ensure durability and readability. Available in 4-1/2” and 6” dial sizes, with scale ranges from 0-80” H2O to 0-800” H2O, this bellows type differential pressure gauge supports various units, including bar, mbar, and kPa. With a working pressure capacity of up to 6000 PSIG and an operating temperature range of -40°F to +200°F, the Model 106 is built to withstand harsh conditions. Its applications span pressurised tank level monitoring, water treatment, pump performance monitoring, and more, making the Mid-West Instrument Model 106 a versatile and dependable tool in various industries.


  • Durable bellows sensing element
  • Panel-mountable dial case made of glass-reinforced thermoplastic
  • Front of gauge is resistant to weather and corrosion
  • 270° dial arc
  • Shatter-resistant lens
  • Over-range protection for both High over Low and Low over High
  • Locked-Logic and Micro Switch options available

Have a particular application / project in mind? We’d welcome a call on +44 (0) 1189 169 420, or email us now at [email protected]

The two-piece body design ensures robust pressure containment and securely clamps the sensing element and over-pressure assembly, isolating high and low side pressures. The high side body half also serves as a mounting point for the torque tube assembly and the gauge front assembly. A standout feature of the Model 106 is its bidirectional relief valve, which provides over-pressure protection in both directions. When over-pressured from the high side, a mechanical stop opens the valve as the sensing element reaches its maximum deflection. Conversely, on the low side, the spring-loaded valve opens when differential pressure exceeds its rating, equalising pressure and protecting the unit.

What is the ‘Locked-Logic’ switch option? The “Locked Logic” alarm control is a solid-state optical-electronic control option for Mid-West Models 106 differential pressure gauges, designed to maintain gauge accuracy. The standard unit operates on 8 to 28 VDC power, with optional inputs of 115 VAC or 220/240 VAC (50-60 hertz). The output interface includes one or two isolated SPDT or DPDT relay contacts, with adjustable set pointers within 5% of full scale. An adjustable deadband option allows the right set pointer to trigger the upper limit and the left to trigger the lower limit. The unit features weather-proof NEMA 4X or NEMA 7 enclosures and is suitable for hazardous locations, including Class I Division I and Class II Division I groups. Furthermore, the Model 106 (6″ dial only) can be equipped with one or two independently adjustable SPDT switches which can be set on decreasing or on increasing pressure.

Model 106 Specifications:

For Full Specifications
Dial Sizes
4-1/2” and 6” Diameters
Dial Scale Ranges
0-80” H2O to 0-800” H2O (0-3 PSID to 0-30 PSID)
Differential Full Scale Ascending Accuracy
±1/2% (ASME B40.1 Grade 2A)
±1% (ASME B40.1 Grade 1A)
Available Dial Scales
Bar, Mbar, kPa, Kg/Cm2, Dual Scale and Square Root for Flow Indication etc.
Working Pressure
Up to 6000 PSIG (400 Bar)
Operating Temperature
-40°F to +200°F (-40°C to +93°C)
Material (Body)
Aluminium, Carbon Steel, 316/316L Stainless Steel and Brass (Wetted Part)
Internal Wetted Parts
316 Stainless Steel
Process Connection
Dual Top and Bottom
O-rings Material
Buna-N, Viton, and Ethylene Propylene
Purchase Product

Price: POA Contact 247ABLE