OEM

Differential Pressure Indicators

Explore Mid-West Instrument’s OEM Differential Pressure Indicator choices, offering precision and reliability for various applications. From piston-type to diaphragm-type indicators, our range ensures accurate measurements in water systems, compressed air, and more. Discover how our indicators elevate pressure monitoring and optimize system performance.

0-3.5 PSID to 0-100 PSID

Safe working Pressures up to 3,000 PSI
Rugged Construction / Some Units Weather Proof designs
5% Accuracy
Calibrated to Color Breaks Only
Designs configured to customer needs
Indicator only or with Switch options
Common Applications:
- Filter Monitoring
- Strainer Monitoring
- Water System Applications
- Compressed Air
- Hydraulic
- Refrigerant
- Heat Exchanger Pressure Drop Monitoring
25 Piece Minimum Order

Piston Type

Model 126/127

The Model 126/127 Series differential pressure indicator with optional switch is a piston-type gauge. It is low cost and reliable for measuring pressure drop across filters, strainers and separators.

126 Range: 0-5 PSID thru 0-20 PSID (0.35 bar thru 1.4 bar)
127 Range: 0-25 PSID thru 0-100 PSID (1.75 bar thru 7.0 bar)
Max. Static Pressure 3000 PSIG (69 bar)
Switch Configurations:
- Clamp On
- Stick on or Screw On Flat Pack
Switch Rating Options:
- SPDT 3 W, 0.25 Amp, 125 VAC/VDC
- SPST 60W, 3 Amp, 240 VAC/VDC

Model 126 Model 127

Diaphragm Type

Model 146

The Model 146 Series differential pressure indicator is a diaphragm-type ∆P gauge that has total separation between the high and low sides. Additionally, switch options are available.

Range: 0-50” H2O thru 0-30 PSID (0.125 mbar thru 2.0 bar)
Max. Static Pressure 1000 PSIG (69 bar)
Switch Configurations:
- Clamp On
- Stick on or Screw On Flat Pack
- DIN IP65 Connector (Preset Switch Only)
Switch Rating Options:
- SPDT 3 W, 0.25 Amp, 125 VAC/VDC
- SPST 60W, 3 Amp, 240 VAC/VDC

Model 146

Model 444

The Model 444 Series Differential Pressure Indicator offers a simple, yet functional design for use with filters, strainers, etc. Indication –Green / Red Sliding Indication with Nylon Lens. This low cost indicator makes the perfect alternative to more costly differential pressure gauges where readability, small size and price are important considerations.

Range: 0-5 PSID thru 0-25 PSID (0.35 bar thru 1.7 bar)
Max. Static Pressure 300 PSIG (20 bar)

Model 444

Model 522 OEM

Model 522 OEM – Mid-West Instrument rolling diaphragm type gauge is a very competitively price gauge/switch. The Model 522 Differential Pressure Gauge & Switch is compact and weather resistant for challenging DP Applications and installations. It is suitable for use in outdoor and “Hose Down” applications. Available with our popular DIN Plug connector or Flat Pack Switch. Both are available in a SPDT or SPST configurations . Model 522 is available with a Full scale accuracy of ±5% (0-5 PSID to 0-50 PSID)

Range: 0-5 PSID thru 0-50 PSID (0.35 bar thru 3.4 bar)
Max. Static Pressure 1000 PSIG (69 bar)
Weather- proof lens design
Over-Range protection Hi – Lo (200 PSID)

Model 522

Model 555

The Model 555 Series Differential Pressure Gauge offers a two-sided dial, for use with filters, strainers, etc. 555 Provides easier installation regardless of flow direction. The rolling diaphragm sensing element isolates the high and low side of the indicator assuring filter efficiency (Reverse pressure must be avoided) While this low cost gauge is a “step up” from the Model 444, it still provides another alternative to the more costly differential pressure gauges with equivalent functionality. No switch options available.

Range: 0-5 PSID thru 0-50 PSID (0.35 bar thru 3.4 bar)
Max. Static Pressure 300 PSIG (20 bar)
Simple Molded Design
Color Dials
Dual Display
Buna or FKM Elastomer Seals

Model 555

OEM Indicators “Piston Type”

Model No.	Differential Pressure Range	Accuracy	Working Pressure	Electrical Available	Specifications	Installation/ Operation Manual	Electrical IOM	Drawing
Model 126	0-5 PSID to 0-20 PSID	±5%	3,000 PSI	Available CE Marked to LVD & RoHS		N/A	N/A
Model 127	0-25 PSID to 0-100 PSID	±5%	3,000 PSI	Available CE Marked to LVD & RoHS Directives		N/A	N/A

OEM Indicators “Diaphragm Type”

Model No.	Differential Pressure Range	Accuracy	Working Pressure	Electrical Available	Specifications	Installation/ Operation Manual	Electrical IOM	Drawing
Model 146	0-3 PSID (0-50" H2O) to 0-30 PSID	±5%	1,000 PSI	Electrical Enclosures Weather-Resistant, NEMA 4X		N/A	N/A
Model 444	0-5 PSID to 0-30 PSID	±5%	300 PSI	None available	N/A	N/A	N/A
Model 522 (OEM)OEM	0-5 PSID to 0-50 PSID	±5%	1,000 PSI	Available CE Marked to LVD & RoHS Directives, SPST & SPDT Switches	N/A	N/A	N/A	N/A
Model 555 (OEM)Tri-Color	0-3.5 PSID to 0-43 PSID	±5%	300 PSI	Not Available		N/A	N/A