Products Description
P-12 Differential Pressure Switch Unit

Module Feature
P-12 is a diaphragm type differential pressure switch.
It detects pressure difference between high side and low side port. The setpoint can be adjusted on site by internal screw. Equipped with SPDT dry contact for alarm or interlock. Diaphragm sensor is suitable for air and non-corrosive clean liquid. Compact housing, easy for pipe or panel mounting. Widely stocked as spare for dust filter, fan, air handling unit and small process skid.
Working principle
Pressure difference acts on both sides of diaphragm.
When ΔP exceeds adjusted threshold, diaphragm displacement triggers mechanical snap action switch. Contact changes state to send alarm or interlock signal. When differential pressure drops below reset value, switch resets automatically.
Onboard components
Sensing diaphragm, adjustable spring, snap-action switch, high/low pressure port, adjustment knob, wiring terminal and enclosure.
LED indicators
No built-in LED; status is judged by contact signal.
Hardware self‑diagnosis
Check port blockage, diaphragm damage and contact continuity. Calibration uses manometer.
Programming software
Not applicable, mechanical switch.
Electrical & Process Parameters
Model:P-12 Brand:General industrial Device type:Diaphragm differential pressure switch Function:Differential pressure monitoring and alarm for filter and air system
Mechanical & Structure
Mounting:Wall or pipe mounting Protection class:IP65 Housing:Plastic or die-cast aluminum
Environmental
Operating temperature:-20℃ ~ +70℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing
Certification:CE Status:Original industrial pressure switch spare
Installation
Clean pressure pipe before installation.
Connect high and low pressure port correctly, adjust setpoint, test switch action and reset after commissioning.
Interface
High pressure tap, low pressure tap, SPDT contact terminals.
Diagnostic
No switching action: Diaphragm rupture, port blocked, spring fatigue. Chattering: Pressure fluctuation near setpoint.
Product BriefP-12 switch, industrial differential pressure switch spare for filter and air skid replacement.