Barksdale D1T-A3SS Pressure Vacuum Actuated Switch

The Barksdale D1T-A3SS Pressure Vacuum Actuated Switch is a diaphragm-type switch that can be triggered by either positive pressure or vacuum, engineered for reliable industrial control in rugged environments. It provides a single SPDT (single-setpoint) contact housed in a robust 1/4" NPT female pressure port and a NEMA 4 enclosure for weather-resistant operation. Designed for low-pressure sensing, it covers an actuation range of 0.03–3 psi, making it suitable for precise control tasks such as damper actuation, burner safety, or small-gas-flow monitoring in HVAC and industrial systems. Electrical compatibility includes operation at 125–250 VAC and up to 480 VAC in supported variants, enabling flexible wiring for different plant voltages. The D1T family utilizes terminal-block diaphragm switches with tamper-proof external adjustment, and factory-set models are available for repeatable performance. This model combines accurate low-pressure sensing with compact, rugged construction to deliver a dependable control signal in demanding service while minimizing false trips from ambient pressurization variations.