Barksdale D1H-M3 Industrial Pressure Vacuum Switch

The Barksdale D1H-M3 is a single-setpoint, diaphragm-style pressure or vacuum switch housed in a rugged NEMA 4 enclosure for industrial control systems. It supports positive-pressure service up to 150 psi, and in its vacuum variants (the D1H family) covers vacuum ranges from 0.06 to 30 inches of mercury, enabling reliable monitoring across a wide range of applications. The unit is designed for external adjustment with tamper-resistant access and uses a standard 1/4" NPT female pressure connection, with optional pressure-connection configurations available as 3SS, 80SS, or 150SS to suit different piping layouts. Electrical ratings for common configurations are up to 10 A at 125/250 VAC (3 A at 480 VAC), with alternative options defined for other voltage classes. As a housed, single-setpoint switch, the D1H-M3 is well suited for straightforward integration into process control, pneumatic and hydraulic systems, compressors, and pumps, delivering a discrete electrical signal when the sensed pressure or vacuum crosses the preset point. This combination of durable enclosure, adjustable setpoint, and versatile connection options makes it a reliable choice for industrial monitoring and interlock or alarm applications across manufacturing and utility infrastructures.