The Air/Water Liquid-Filled Compound Pressure Gauge (4-inch, –30 to 300 PSI) is a rugged, professional-grade instrument designed for accurate pressure measurement in fire protection, plumbing, HVAC, and mechanical systems that require both positive and negative (vacuum) indication. Built with a stainless steel case and liquid-filled design, this gauge delivers dependable performance in demanding environments where vibration, pulsation, and thermal cycling are common.
The compound scale (–30 inHg to 300 PSI) allows technicians to monitor vacuum and positive pressure on a single dial, making it ideal for systems such as air compressors, suction lines, boiler systems, and fire sprinkler air chambers. The liquid (glycerin) filling dampens pointer oscillation, reduces internal corrosion, and extends gauge life by stabilizing the movement during pulsating pressure conditions.
Featuring a 4-inch dial for easy readability, bold black markings, and a high-contrast pointer, this gauge enables quick visual verification of system status. The durable stainless steel case and polished bezel offer superior corrosion resistance in wet or corrosive environments, while the robust internals maintain accurate readings across the full range.
Designed for professional contractors, inspectors, and maintenance personnel, the 100-325-00860 liquid-filled compound pressure gauge combines precision, durability, and clear performance for everyday mechanical and fire protection applications where reliable monitoring of both vacuum and pressure is essential.
