Ashcroft 83221 Pressure Gauge 3.5 in Dial Npt Lower Mount

Product Description

The ASHCROFT 83221 is an analog pressure gauge designed for accurate pressure measurement across a wide range of trade and industrial applications. It features a 3.5-inch dial with a pressure range of -30 to 100 Hg, delivering 1% of scale accuracy for reliable readings in demanding service environments. The stainless steel case provides corrosion resistance suited for plumbing, HVAC, and mechanical system monitoring. Installation uses a standard 1/4-inch NPT lower-mount connection, making it compatible with common fittings found throughout the trade. Licensed plumbers, HVAC technicians, and mechanical contractors install this gauge where dependable pressure indication is required.

This gauge is appropriate for residential and light commercial applications including pressure testing, system diagnostics, pump performance monitoring, and piping system verification. The lower-mount (bottom-entry) configuration positions the dial face upward for easy reading when the gauge is installed in a vertical pipe or manifold. The non-liquid-filled design keeps the unit lightweight and suitable for dry, vibration-controlled environments where damping fluid is not required.

Key Features

• 3.5-inch analog dial for clear, at-a-glance pressure readings
• Pressure range of -30 to 100 Hg covers both vacuum and positive pressure measurement
• 1% of scale accuracy for reliable diagnostic and monitoring use
• 1/4-inch NPT lower-mount connection fits standard trade fittings
• Stainless steel case resists corrosion in wet or humid service environments
• Non-liquid-filled construction suited for low-vibration installations

Compatibility

Designed as a general-purpose replacement or installation gauge for residential and light commercial plumbing, HVAC, and mechanical piping systems using standard 1/4-inch NPT lower-mount gauge ports.

Installation Notes

Installation should be performed by a licensed plumber or HVAC technician in accordance with applicable local codes and IPC or IFGC guidelines. Isolate and depressurize the system completely before removing any existing gauge or installing this unit. Apply thread sealant tape to the NPT threads before making the connection — do not overtighten, as stainless steel fittings can gall. Verify the system pressure is within the gauge range before returning the system to service.