Ashcroft 81377XLL Pressure Gauge 2.5 in 30-0-15 Psi Center Back

Product Description

The ASHCROFT 81377XLL is a dual-scale analog pressure gauge designed to read both positive and negative pressure, spanning a range of 30 inches Hg vacuum through 0 to 15 psi. The stainless steel case and bronze wetted parts make it well suited to general industrial, HVAC, and plumbing service environments where corrosion resistance and long service life are priorities. The 2.5-inch dial provides a clear, readable face in panel or field installations. Accuracy is rated at 1 percent of full scale, meeting standard requirements for diagnostic and monitoring applications. The center back mount configuration allows direct pipe connection from behind, keeping the gauge face forward-facing and unobstructed.

This gauge is used in residential and light commercial HVAC systems, hydronic heating and cooling loops, plumbing systems, and compressed air or vacuum service lines. The compound pressure range makes it especially useful wherever technicians need to monitor both vacuum and low positive pressure in a single instrument. Center back mounting suits panel-mounted and manifold installations where side or lower-mount access is limited. Licensed HVAC technicians, plumbers, and pipefitters are the typical installers.

Key Features

• Compound pressure range: 30 inches Hg vacuum to 15 psi, readable on a single analog dial
• 1 percent of full-scale accuracy for reliable diagnostic and monitoring use
• Stainless steel case resists corrosion in wet or outdoor service environments
• Bronze wetted parts compatible with water, air, and many common system fluids
• 2.5-inch dial diameter for clear field readability
• Non-liquid-filled design suits standard pressure monitoring without glycerin fill concerns

Compatibility

Designed as an OEM-style replacement or new-installation pressure gauge for residential and commercial HVAC, plumbing, and hydronic systems requiring a 1/4-inch center back mount connection and a compound vacuum-to-positive pressure range.

Installation Notes

Installation is typically performed by a licensed HVAC technician, plumber, or pipefitter. Shut off and depressurize the system fully before removing an existing gauge or threading in this unit. Apply thread sealant tape or paste to the 1/4-inch NPT threads per applicable plumbing or mechanical codes before installation. Do not use the gauge body as a wrench grip; apply torque at the hex fitting only to avoid case damage.