Westwood Products S100-402 Compound Gauge 30-0-150 Psi

Product Description

The WESTWOOD PRODUCTS S100-402 is a compound pressure gauge designed for HVAC, plumbing, and oil burner service applications where both vacuum and positive pressure readings are required. It covers a range of 30 inches Hg vacuum to 150 psi positive pressure, making it suitable for diagnosing and monitoring systems that cycle between negative and positive pressure states. The gauge features a 2-inch face for clear readability and a 1/8-inch bottom mount connection for direct installation into standard service ports and tee fittings. Licensed technicians and service professionals install this gauge as part of diagnostic manifolds or as a fixed system gauge.

This compound gauge is used in residential and light commercial service scenarios including oil burner fuel systems, hydronic heating circuits, and refrigeration or HVAC diagnostic setups. The bottom-mount configuration allows the gauge face to remain upright and readable when threaded into a vertical or horizontal port. Its dual-range scale supports applications where technicians need to confirm system prime, check for vacuum leaks, or verify operating pressure within a single instrument.

Key Features

• Compound scale reads from 30 inches Hg vacuum to 150 psi positive pressure
• 2-inch dial face for clear field readability
• 1/8-inch NPT bottom-mount connection fits standard service ports
• Dual-range display eliminates need for separate vacuum and pressure gauges in many applications
• Compact size suited for tight installation spaces in residential equipment

Compatibility

Designed as an OEM-style replacement compound gauge for oil burner, hydronic heating, and HVAC service applications requiring a 1/8-inch NPT bottom-mount gauge with a 30-0-150 psi compound range.

Installation Notes

Installation is typically performed by a licensed HVAC technician, plumber, or oil burner service technician. Shut down the system and relieve all system pressure before removing or installing any gauge. Use appropriate thread sealant rated for the service fluid and pressure range. Do not overtighten the 1/8-inch NPT fitting, as this can damage the gauge port or fittings.