Wika 4255985 Pressure Gauge 4 in 0-30 Psi 1/4 Npt Lower

Product Description

The WIKA 4255985 is an analog pressure gauge designed for monitoring system pressure in plumbing, HVAC, and general industrial service applications. It features a 4-inch dial for easy readability and mounts via a 1/4-inch NPT lower-mount connection. The gauge operates over a 0 to 30 psi range with a 3-2-3 percent of scale accuracy rating, meaning it reads within 3 percent at the low and high ends of the scale and 2 percent in the mid-range. The ABS case provides lightweight durability, while brass wetted parts offer reliable corrosion resistance in water and air service. No liquid fill is used in this model. Licensed plumbers, HVAC technicians, and mechanical contractors typically install this type of gauge.

This gauge is suited for residential and light commercial applications where low-pressure monitoring is required. Common installations include domestic water systems, compressed air lines, boiler supply and return piping, and HVAC hydronic loops. The lower-mount NPT connection allows for direct panel or pipe installation in tight spaces. The 4-inch dial diameter improves at-a-glance readability on equipment rooms and mechanical panels.

Key Features

• 4-inch analog dial for clear pressure readings at a distance
• 0 to 30 psi pressure range suitable for low-pressure water and air systems
• 3-2-3 percent of scale accuracy across the full dial range
• 1/4-inch NPT lower-mount connection for direct pipe or panel installation
• ABS case construction — lightweight and impact-resistant
• Brass wetted parts for corrosion resistance in water and air service
• No liquid fill — dry gauge for standard service conditions

Compatibility

Designed as an OEM-style replacement or new-installation gauge for residential and light commercial plumbing, HVAC hydronic, and compressed air systems requiring a 1/4-inch NPT lower-mount analog pressure gauge rated to 30 psi.

Installation Notes

Installation should be performed by a licensed plumber or qualified mechanical technician. Shut off system pressure and depressurize the line completely before removing or installing any pressure gauge. Apply thread sealant or PTFE tape to the NPT threads per local plumbing code requirements — do not overtighten, as ABS-cased gauges can crack at the socket. Verify that the system operating pressure does not exceed 30 psi to avoid damage to the gauge or an inaccurate reading.