Lightweight and compact, this gauge valve is designed with a small footprint and for maximum performance. The design provides quick, convenient access for isolating and venting of pressure gauges. The pressure gauges are positionable with tube adapter ends, eliminating threaded connections and leak points. The smaller, lightweight footprint reduces the need for supports, which place additional stress on a system. A streamlined body features tube fitting end connections for leak-tight performance, reduced installation time and cost, plus robust tube grip and vibration resistance. The design incorporates a purge valve for easy bleeding of trapped fluid pressure between the valve seat and gauge upon shutoff. The purge valve is machined directly onto the body, eliminating potential leak points while allowing the user to safely release fluid before removing the gauge. A permanently assembled purge cap is crimped to the valve body for operator safety and to prevent accidental disassembly.