GA139-03 - Smith Equipment 2-Inch High Pressure Regulator Gauge 4000 PSI

Technical Overview of the Smith GA139-03 Pressure Gauge

The Smith Equipment GA139-03 is a precision-engineered replacement pressure gauge designed specifically for high-pressure industrial gas applications. Engineered to meet Smith's rigid quality standards, this gauge provides a service pressure range of 0 to 4000 PSIG (0 to 280 BAR), making it the standard choice for monitoring cylinder contents on oxygen and inert gas regulators. The unit features a 2-inch (51mm) diameter dial, which strikes an optimal balance between readability and compact footprint on regulator bodies.

Technically, the gauge utilizes a precision watch-type movement mechanism. This internal design ensures consistent and accurate pressure readings, which are critical for the safe operation of high-pressure gas delivery systems. The mechanism is housed within a durable steel case, providing robust protection against external impacts common in welding and fabrication environments. The inlet connection is a standard 1/4-inch MNPT brass nipple, located at the bottom of the case (bottom mount). This industry-standard threading ensures compatibility with the vast majority of gas pressure regulators available on the market that utilize 1/4-inch FNPT gauge ports.

Safety and durability are paramount in the design of the GA139-03. The face is protected by a one-piece polycarbonate crystal. Unlike glass, this material is shatter-resistant, significantly reducing the risk of injury in the event of a gauge failure or external impact. The crystal also features a protective lip designed to prevent damage to the gauge face itself. The gauge is U.L. Listed, confirming it meets specific safety requirements for compressed gas service. The dial face is a high-visibility cupped steel design, featuring clear, high-contrast markings for both PSI (outer scale) and BAR (inner scale) measurements, facilitating quick and accurate verification of remaining cylinder pressure.

This component is an essential maintenance item for MRO (Maintenance, Repair, and Operations) professionals managing welding equipment. It allows for the immediate restoration of regulator functionality without the need to replace the entire regulator assembly. The robust construction, combined with the dual-scale readout and universal fitment, makes the GA139-03 a reliable specification for industrial gas distribution systems requiring pressure monitoring up to 4000 PSI.