0781-0043 - Victor SR250D-540 Medium Duty Oxygen Regulator, CGA-540, 5-125 PSIG

Victor SR250D-540 Single Stage Oxygen Regulator Overview

The Victor SR250D-540 (SKU: 0781-0043) is a professional-grade single-stage regulator designed for medium-duty industrial applications. Engineered to manage oxygen flow with precision, this regulator is compatible with medium to large cylinders utilizing a CGA-540 inlet connection. The unit is built upon a foundation of a die-forged brass body, which offers exceptional resistance to deformation and wear in harsh workshop environments. The housing cap is also die-forged brass, ensuring that the entire pressure-containing envelope maintains structural integrity under high-pressure conditions up to 3000 PSIG.

At the core of the SR250D-540's performance is its flow control mechanism. It features a 1.75-inch diaphragm, constructed from fabric-reinforced neoprene, which provides a responsive and stable delivery pressure ranging from 5 to 125 PSIG. This large diaphragm area allows for sensitive adjustments and consistent flow rates, making it suitable for a variety of cutting and welding tasks. The regulator utilizes a stem-type seat mechanism which aids in reliable sealing, minimizing the risk of creep or leaks. Flow control is further optimized by a precision-machined nozzle and a flow coefficient (Cv) of 0.109, ensuring that the regulator delivers at least the stated upper range of its capacity.

Operational safety and ease of maintenance are key aspects of the SR 250 series design. The regulator includes an external self-reseating relief valve, which protects the regulator housing from over-pressurization (note: this does not protect downstream equipment). To prevent particulate contamination, which is a common cause of regulator failure, the inlet is protected by a sintered bronze filter that has been electroless nickel-plated for corrosion resistance. Adjustment is facilitated by a brass adjusting screw equipped with a forged T-handle, utilizing a Delrin insert bushing and a stainless steel ball in the key to ensure smooth, low-friction operation even after years of service.

The unit comes equipped with two 2-inch brass gauges: a high-pressure gauge reading up to 4000 PSIG for cylinder content, and a low-pressure gauge reading up to 200 PSIG for delivery pressure. The outlet connection is a standard 9/16" - 18 UNF (Right Hand Male), making it compatible with standard oxygen hoses used in oxy-fuel setups.