Spirax-Sarco 55225 Main Valve

The Spirax Sarco 55225 is a high-performance 1.25 inch NPT 25-Series main valve designed for precise pressure and temperature control in industrial steam systems. This pilot-operated diaphragm valve is engineered for durability, utilizing a stainless steel diaphragm to provide high lift and maximum flow capacity. As a fundamental component of the Spirax Sarco 25P pressure reducing valve assembly, the 55225 model ensures stable downstream pressure regardless of upstream fluctuations. This cast iron steam valve is rated for saturated steam service and is commonly field-configured with various pilots, such as the 25P, 25T, or 25PT, to handle specific regulation requirements. Integrating this replacement main valve into your header ensures reliable shut-off and consistent modulation, preventing hunting or water hammer issues common in undersized alternatives. For contractors performing steam system maintenance, the 55225 offers a robust solution for retrofitting or repairing legacy pressure stations while maintaining high CV ratings.

• Interchangeable Pilot Design: Compatible with a wide range of Spirax Sarco pilots for pressure, temperature, or electric on/off control.
• Durable Construction: Features a heavy-duty cast iron body and stainless steel internals for resistance against erosion and wire-drawing.
• High Flow Capacity: The 1.25" NPT connection and optimized internal geometry provide superior flow rates compared to balanced-plug designs.
• Tight Shut-off: Engineered to meet ANSI Class IV leakage standards, ensuring system safety and energy efficiency during idle periods.
• Serviceability: Diaphragm and seat are easily accessible for routine inspection or rebuilds without removing the valve body from the line.

What is the maximum inlet pressure for the Spirax Sarco 25-Series main valve?
The standard 25-Series cast iron body is typically rated for a maximum operating pressure of 250 psi at 450°F, though specific pilot configurations may limit the operational range.

Can the 55225 main valve be used for liquid service?
No, this main valve and its associated pilot systems are specifically designed for steam and dry gas applications; using it for water or oil can lead to diaphragm failure.

Is the 55225 main valve compatible with other manufacturers' pilots?
For optimal performance and safety, it is documented that these main valves should only be paired with genuine Spirax Sarco pilots engineered for the 25-Series diaphragm stroke.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.