Spirax-Sarco 55224 Main Valve

The Spirax-Sarco 55224 is a 1-inch NPT cast iron main valve engineered for precision high-capacity steam regulation in industrial environments. Built as the cornerstone of the Spirax Sarco 25-series, this pilot-operated pressure regulator provides exceptional stability and dead-end shutoff (ANSI Class IV) across varying upstream pressures. As a seasoned technician knows, the versatility of the 55224 main valve lies in its modularity—simply pair it with the appropriate 25P pressure pilot, 25T temperature pilot, or a 25PT combination to meet specific system demands. The rugged ASTM A126 Class B cast iron body and stainless steel internals are designed to withstand maximum operating pressures up to 250 psig and temperatures reaching 450°F. Featuring a fatigue-tested diaphragm and a patented self-scrubbing guide, this unit minimizes sticking and mechanical failure, ensuring your steam line remains balanced even under fluctuating load conditions.

Key Benefits for the Jobsite:

• Versatile Control: Compatible with various pilots for pressure, temperature, or electric remote shutoff applications.
• Hardened Trim: Hardened stainless steel valve head and seat provide superior resistance to erosion and wire-drawing.
• Maintenance Efficiency: Diaphragms and kits are interchangeable across the series, simplifying inventory for multi-valve facilities.
• High Accuracy: Self-actuated design uses external sensing lines for rapid response to downstream demand changes.
• Reduced Downtime: The pistonless diaphragm design eliminates common sticking issues found in inferior regulators.

Common Contractor Questions:

Can I use this valve for dead-end service?
Yes, the 25-series is rated for ANSI/FCI 70-2 Class IV shutoff, making it ideal for applications where steam is not required during off-cycles.

What is the proper sensing line placement?
For accurate regulation, the sensing line must be connected to a straight section of downstream piping, typically 10 pipe diameters away from the nearest fitting or elbow.

Does this include the pilot?
No, the 55224 is the main valve only. You must select and install the specific pilot (e.g., 25P, 25T) required for your application's set point.

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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.