Spirax-Sarco 55226 Main Valve

The Spirax Sarco 55226 is a rugged 1-1/2" NPT main valve engineered for precision high-capacity steam regulation. As the foundational component of the 25-series pilot operated regulator system, this cast iron valve body is rated for up to 250 psi and 450°F, making it a standard for heating and process steam applications. Its normally closed design ensures a positive ANSI/FCI 70-2 Class IV shut-off, preventing steam leakage during dead-end service. This pilot operated pressure reducing valve is built with durable stainless steel internals to resist corrosion and a fatigue-tested diaphragm that operates without a piston to eliminate the risk of sticking in high-duty cycles. The Spirax Sarco 25P series allows for modular configuration, enabling technicians to mount pressure, temperature, or electric pilots directly to the main body for tailored control. For optimal performance, ensure horizontal installation with a steam trap upstream to prevent condensate-induced water hammer.

Key Benefits:

• Modular Pilot Compatibility: Ready for integration with 25P, 25T, or 25PT pilots to handle pressure and temperature control simultaneously.
• Dead-End Shut-Off: Achieves Class IV shut-off ratings, critical for protecting downstream equipment and reducing energy loss when steam isn't required.
• Maintenance-Friendly Design: Features a patented self-scrubbing guide that clears away line debris, extending the service life of valve seats and heads.
• Versatile 1.5 Inch Connection: The standard 1-1/2 inch FNPT threading provides a secure, high-flow connection points for industrial boilers and heat exchangers.
• Reliable Diaphragm Action: The large diaphragm surface area delivers high sensitivity and response speed to downstream load changes.

Common Questions:

Which pilots are compatible with the Spirax Sarco 55226?
This main valve is designed to pair with the 25P (pressure), 25T (temperature), 25PT (combined), and 25PE (electric) pilots. Note that pilots must be ordered separately based on your specific pressure range or control requirements.

Does this valve require an external sensing line?
Yes, for pressure reducing applications, a 1/4" or 5/16" external sensing line should be installed at least 10 pipe diameters downstream from the valve to ensure the pilot accurately monitors stable pressure.

Can I use this valve for liquids or air?
While primarily used for steam, the 25-series is suitable for air or water as long as they are compatible with the cast iron body and stainless steel trim. Always verify pressure-temperature limits for non-steam media.

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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.