McDonnell & Miller 334100 Float and Gasket

The McDonnell & Miller 334100, identified by model number 421-30, is a specialized float and gasket kit engineered for Series 25A make-up water feeders (including 25-A and 25-AB) and Series 27-W liquid level controls. Designed for high-performance fluid management in commercial and industrial hydronic systems, this kit facilitates the precise mechanical monitoring required to prevent dry-fire conditions or overflow. The assembly includes a replacement float and float rod, ensuring a direct mechanical fit that maintains the factory-specified buoyancy curve vital for accurate switch activation. Integrating a 311100 valve bracket gasket and high-integrity sealing components, the kit ensures a leak-proof interface within the float chamber. For technicians performing boiler low water cut-off maintenance or level control overhauls, utilizing this OEM-spec float kit is essential for restoring the Series 27-W or 25A to original operating parameters without modifying existing equalizing connections or piping.

• Direct OEM Compatibility: Specifically calibrated for McDonnell & Miller Series 25A and 27-W, eliminating field-mod issues.
• Complete Replacement Assembly: Provides both the float ball and float rod for a full mechanical restoration of the level sensing linkage.
• Industrial-Grade Sealing: Includes the necessary gasket to ensure a pressure-tight seal on the float chamber head casting.
• Maintenance Efficiency: Allows for rapid service of liquid level controls without the need for additional specialized fabrication.

How do I verify if the 334100 kit fits my specific water feeder?
This kit is the specific McDonnell & Miller 421-30 replacement part for any Series 25A, 25-AB, or Series 27-W liquid level control. Always check the model plate on the feeder body before installation.

Does this float kit include the valve bracket gasket?
Yes, the assembly is designed to include the essential gasket required to reseal the head mechanism to the feeder body during a float replacement.

What is the proper procedure for tightening the head bolts?
Technicians should clean all gasket surfaces thoroughly and use an alternating star pattern to torque the bolts to approximately 14-20 ft-lbs to ensure even pressure across the 334100 gasket.

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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.