McDonnell & Miller 53 Water Feeder

The McDonnell & Miller 53 is a heavy-duty mechanical water feeder engineered for maintaining precise water levels in large-scale low pressure steam and hot water boilers exceeding 5,000 sq. ft. in capacity. Featuring rugged 1" NPT connections, this part number 136900 is designed to handle a maximum vessel pressure of 75 PSI, offering a significantly higher threshold than the standard 35 PSI found in the Series 51 counterparts. The unit provides proportional feed action, which ensures a steady, modulated response to water level fluctuations rather than a simple on/off flow, reducing system shock and improving thermal efficiency.

This float-operated feeder includes a quick-change replaceable cartridge valve and an integrated strainer, allowing for streamlined field maintenance and protection against pipe scale and debris. While it functions as a standalone mechanical feeder, the Model 53 is field-upgradable with a No. 2 switch to integrate low water cut-off (LWCO) safety functions. With a maximum water supply pressure of 150 PSI and a maximum inlet temperature of 120°F, it is a reliable choice for commercial and industrial hydronic and steam applications where maintaining a minimum safe water level is critical.

Key Benefits

• Proportional Feed Action: Delivers a consistent and measured water supply to avoid rapid temperature swings in the boiler.
• High Pressure Rating: Rated for up to 75 PSI max vessel pressure, making it suitable for demanding boiler water level control requirements.
• Integrated Protection: Features a built-in strainer to prevent valve fouling from sediment and system rust.
• Field Upgradeable: Can be converted to a combination feeder and low water cut-off by adding a No. 2 switch.
• Simplified Maintenance: Utilizing a quick-change cartridge design allows technicians to service the unit without full disassembly.

Common Questions

What is the main difference between the Series 51 and Series 53?
While both are for boilers over 5,000 sq. ft., the Series 53 handles a higher vessel pressure of 75 PSI compared to the 35 PSI rating of the Series 51. Ensure your boiler operating pressure does not exceed the unit's rating before installation.

How often should the strainer be cleaned?
The integrated strainer should be inspected annually. If the system has high makeup water demands or known sediment issues, more frequent cleaning is required to prevent flow restriction.

Can this be used on both steam and hot water systems?
Yes, the McDonnell & Miller 53 is designed for both hot water boilers and low pressure steam applications, provided the system parameters stay within the 75 PSI vessel limit.

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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.