McDonnell & Miller 349500 Hook-Up

The McDonnell & Miller 349500, also identified by model number SA159-24, is a specialized lower quick hook-up fitting engineered for seamless integration with steam boiler safety controls. This critical component serves as a direct replacement part for the McDonnell & Miller Series 47 and 47-2 mechanical water feeders, as well as the Model 64-A, 42A, 67, and 42S-A low water cut-offs. Designed for professional installation, it enables a reliable connection between the control unit and the boiler's gauge glass tappings, ensuring accurate water level sensing and system response. By utilizing high-grade industrial materials, this fitting maintains pressure vessel integrity in high-demand hydronic environments. Whether you are performing routine maintenance or a full control overhaul, using the correct SA159-24 hook-up is essential for preventing leaks and ensuring the precise operation of boiler level safety devices across residential and commercial steam systems.

• Direct Compatibility: Engineered specifically for McDonnell & Miller 42A, 47, 64A, 67, and 42S-A Series units to ensure a perfect fit.
• Streamlined Installation: Designed for direct gauge glass tapping, reducing labor time and potential points of failure during the hook-up process.
• Industrial Grade Durability: Robust construction stands up to the thermal stresses and sediment common in steam heating systems.
• OEM Reliability: Ensures that the low water cut-off or water feeder functions according to factory performance specifications.

What is the difference between an upper and lower hook-up fitting?
The SA159-24 is the lower quick hook-up fitting. It is often paired with an upper fitting (such as the SA259-24) to complete the bypass loop required for many mechanical water feeders and cut-offs. Always verify which fitting has failed before ordering.

Can this fitting be used with other brands of low water cut-offs?
No, this part is specifically designed for McDonnell & Miller series controls. Using it on non-compatible brands may lead to incorrect water level readings or leaks.

Does this include the "Y" assembly or gaskets?
The 349500 is the fitting itself for the 24-inch configuration. It is recommended to inspect all blow-down valves and piping during replacement to ensure the entire assembly is free of blockage.

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.