McDonnell & Miller 328100 Replacement Casting

The McDonnell & Miller 328100 is an authentic OEM replacement casting specifically engineered for the 157-R Series low water cut-off and pump controllers. This heavy-duty 157-R casting provides the structural foundation for your float chamber, ensuring a pressure-tight seal in high-demand residential, commercial, and industrial steam boiler applications. In the field, these castings are critical for maintaining system integrity when original housings show signs of bypass leakage or significant scale pitting that compromises the boiler liquid level control mechanism.

Designed to handle a maximum operating pressure of 150 PSI, this component is precision-machined to accommodate standard 1-inch NPT equalizing tappings and the alternate tappings characteristic of the 157-R sub-series. When performing a boiler control maintenance overhaul, professionals rely on this genuine McDonnell & Miller part to restore the precise clearances required for Monel bellows and snap-action switch assemblies. Using this exact replacement casting for 157-R series ensures seamless compatibility with existing head mechanisms, preventing the nuisance burner shutdowns often caused by misaligned aftermarket housings.

• Verified OEM Compatibility: Purpose-built for the 157-R Series to ensure correct alignment of internal float linkages and bellows assemblies.
• Industrial-Grade Casting: Robust construction designed to withstand thermal cycling and high-pressure steam environments up to 150 PSI.
• Precision Tappings: Includes necessary ports for equalizing lines and gauge glass installations, maintaining standard NPT thread specifications.
• System Reliability: Essential for low water cut-off repairs where the integrity of the float chamber is compromised by corrosion or sediment buildup.

Does this casting include the head mechanism or switches?
No, the 328100 is the replacement body casting only. The head mechanism, bellows, and switches must be transferred from the existing unit or purchased separately.

Can this be used on standard 157 models without the 'R' designation?
The 157-R casting features specific alternate tapping configurations. It is highly recommended to verify your specific model's tapping layout to ensure the ports align with your current piping before installation.

What maintenance is required for this component?
Technicians should perform daily blow-downs on high-pressure systems and an annual internal inspection to clear sediment or sludge that can accumulate within the casting chamber.

This item is not eligible for free shipping.

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.