McDonnell & Miller 310451 Paddle Kit

Maintain precise flow detection with the McDonnell & Miller 310451 Paddle Kit, a critical replacement component designed for liquid flow switches. This stainless steel paddle kit, also identified by model number FS4-15SS, provides the necessary rigidity and corrosion resistance required for demanding hydronic and process cooling applications. It is engineered to provide a direct replacement for KIT21A-601 and PLT52A-600R, ensuring seamless mechanical compatibility with established system configurations. The kit contains four distinct paddles—specifically 1", 2", 3", and 6" lengths—allowing technicians to field-configure the switch for pipe sizes ranging from 1" to 8" NPT.

As a veteran's choice for HVAC flow switch parts, the 310451 is compatible with high-performance McDonnell & Miller FS4-3 series, FS8-W, and FS250 models. These paddles are constructed to withstand fluid temperatures up to 300°F and system pressures up to 160 psi, making them ideal for monitoring general purpose liquid flow. By utilizing 300-series stainless steel, this flow switch replacement paddle kit prevents premature failure due to oxidation or mineral buildup, ensuring the snap switch triggers accurately during proof-of-flow sequences for pumps, boilers, and chillers. Whether you are performing routine maintenance or a critical repair, this kit ensures the mechanical linkage remains responsive to current velocity requirements.

Key Benefits:

• Universal Pipe Compatibility: Includes 1", 2", 3", and 6" stainless steel paddles to accommodate diverse pipe diameters and flow velocities.
• Enhanced Durability: Rigid stainless steel construction resists cavitation and chemical degradation in aggressive fluid environments.
• Precision Fit: Specifically engineered as a replacement for PLT52A-600R and KIT21A-601 to eliminate field-modification errors.
• Broad Application: Suitable for all McDonnell & Miller FS4-3 models (excluding D and T variants) and high-capacity FS250 series switches.

Common Questions:

Can these paddles be used in corrosive liquid applications?
Yes, the 303/304 stainless steel construction is designed for compatibility with water and other non-hazardous liquids. For highly corrosive chemical processes, consult the specific flow switch body ratings.

Are the paddles trimmable for non-standard pipe sizes?
While the kit provides standard lengths for 1" through 8" piping, these rigid paddles are intended to be used as-is for maximum structural integrity. Proper selection of the included paddle lengths usually meets most installation requirements without modification.

Does this kit include the mounting screws?
This kit typically consists of the paddles themselves. It is recommended to retain the original 8/32" stainless steel screws or source direct OEM mounting hardware to ensure secure attachment to the paddle arm.

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.