McDonnell & Miller 339700 Basket Assembly

The McDonnell & Miller 339700 (Model SA21-38R) is a critical strainer basket assembly engineered for high-performance integration with Series 21 Make-Up Water Feeders. As a veteran-grade replacement part, this assembly is vital for maintaining the filtration integrity of boiler systems, effectively trapping sediment and pipe scale before they can foul delicate valve seats or internal float mechanisms. This industrial-strength HVAC strainer is also compatible with Model 25A, Series 221, and Series 551S units, providing a versatile solution for contractors managing diverse water feeder portfolios.

Constructed for demanding hydronic environments, the McDonnell & Miller SA21-38R includes a precision-manufactured basket and a Tetraseal O-ring to ensure a leak-proof seal during the reassembly process. Regular inspection and replacement of the 339700 strainer assembly are essential boiler maintenance steps to prevent clogging and downstream component damage. By utilizing high-quality materials resistant to the corrosive effects of treated boiler water, this assembly supports long-term system reliability and stable water level control.

• Ensures peak performance of Series 21 and 25A make-up water feeders.
• Includes the necessary Tetraseal O-ring for a simplified, secure installation.
• Protects internal feeder components from abrasive debris and mineral build-up.
• Interchangeable across multiple McDonnell & Miller feeder series for reduced inventory overhead.
• Robust basket mesh provides superior filtration without causing significant pressure drops.

Is the O-ring included with the 339700 basket assembly?
Yes, the SA21-38R includes the specialized Tetraseal O-ring required to achieve a proper seal on the strainer housing.

Which water feeders are compatible with this strainer?
This strainer basket is specifically designed for use with McDonnell & Miller Series 21, 25A, 221, and 551S feeders.

When should I replace the strainer basket?
Technicians should inspect the basket during annual maintenance. If the mesh is torn or significantly corroded, replacement is necessary to protect the feeder’s valve assembly.

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.