McDonnell & Miller 310447 Valve

The McDonnell & Miller 310447, specifically the Model 14-B Blow Down Valve, is a high-performance full-port ball valve engineered for critical maintenance of hydronic heating systems. Designed as a direct replacement for McDonnell & Miller Series 47, 67, and 70B boiler controls, this 14-B valve facilitates the essential "blow down" procedure required to flush sediment and ensure the reliability of low water cut-off mechanisms. Featuring a 3/4" NPT connection and PTFE (Teflon) seats, it provides a bind-free, leak-tight seal even under repeated cycling in high-temperature environments. This boiler blow down replacement is rated for a maximum pressure of 30 psi and includes a high-visibility handle positioned to protect technicians from steam discharge. Using this genuine McDonnell & Miller part ensures strict adherence to original equipment tolerances and preserves boiler system efficiency by preventing sludge buildup that can compromise float operation and heat transfer.

• Precise Compatibility: Engineered specifically for Series 47, 67, 247, and 70B water feeders and low water cut-offs.
• Durable Construction: Features PTFE seats for a smooth, non-stick interface and high chemical resistance against typical boiler additives.
• Safety-Oriented Design: The easy-open handle is configured to keep the operator's hands away from hot water and steam during discharge.
• Full Flow-Path: The full-ported ball action minimizes pressure drop and ensures large debris particles are effectively flushed out.
• Complete Install Kit: Shipped with the necessary gasket and mounting screws to ensure a proper seal to the control body.

Is the 310447 Model 14-B compatible with the older spring-type valves?
Yes, the 14-B ball-type valve is the modern replacement for older spring-actuated blow-off valves used on the 47 and 67 series controls, providing a more reliable and easier-to-operate solution.

What is the recommended blow down frequency for this valve?
To maintain optimal sediment control and verify low water cut-off functionality, the valve should be operated weekly during the heating season or according to the boiler manufacturer's maintenance schedule.

Does the 310447 include the required mounting hardware?
Yes, the package includes the replacement gasket and the four mounting screws required for installation on the control's mating surface.

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.