McDonnell & Miller 27-W Control

The McDonnell & Miller 27-W is a robust, float-operated liquid level control specifically engineered for make-up water applications in open tanks and receivers. This mechanical water feeder features a high-capacity valve mechanism that responds to minimal float movement, ensuring a consistent liquid level in commercial and industrial systems. Built with a durable brass body, a Monel valve seat, and an EPDM disc, the 27-W is designed to handle demanding environments, supporting a maximum supply pressure of 100 psi and a maximum vessel operating pressure of 35 psi. The service-friendly 3/4" NPT threaded connections allow for straightforward integration into existing piping. Whether you are managing condensate receiving tanks or distillation equipment, this direct-mounted liquid level control provides the mechanical reliability needed to prevent low-water conditions and maintain system equilibrium without the need for complex electronic sensors.

Key Benefits for Contractors:

• Large Feeding Capacity: The high-flow valve opens fully with a minimal float drop, providing rapid response for large receiver tanks.
• Industrial Grade Materials: Features a Monel valve seat for superior erosion resistance and an EPDM disc for reliable sealing up to 212°F.
• Versatile Mounting Options: Can be flange-mounted externally on a receiver or installed internally to spill water directly into the tank.
• Direct Mechanical Action: Uses a cam-and-roller straight-thrust action with integral valve guides to ensure positive alignment and prevent sticking.

Common Questions:

What is the maximum temperature rating for the 27-W?
This control is rated for a liquid temperature range of 40°F to 212°F, making it suitable for both cold water make-up and hot condensate applications.

Can this be used on pressurized steam boilers?
No, the 27-W is designed strictly for open tank applications with a maximum vessel pressure of 35 psi. For high-pressure steam boiler water feeding, please consult our team for a compatible low-water cut-off or pump controller.

What maintenance is required for the float mechanism?
Technicians should perform a weekly blow-down of the tank (depending on water quality) to clear sediment. Periodically inspect the SA27W-6 valve assembly and 421-30 float for scale buildup to ensure unrestricted movement.

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.