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3G Electric
Mcdonnell & Miller Series 21/221 Make-Up Water Feeders
Mcdonnell & MillerWater Feeders

Mcdonnell & Miller Series 21/221 Make-Up Water Feeders

McDonnell & Miller Water Feeders.

SKU 3G-OTH-02728

Also listed as: 21221 · 21 221 · 21-221

Brand
Mcdonnell & Miller
Item
Series 21/221 Make-Up Water Feeders
Part Number
21/221
Category
Water Feeders
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Worldwide DHL shipping from Singapore; 7–14 business days door-to-door for most destinations.
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Invoicing in USD. Bank transfer (SWIFT) and corporate PO accepted.

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Mcdonnell & Miller Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

McDonnell & Miller Water Feeders.

Frequently Asked Questions

What is the McDonnell & Miller 21/221 water feeder used for?

The McDonnell & Miller 21/221 water feeder is designed for boiler receiver tanks to automatically maintain proper water levels. Its direct mounting eliminates the need for equalizing connections, and the proportional feed action ensures precise water addition, making it ideal for commercial and industrial steam boiler systems.

What are the specifications of the McDonnell & Miller 21/221 water feeder?

The McDonnell & Miller 21/221 water feeder features a mounting flange with six 7/16-inch bolt holes for direct installation on boiler receiver tanks. It provides proportional feed action to regulate water flow without requiring equalizing connections. For detailed technical specifications, consult the manufacturer's datasheet.

Where to buy the McDonnell & Miller 21/221 water feeder in Singapore?

You can source the McDonnell & Miller 21/221 water feeder through 3G Electric in Singapore. We handle logistics, customs clearance, and delivery to your facility. Contact our team for a quotation and lead time on this boiler component.

How to install the McDonnell & Miller 21/221 water feeder?

Install the McDonnell & Miller 21/221 water feeder by bolting its flange directly to the boiler receiver tank using the six 7/16-inch bolt holes. Ensure the tank opening matches the flange pattern. No equalizing connections are needed. Follow standard boiler safety procedures and consult a qualified technician for proper setup.

Used in

Common applications for Mcdonnell & Miller
Steam boiler low-water cutoff — McDonnell & Miller inline flow switches (e.g., FS-1) for automatic burner shutdown
Cooling water flow monitoring — McDonnell & Miller insertion-style switches (e.g., FS4-3D) in large-diameter pipes
Hazardous-area process lines — McDonnell & Miller FS7-4E with NEMA 7/9 enclosure for Class I, Div 1 locations
HVAC chilled water systems — McDonnell & Miller FS6-1 inline switch for pump flow verification
Industrial wastewater treatment — McDonnell & Miller FS4-3S stainless steel switch for corrosive fluid flow detection
Boiler feedwater control — McDonnell & Miller FS8-WJ with BSP connections for international installations
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Mcdonnell & Miller Products

3G Electric supplies Mcdonnell & Miller water feeders. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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