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Mcdonnell & Miller Series 767 – Low Water Cut-Offs - Low Water Cut Offs
Mcdonnell & MillerLow Water Cut Offs

Mcdonnell & Miller Series 767 – Low Water Cut-Offs

Note: listed by manufacturer as obsolete/discontinued.

SKU 3G-OTH-02746

Brand
Mcdonnell & Miller
Item
Series 767 – Low Water Cut-Offs
Category
Low Water Cut Offs
Available to Order
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Delivery
Same-day or next-business-day delivery within Singapore for in-stock items; 7–14 days for factory-order parts from Europe.
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.
Ships to
Singapore

Technical Documents

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

Product Description

Note: listed by manufacturer as obsolete/discontinued.

Frequently Asked Questions

What is the McDonnell & Miller 21 low water cut-off used for?

The McDonnell & Miller 21 is a low water cut-off used on steam and hot water boilers to shut down the burner if water level drops below safe limits. It features a lever-operated full port ball valve for blow down and an adjustable BX outlet for wiring.

What are the specifications of the McDonnell & Miller 21 low water cut-off?

The McDonnell & Miller 21 has a 2-inch NPT body tapping for side mounting on boilers. It includes a lever-operated full port ball valve for blow down and an adjustable BX outlet. Note: the manufacturer lists this model as obsolete/discontinued.

Where to buy the McDonnell & Miller 21 in Singapore?

3G Electric supplies the McDonnell & Miller 21 low water cut-off to Singapore. We source and deliver this item, handling logistics and customs clearance. Contact us for availability and lead time.

How to install the McDonnell & Miller 21 low water cut-off?

Install the McDonnell & Miller 21 by mounting it on the boiler side using the 2-inch NPT tapping. Ensure the blow-down valve is accessible for periodic maintenance. Wire the adjustable BX outlet per local codes. Always follow the manufacturer's instructions for safe operation.

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

Mcdonnell & Miller Products

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

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Compatible alternatives & equivalents

Cross-referenced by specification & description
This 2-way ball valve is designed for use in HVAC systems to control the flow of water-glycol solution up to 50%. It features a 1/2 in Female NPT connection, 0.4 CV flow coefficient, and 200 psi close-off rating. Constructed with a stainless steel ball and brass body, this valve is supplied without an actuator for integration with compatible actuators in hydronic heating and cooling loops
HVAC
This 2-way ball valve is designed for use in HVAC systems to control the flow of water-glycol solution up to 50%. It features a 1/2 in Female NPT connection, 0.4 CV flow coefficient, and 200 psi close-off rating. Constructed with a stainless steel ball and brass body, this valve is supplied without an actuator for integration with compatible actuators in hydronic heating and cooling loops
This 2-way ball valve is designed for use in HVAC systems to control the flow of water-glycol solution up to 50%. It features a 1/2 in Female NPT connection, 0.63 CV flow coefficient, and 200 psi close-off rating. The valve is constructed with a stainless steel ball and brass body, and is supplied without an actuator for separate selection
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This 2-way ball valve is designed for use in HVAC systems to control the flow of water-glycol solution up to 50%. It features a 1/2 in Female NPT connection, 0.63 CV flow coefficient, and 200 psi close-off rating. The valve is constructed with a stainless steel ball and brass body, and is supplied without an actuator for separate selection
2-way ball valve with 1/2 in female NPT connections, designed for water media in hydronic systems. Features a stainless steel ball and brass body, with 1 CV flow and 200 psi close-off. Supplied without actuator
HVAC
2-way ball valve with 1/2 in female NPT connections, designed for water media in hydronic systems. Features a stainless steel ball and brass body, with 1 CV flow and 200 psi close-off. Supplied without actuator
This 2-way ball valve is designed for water media in hydronic HVAC systems. It features a stainless steel ball and brass body with a 3/4 in Female NPT connection. The valve has a CV flow of 6.3 and a close-off rating of 200 psi. It is supplied without an actuator for field installation
HVAC
This 2-way ball valve is designed for water media in hydronic HVAC systems. It features a stainless steel ball and brass body with a 3/4 in Female NPT connection. The valve has a CV flow of 6.3 and a close-off rating of 200 psi. It is supplied without an actuator for field installation
This 2-way ball valve features a 1 in female NPT connection, 10 CV flow rating, and 200 psi close-off. Constructed with a stainless steel ball and brass body, it is designed for water media in hydronic systems. Supplied without an actuator
HVAC
This 2-way ball valve features a 1 in female NPT connection, 10 CV flow rating, and 200 psi close-off. Constructed with a stainless steel ball and brass body, it is designed for water media in hydronic systems. Supplied without an actuator
This 2-way ball valve features a stainless steel ball and brass body with 2 in Female NPT connections. It has a flow coefficient of 40 CV and a close-off pressure of 200 psi, designed for use with water-glycol solutions up to 50%. Supplied without actuator, it is suitable for on-off or modulating flow control in hydronic heating and cooling systems
HVAC
This 2-way ball valve features a stainless steel ball and brass body with 2 in Female NPT connections. It has a flow coefficient of 40 CV and a close-off pressure of 200 psi, designed for use with water-glycol solutions up to 50%. Supplied without actuator, it is suitable for on-off or modulating flow control in hydronic heating and cooling systems

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