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McDonnell & Miller FS7-4S Paddle-Type Insertion Flow Switch for Liquids - Insertion-Style Switches for Liquids
McDonnell & MillerInsertion-Style Switches for Liquids

McDonnell & Miller FS7-4S Paddle-Type Insertion Flow Switch for Liquids

The MCDONNELL & MILLER FS7-4S is a paddle-type insertion-style flow switch for liquids, designed for pipe sizes from 1-1/4 in to 16 in. It features a brass body with a 1-1/4 in NPT connection and an SPDT switch. The…

SKU 3G-OTH-93898

Also listed as: FS74S · FS7 4S

Brand
McDonnell & Miller
Item
FS7-4S Paddle-Type Insertion Flow Switch for Liquids
Part Number
FS7-4S
Category
Insertion-Style Switches for Liquids
Available to Order
Also known as:FS7-4SMcDonnell & Miller
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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 Specifications

McDonnell & Miller
Manufacturer Part Number
FS7-4S
Type
1 1/4 in/16 in For Pipe Size, Brass, NPT, SPDT
NPT
1 1/4 in
For Pipe Size
1-1/4 in
Contact Rating (AC)
22.2 A @ 240V (Locked Rotor)

Technical Documents

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

Product Description

The MCDONNELL & MILLER FS7-4S is a paddle-type insertion-style flow switch for liquids, designed for pipe sizes from 1-1/4 in to 16 in. It features a brass body with a 1-1/4 in NPT connection and an SPDT switch. The contact rating is 22.2 A at 240V (locked rotor).

Frequently Asked Questions

What is the McDonnell & Miller FS7-4S flow switch used for?

The McDonnell & Miller FS7-4S is a paddle-type insertion flow switch for liquids. It detects flow or no-flow conditions in pipes from 1-1/4 in to 16 in, commonly used in HVAC, boiler, and industrial water systems to protect pumps and equipment.

What are the specifications of the McDonnell & Miller FS7-4S?

The FS7-4S has a brass body with a 1-1/4 in NPT connection and an SPDT switch. It handles pipe sizes from 1-1/4 in to 16 in. Its AC contact rating is 22.2 A at 240V (locked rotor). The manufacturer part number is FS7-4S.

Where to buy the McDonnell & Miller FS7-4S worldwide?

3G Electric supplies the McDonnell & Miller FS7-4S flow switch worldwide. As a global industrial distributor, we handle full logistics, customs clearance, and delivery to your site. Contact us for availability and lead time.

How to install the McDonnell & Miller FS7-4S flow switch?

Install the FS7-4S by inserting the paddle into the pipe through a 1-1/4 in NPT fitting. Ensure the flow direction arrow on the body aligns with actual flow. Wire the SPDT switch per your control circuit. Always follow local codes and the manufacturer's manual.

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 insertion-style switches for liquids. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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