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McDonnell & Miller FS7-4W Insertion-Style Flow Switch for Liquids - Insertion-Style Switches for Liquids
McDonnell & MillerInsertion-Style Switches for Liquids

McDonnell & Miller FS7-4W Insertion-Style Flow Switch for Liquids

The MCDONNELL & MILLER FS7-4W 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 rated…

SKU 3G-OTH-93930

Also listed as: FS74W · FS7 4W

Brand
McDonnell & Miller
Item
FS7-4W Insertion-Style Flow Switch for Liquids
Part Number
FS7-4W
Category
Insertion-Style Switches for Liquids
Available to Order
Also known as:FS7-4WMcDonnell & Miller
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
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Technical Specifications

McDonnell & Miller
Manufacturer Part Number
FS7-4W
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)
7.4 A @ 120V (Full Load)
Hazardous Location Rating
Class I, Div 1 and 2, Group C, D

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3G Electric (S) Pte. Ltd. — Singapore

Product Description

The MCDONNELL & MILLER FS7-4W 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 rated at 7.4 A @ 120V (Full Load). This switch carries a hazardous location rating of Class I, Div 1 and 2, Group C, D.

Frequently Asked Questions

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

The McDonnell & Miller FS7-4W 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 industrial process control, HVAC, and water treatment systems to protect pumps and equipment.

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

The FS7-4W has a brass body with a 1-1/4 in NPT connection, SPDT switch rated at 7.4 A @ 120V (Full Load), and a hazardous location rating of Class I, Div 1 and 2, Group C, D. It fits pipe sizes from 1-1/4 in to 16 in.

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

3G Electric supplies the McDonnell & Miller FS7-4W flow switch worldwide. As a global industrial solutions provider, we handle full logistics, customs clearance, and delivery to your site. Contact us for pricing and lead time on this item.

How to install a McDonnell & Miller paddle flow switch?

Install the FS7-4W in a horizontal pipe section with the paddle oriented against flow direction. Ensure the pipe is fully drained and the NPT connection is sealed with thread tape. Wire the SPDT switch per your control circuit, typically for pump start/stop or alarm.

Used in

Common applications for McDonnell & Miller
Boiler systems — McDonnell & Miller FS4-3T3-1 flow switch for low-water cutoff and pump protection in 1-inch piping.
Pump control — McDonnell & Miller FS8-W flow switch for detecting flow in 1-inch lines to prevent dry running.
HVAC cooling water — McDonnell & Miller FS6-3/4 flow switch for monitoring flow in 3/4-inch chilled water circuits.
Process piping — McDonnell & Miller FS5-3/4 brass flow switch for hot water applications up to 250°F.
Industrial liquid monitoring — McDonnell & Miller FS6-W-1 flow switch for 1-inch lines with high locked-rotor rating.
Small pipe systems — McDonnell & Miller FS-1 flow switch for 1/2-inch lines in liquid circuits requiring flow detection.
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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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