McDonnell & MillerInline Switches for Liquids

MCDONNELL & MILLER Flow Switch: 3/4 in For Pipe Size, 3/4 in NPT, 3/4 in Connection Size

The MCDONNELL & MILLER FS6-W-3/4 is an inline flow switch for liquids designed for a 3/4 in pipe size with a 3/4 in NPT connection. It features a SPDT switch with a contact rating of 3.7 A @ 240V (Full Load).

SKU 3G-OTH-88502

Also listed as: FS6W34 · FS6 W 3 4 · FS6-W-3-4

Brand

McDonnell & Miller

Item

Flow Switch: 3/4 in For Pipe Size, 3/4 in NPT, 3/4 in Connection Size

Local availability & support

Delivery: Worldwide DHL shipping from Singapore; 7–14 business days door-to-door for most destinations.
Payment: Invoicing in USD. Bank transfer (SWIFT) and corporate PO accepted.

Technical Specifications

McDonnell & Miller

Manufacturer Part Number

FS6-W-3/4 

Type

NPT, SPDT 

NPT

3/4 in 

For Pipe Size

3/4 in 

Connection Size

3/4 in 

Contact Rating (AC)

3.7 A @ 240V (Full Load) 

Technical Documents

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McDonnell & Miller Products

3G Electric (S) Pte. Ltd. — Singapore

Product Description

Frequently Asked Questions

What is the MCDONNELL & MILLER FS6-W-3/4 flow switch used for?

The MCDONNELL & MILLER FS6-W-3/4 is an inline flow switch for liquids that detects flow or no-flow conditions in a 3/4 in pipe. It is commonly used in HVAC, boiler, and industrial process systems to protect equipment by activating alarms or shutting down pumps when flow is lost.

What are the specifications of the MCDONNELL & MILLER FS6-W-3/4?

The MCDONNELL & MILLER FS6-W-3/4 is designed for a 3/4 in pipe size with a 3/4 in NPT connection. It features a SPDT switch with a contact rating of 3.7 A @ 240V (Full Load). The manufacturer part number is FS6-W-3/4.

Where to buy the MCDONNELL & MILLER FS6-W-3/4 worldwide?

You can source the MCDONNELL & MILLER FS6-W-3/4 flow switch through 3G Electric, a global industrial equipment distributor. We handle full logistics, customs clearance, and delivery to worldwide destinations. Contact us for availability and lead time.

How to install the MCDONNELL & MILLER FS6-W-3/4 flow switch?

Install the MCDONNELL & MILLER FS6-W-3/4 in a horizontal pipe section with the flow arrow aligned to flow direction. Use thread sealant on the 3/4 in NPT connection and wire the SPDT switch per your control circuit. Always follow local codes and the manufacturer's instructions.

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 inline 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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