1" Digital Water Flow Switch, 10-100L/min, NPN/ PNP

0 review(s) | Add your review

SKU: SUCH-FLS-NPF3W71110

$446.39

● 1 inch connection diameter ● 10-100 L/min rated flow range ● NPN/ PNP/ 4-20mA/1~5V ● 4-digit 7-segment 2-color LED

Output Signal *

Qty:

🚚 Free shipping

🕒 Delivery date: 6-12 days

🔁 30-day Returns

Overview
Specs
Application
FAQ
Reviews

Overview

The 1-inch digital water flow switch employs the Karman vortex street detection principle, suitable for flow monitoring of low-viscosity liquid media such as water and ethylene glycol solutions. With a measurement range of 10–100 L/min and a display range of 7–140 L/min, it provides real-time readings of instantaneous and cumulative flow rates. Equipped with a dual-sided LED digital display, it supports a minimum setting unit of 1 L/min, NPN/PNP open-collector output, and 4–20mA, 1–5V analog signal output. This facilitates easy integration with PLCs or automated control systems, making it widely applicable in industrial cooling water, equipment circulation water, and automated flow monitoring systems.

Feature

1 inch digital air flow switch feature

The 1-inch digital water flow switch features a rated flow range of 10–100 L/min, with a display and setting range extending to 7–140 L/min.
Its built-in dual-color LED digital display simultaneously shows instantaneous and cumulative flow data. The dual-sided display structure ensures easy data reading regardless of installation orientation, enhancing field operation convenience.
SUCH flow switches offer multiple output options: NPN/PNP switch outputs, 1–5V voltage signals, and 4–20mA analog signals for flow monitoring and automated control.
Supports upper/lower limit comparison mode, hysteresis mode, and cumulative pulse output mode. Features short-circuit protection and flexible alarm/control condition settings for enhanced system safety and stability.

Dimension (unit: mm)

Body Dimension

Digital water flow switch dimension

Basic Dimensions	A	AA	B	D	E	F	G	H
	124	92	46	77	57.6	23	41	42
	J	K	L	N	P	/	/	/
	63	48	28	18	Ø3.5 deep 14	/	/	/
Bracket Dimensions	S	T	U	V	W	WX	Y	Z
Bracket Dimensions	44	36	42	58	70	5.5	7	2

M8 Lead Wire Dimension

Digital water flow switch lead wire dimension

Detail

Digital water flow switch details

Function Panel: Enables switching between functions and rapid application response.
Water Sensor: Specifically designed to detect water flow and transmit data to the main board.
Main Board: Stores memory data, records data, and provides real-time display.

Pin Number & Wire Color

Digital water flow switch wire color

Pin Number	Content	Wire Colors
1	DC (+)	Brown
2	OUT 2	White
3	DC (-)	Blue
4	OUT 1	Black

Flow Rate Diagram

Digital water flow switch flow rate diagram

Output Type	A	B	C
Voltage Output	1 V	1.4 V	5 V
Current Output	4 mA	5.6 mA	20 mA

Specs

Connection Diameter Rc(PT)	1 inch
Measured Fluid	Water and ethylene glycol water solutions (viscosity ≤3 mPa·s / 3 cP)
Detection Method	Karman vortex street type
Rated Flow Range	10–100 L/min
Display Flow Range	7–140 L/min
Set Flow Range	7–140 L/min
Minimum Setting Unit	1 L/min
Cumulative Pulse Conversion Value	1 L/pulse
Operating Fluid Temperature	0–90°C (non-condensing)
Display Unit	Instantaneous flow L/min, cumulative flow L
Accuracy	Display value ±3% F.S., analog output ±3% F.S.
Repeatability	±2% F.S.
Temperature Characteristics	±5% F.S. (at 25°C reference)
Operating Pressure Range	0–1 MPa
Pressure Loss	45 kPa at max. flow (without flow control valve)
Cumulative Flow Range	99999999.9 L / per 1 L
Output Type	NPN or PNP open-collector output
Voltage Output	1–5 V (output impedance 1 kΩ)
Current Output	4–20 mA
Maximum Load Current	80 mA
Maximum Applied Voltage	DC 28 V
Internal Voltage Drop	NPN: ≤1 V (80 mA load) / PNP: ≤1.5 V (80mA load)
Response Time	0.5s / 1s / 2s
Output Protection	Short-circuit protection
Output Mode	Hysteresis mode, upper/lower limit comparison mode, cumulative output mode, cumulative pulse output mode
Load Impedance	DC12V: 300Ω
Load Impedance	DC24V: 600Ω
Hysteresis	Adjustable
External Input	No voltage input: ≤0.4V (with or without contact), input ≥30ms
Display Method	Dual-sided display
Display Screen	4-digit 7-segment 2-color LED
Operation Indicator	Output 1 / Output 2: Orange
Power Supply Voltage	DC12–24V ±10%
Current Consumption	≤50mA
Protection Rating	IP65
Operating Temperature Range	0–50°C (non-condensing)
Operating Humidity Range	35–85%RH (non-condensing)
Withstand Voltage	AC1000V 1 minute
Insulation Resistance	≥50MΩ (DC500V)
Wetted Parts Material	PPS / SUS304 / FKM / SCS13
Standards and Regulations	CE, UL(CSA), RoHS
Lubrication	Grease-free specification
Weight	1kg

Application

Central Air Conditioning System

Boiler Equipment

Water Purification Equipment

FAQ

Q1: How do I set an alarm or control thresholds for a digital water flow switch? ❯

Most digital water flow switches support configurable flow thresholds. Users can set minimum or maximum flow values via device buttons or control interfaces. When detected flow reaches or exceeds the set range, the device automatically outputs alarm or control signals—such as activating pumps, shutting down equipment, or triggering alarm systems. Properly setting control values effectively protects equipment and enhances system automation.

Q2: What is the service life of a digital water flow switch? ❯

The service life of a digital water flow switch typically depends on the operating environment, water quality conditions, and device quality. Under normal working conditions, high-quality products can reliably operate for millions of switching cycles. With clean water, stable pressure, and proper maintenance, the device's lifespan can often reach several years or longer. Therefore, selecting reliable products and performing regular maintenance is crucial.

Q3: How can I determine if a digital water flow switch is damaged? ❯

If the digital water flow switch exhibits abnormal displays, fails to output signals, or shows no response to flow changes, it may indicate a malfunction. First, inspect the power supply, cable connections, and check for pipe blockages. If these conditions are normal but the issue persists, internal sensors or circuitry may be damaged, requiring repair or replacement. Prompt detection and resolution of faults prevent disruption to system operations.

0 review(s)

Write your own review Close

Review title: *

Review text: *

Rating:

1 2 3 4 5

1" Digital Water Flow Switch, 10-100L/min, NPN/ PNP

Feature

Dimension (unit: mm)

Detail

Pin Number & Wire Color

Flow Rate Diagram

Central Air Conditioning System

Boiler Equipment

Water Purification Equipment

3/8" Digital Water Flow Switch, NPN/ PNP/ 4-20mA/1~5V

1/2" Digital Water Flow Switch, 2-16L/min, NPN/ PNP

3/4" Digital Water Flow Switch, 5-40L/min, NPN/ PNP

Brass Water Flow Switch, 1-30 L/min, 1-50 L/min

3/8" Digital Air Flow Switch, NPN/ PNP 2 Output

1/2" Digital Air Flow Switch, NPN/ PNP 2 Output