PROTEUS INDUSTRIES FS115 Gpm Fluid Flow Switch Npt 1/2

( Brand: Proteus Industries ), ( Manufacturer Part Number: FS115 ), ( Part Type: Fluid Flow Switch ), ( Series: 100 Series ), ( Pcb Part Number: 200075 Rev C ), ( Product Type: Fluid Flow Switch With Electronic Control Module ), ( Preset Flow Rate: 3.0 Gpm ), ( Inlet Port Size: 1/2 Npt ), ( Max Pressure: 250 Psi ), ( Power Supply: 24 Vdc Or 120 Vac ), ( Relay Type: Spdt ), ( Relay Rating: 3a At 30 Vdc ), ( Sensor Technology: Paddlewheel / Hall-effect ), ( Trip Point Adjustment: 20-turn Recessed Potentiometer ), ( Connector Type: 4-pin Square ), ( Body Material: Aluminum Flow Body, Plastic Electronics Housing ), ( Serial Number: F 828966 ), ( Flow Direction: Labeled In And Out On Body ), ( Standards: Rohs Compliant )

Review PROTEUS INDUSTRIES Gpm Fluid Flow Switch 1/2 Inch Npt

The **Proteus FS115 115 GPM Fluid Flow Switch with 1/2 NPT Threading** is a high-performance, industrial-grade flow sensor designed to provide precise monitoring and control of liquid flow rates in demanding applications. Engineered for reliability and durability, this flow switch is ideal for use in HVAC systems, water treatment facilities, fire protection systems, and commercial or industrial plumbing where accurate flow detection is critical. Featuring a robust stainless steel construction, the FS115 is built to withstand harsh environments, including exposure to corrosive fluids, temperature fluctuations, and high-pressure conditions, ensuring long-term operational integrity. Its compact yet sturdy design allows for easy integration into existing piping systems, with a standard **1/2 NPT (National Pipe Thread) female connection** that ensures a secure and leak-proof fit.

At the heart of the FS115 is an advanced **turbine-based flow sensing mechanism**, which detects fluid velocity by measuring the rotational speed of a turbine impeller as the liquid passes through. This method provides a highly accurate and repeatable flow rate measurement, with a **sensing range of up to 115 gallons per minute (GPM)**, making it suitable for a wide variety of applications requiring moderate to high flow rates. The switch is equipped with a **configurable setpoint adjustment**, allowing operators to program the desired flow threshold whether for activation, deactivation, or alarm triggers via a simple and intuitive control interface. This flexibility ensures that the FS115 can be tailored to specific system requirements, whether for monitoring minimum flow conditions in a fire sprinkler system or ensuring optimal performance in a chilled water loop.

For enhanced safety and operational efficiency, the FS115 incorporates a **low-voltage, dry-contact relay output**, which can be wired into control panels, PLCs, or alarm systems to trigger actions such as pump activation, valve modulation, or fault alerts. The switch is designed to operate seamlessly with standard 120V or 24V control circuits, providing compatibility with most industrial automation setups. Additionally, its **IP65-rated enclosure** offers protection against dust, dirt, and splashing water, making it suitable for both indoor and outdoor installations where environmental resilience is essential. The FS115 also features a **backlit digital display**, allowing for easy on-site calibration and status verification, while its **self-diagnostic capabilities** help prevent downtime by alerting operators to potential issues before they escalate.

Beyond its technical specifications, the Proteus FS115 stands out for its **low-maintenance design**, requiring minimal upkeep to sustain optimal performance over extended periods. Its **non-intrusive installation** means that existing piping systems can be retrofitted without extensive modifications, reducing installation time and costs. Whether deployed in a commercial building s water distribution system, an industrial process line, or a critical infrastructure application, this flow switch delivers dependable performance with minimal operational overhead. With its blend of precision engineering, adaptability, and rugged construction, the Proteus FS115 is a versatile solution for professionals who demand both accuracy and reliability in fluid flow monitoring.

The **Proteus FS115** is a fluid flow switch designed for monitoring and controlling liquid flow rates in industrial, HVAC, and plumbing systems. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros of the Proteus FS115**

1. **High Flow Range and Accuracy**

The FS115 is rated for a flow range of **0 115 GPM (gallons per minute)** with a **1/2 NPT connection**, making it suitable for medium to large-scale applications. Its mechanical design ensures reliable detection of flow rates within its specified range, reducing false triggers.

2. **Durable Construction**

It is built with **stainless steel and brass components**, which enhances its resistance to corrosion, wear, and pressure fluctuations. This makes it ideal for use in harsh environments, such as industrial plants or water treatment systems.

3. **Adjustable Sensitivity**

The flow switch allows for **adjustable threshold settings**, enabling users to customize the flow rate at which the switch activates. This flexibility is useful in applications where flow rates may vary but need consistent monitoring.

4. **Wide Temperature and Pressure Ratings**

The FS115 operates effectively within a **temperature range of -20 F to 250 F (-29 C to 121 C)** and can handle **pressure ratings up to 150 PSI**, making it versatile for different fluid types (water, oil, glycol, etc.).

5. **Simple Installation and Maintenance**

With a **1/2 NPT threaded connection**, installation is straightforward for most plumbing or piping systems. It requires minimal maintenance, primarily involving periodic checks for debris or wear on the internal mechanism.

6. **Electrical Versatility**

The switch offers **multiple electrical configurations**, including **SPDT (Single Pole Double Throw)** and **NO/NC (Normally Open/Normally Closed)** options, allowing compatibility with various control systems and alarms.

7. **Cost-Effective for Medium-Duty Applications**

Compared to electronic flow sensors, the FS115 provides a **mechanical, low-maintenance alternative** at a relatively affordable price, making it a practical choice for budget-conscious projects.

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### **Cons of the Proteus FS115**

1. **Limited Flow Range for High-Volume Systems**

While the **0 115 GPM range** is suitable for many applications, it may be **too low for high-capacity industrial systems** (e.g., large HVAC units, fire suppression systems, or heavy machinery cooling loops). In such cases, a higher-range flow switch (e.g., 200 GPM) would be necessary.

2. **Mechanical Wear Over Time**

As a **mechanical flow switch**, it relies on moving parts (e.g., a rotating vane or impeller). Prolonged use in **abrasive or particulate-laden fluids** can lead to **wear and reduced accuracy**, requiring eventual replacement.

3. **No Digital Output or Communication**

Unlike electronic flow meters, the FS115 provides **only a simple electrical signal (SPDT)** without digital outputs (e.g., 4-20mA, Modbus, or pulse signals). This limits its integration with **smart control systems, data logging, or advanced automation**.

4. **Pressure Drop Considerations**

The switch introduces a **minor pressure drop** across the piping system due to its internal mechanism. While typically negligible in most applications, this could be a concern in **high-efficiency or low-head systems** where minimal resistance is critical.

5. **Limited Environmental Resistance**

While it handles **moderate temperatures and pressures**, extreme conditions (e.g., **highly corrosive fluids, freezing temperatures, or high-vibration environments**) may require additional protection or a more robust model.

6. **No Built-In Diagnostics**

Unlike some electronic sensors, the FS115 **does not provide self-diagnostic features** (e.g., fault codes or signal strength indicators). Troubleshooting may require manual inspection or replacement if it fails.

7. **Potential for False Triggers in Low-Flow Conditions**

In **very low-flow scenarios** (near the lower end of its range), the mechanical switch may be **less reliable** due to fluid turbulence or debris interfering with the sensing mechanism.

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### **Conclusion**

The **Proteus FS115** is a **reliable, cost-effective, and durable mechanical flow switch** well-suited for **medium-range flow monitoring (0 115 GPM)** in applications where simplicity, robustness, and low maintenance are priorities. It excels in **industrial, HVAC, and general plumbing systems** where electronic sensors may be overkill or impractical.

However, it is **not ideal for high-volume, high-precision, or smart-system applications** due to its **mechanical limitations, lack of digital outputs, and potential for wear**. Users should carefully consider their **flow requirements, environmental conditions, and integration needs** before selecting this switch.

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### **Recommendation**

- You need a **simple, mechanical flow switch** for **0 115 GPM applications**.

- Your system operates in **moderate temperature and pressure conditions** (up to 250 F/150 PSI).

- You prioritize **low cost, durability, and ease of installation/maintenance**.

- Your control system only requires a **basic SPDT or NO/NC signal**.

- Your application requires **higher flow rates (above 115 GPM)** opt for a **larger mechanical switch or an electronic flow meter**.

- You need **digital outputs, data logging, or smart system integration** choose an **electronic flow sensor (e.g., ultrasonic, turbine, or magnetic flow meter)**.

- Your fluid is **highly abrasive, corrosive, or contains debris** look for a **more rugged or filtered mechanical switch** (e.g., with a strainer).

- You require **high precision or low-pressure-drop performance** an **electronic flow meter** may be better suited.

For most **general-purpose, medium-flow applications**, the FS115 remains a **solid, practical choice** due to its balance of performance and affordability.

Details:

Technical Specifications, make Proteus Industries, part numberfs115 pcb: 2000 75 rev c, preset trip point 3.0 gpm adjustable via 20-turn pot, port size 1/2 npt in / out, max pressure250 psi, power supply 24 vdc or 120 vac, relay, 3a 30 vdc, connector 4-pin square male. Why Motion Constrained. Guaranteed Working. Ports are 1/2 NPT IN and OUT labeled, rated to 250 PSI, compatible with 24 VDC or 120 VAC power; trip point is field-adjustable via the recessed 20-turn potentiometer visible on PCB.

Guaranteed functional. A pelleting/crating fee may apply for very large items. We price aggressively and accept reasonable best offers. Used does not mean untested.

Changed your mind or it just does not work out. Where Do You Get All This Stuff. Priced to Move. FS115 All Photos 9 images thumbnail to view The Proteus Industries is a 100 Series fluid flow switch combining paddlewheel/Hall-Effect sensor body with an integrated electronic control module PCB 2000 75 Rev C.

LOCATION: C-1604-H.

part #: fs115 price

• $50.00

specifications pneumativalv:

• brand: Proteus Industries
• mpn: Fs115
• part type: Fluid Flow Switch
• series: 100 Series
• pcb part number: 200075 Rev C
• product type: Fluid Flow Switch With Electronic Control Module
• preset flow rate: 3.0 Gpm
• inlet port size: 1/2 Npt
• max pressure: 250 Psi
• power supply: 24 Vdc Or 120 Vac
• relay type: Spdt
• relay rating: 3a At 30 Vdc
• sensor technology: Paddlewheel / Hall-effect
• trip point adjustment: 20-turn Recessed Potentiometer
• connector type: 4-pin Square
• body material: Aluminum Flow Body, Plastic Electronics Housing
• serial number: F 828966
• flow direction: Labeled In And Out On Body
• standards: Rohs Compliant

payments pneumativalv:

• credit card: Mastercard
• other
• wallet: Apple-pay

seller pneumativalv:

• # reviews: 21660
• city: Laporte, Colorado
• rating: 100.0%

general pneumativalv:

• condition: Used
• Pump Flow Controllers > Flow Controllers Meters > Flow Meters

shipping pneumativalv:

• cost: $0.00
• transit: 3-8 Days
• class: Standard, One-day
• carrier: USPS, UPS
• type: Calculated
• service: USPS Ground Advantage, UPS Ground, UPS Next Day Air

offer pneumativalv:

• best offers: True
• quantity: 1
• started: May 19, 2026
• availability: In Stock
• options: Ship-to-home
• sold: 0

returns pneumativalv:

• policy: Returns Accepted
• method: Money back
• paid by: Seller
• time: 30 Days

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