SFI-100-3/4 Visual Sight Flow Indicator | Inline Water Flow Verification

SFI-100-3/4 Visual Sight Flow Indicator

Reliable visual confirmation of flow in water and fluid systems

The SFI-100-3/4 Visual Sight Flow Indicator provides a simple, dependable way to verify that water or other compatible liquids are flowing through your system. By using a clearly visible rotating impeller behind a tempered glass window, this inline flow indicator allows operators and technicians to instantly confirm flow—without gauges, sensors, or power.

This visual flow indicator is ideal for applications where confirmation of movement is critical but precise flow measurement is not required. Common uses include water filtration systems, shot feeders, bypass feeders, corrosion coupon racks, coolant loops, and general process piping.

Designed for durability and long service life, the SFI-100-3/4 features a rugged bronze body with threaded connections and a compact footprint that installs easily into existing piping runs.

How it works

As fluid flows through the indicator, the internal impeller rotates, providing immediate visual confirmation through the glass viewing window. If flow stops or becomes restricted, the impeller slows or stops—making troubleshooting fast and intuitive.

Key features and benefits

• Instant visual verification of flow—no calibration required
• Rotating impeller provides clear indication even at low flow rates
• Single tempered glass window for durability and safety
• Compact inline design for tight installations
• Removable window design allows easy service and maintenance
• Works in both horizontal and vertical pipe orientations
• Economical protection for pumps, filters, and downstream equipment

Typical applications

• Water filters and treatment systems
• Shot feeders and chemical by-pass feeders
• Corrosion coupon racks
• Cooling water and heat exchanger loops
• Hydraulic and process fluid lines
• Pressure vessels and tanks

Technical specifications (SFI-100 series)

• Connection size: 3/4" threaded
• Service: Compatible liquids and gases
• Body material: Bronze
• Window: Tempered glass
• Indicator: Rotating impeller
• Maximum pressure: 125 PSIG
• Maximum temperature: 200°F (93°C)
• Mounting orientation: Horizontal or vertical
• Connections: Threaded process connections

These specifications ensure dependable performance in most commercial, industrial, and municipal water systems

Why choose a visual sight flow indicator?

Unlike electronic flow switches or meters, a visual sight flow indicator gives immediate, fail-safe confirmation that fluid is actually moving. There are no sensors to wire, no electronics to fail, and no false readings—just clear, direct confirmation that your system is doing what it should.