Dwyer SFI-300-1/2 Sight Flow Indicator 1/2 Inch Npt

Product Description

The DWYER SFI-300-1/2 is a bronze body sight flow indicator designed to provide visual confirmation of fluid or gas movement in a piping system. The 1/2 inch NPT threaded connection makes it compatible with standard trade piping configurations. Rated to 125 psi working pressure and 200 degrees F, this indicator is built for demanding environments including hydraulic lines, oil reservoirs, coolant tanks, and pressure vessels. The glass window allows direct visual inspection of flow without interrupting the line. Licensed plumbers, HVAC technicians, and industrial pipe fitters commonly install this component during system commissioning or maintenance upgrades.

The SFI-300-1/2 is suited for both residential and light commercial applications where visual flow verification is required. It supports both horizontal and vertical mounting orientations, giving installers flexibility in tight mechanical spaces. Rated for use with liquids and gases, it sees common use in coolant tanks, hydraulic tanks, oil reservoirs, and pressure vessels. The Buna-N seal material provides reliable service with petroleum-based fluids and many common coolants. At 4-1/16 inches overall length, the unit fits neatly into compact inline installations.

Key Features

• Bronze body construction rated for 125 psi maximum working pressure
• Glass window provides direct visual flow inspection without line interruption
• 1/2 inch NPT threaded connection for standard trade piping compatibility
• Supports both horizontal and vertical mounting orientations
• Buna-N seal material compatible with gas, oil, and liquid service
• Removable window design simplifies field inspection and maintenance

Compatibility

Designed as an OEM-style replacement or new-installation sight flow indicator for 1/2 inch NPT piping systems handling gas or liquid service, including coolant tanks, hydraulic lines, hydraulic tanks, oil reservoirs, and pressure vessels.

Installation Notes

Installation should be performed by a licensed plumber or qualified pipe fitter in accordance with applicable local codes and IPC guidelines. Depressurize and isolate the line completely before installing or servicing this indicator. Apply thread sealant or PTFE tape to the NPT threads per standard practice and tighten to hand-tight plus wrench-tight without over-torquing the bronze fittings. Confirm flow direction and mounting orientation before final tightening.