Series-SFI-700

Supported Applications

The Dwyer Series SFI-700 Visual Flow Indicators are designed to show the presence and direction of flow in a process line. These sight indicators feature glass tube construction with an easy-to-view bright red Acetal rotating impeller, allowing for 360° visibility from any angle. The series is specified for use with compatible gases and liquids, including water, air, and oil.

Operating Conditions & Performance

The Series SFI-700 operates within a process temperature limit of 212°F (100°C) and supports pressure ratings up to 230 psig (15.86 bar). Flow indication is achieved via impeller rotation, with minimum flow thresholds varying by size:

• Water Minimum Flows: Ranges from 0.10 GPM for 1/4 and 3/8 inch sizes to 1.0 GPM for the 1-1/2 inch size.
• Air Minimum Flows: Ranges from 1.1 SCFM for 1/4 and 3/8 inch sizes to 5.0 SCFM for 1-1/4 and 1-1/2 inch sizes.

The device includes internal wipers that clean the glass axially, restoring full visibility by rotating the tube without disrupting flow.

Dimensions by Size Grouping

• 1/4 & 3/8 inch: Length (L) 2-3/4 in (70 mm); Height (H) 1-1/2 in (38 mm).
• 1/2 & 3/4 inch: Length (L) 3-11/16 in (94 mm); Height (H) 2-1/4 in (57 mm).
• 1, 1-1/4 & 1-1/2 inch: Length (L) 4-7/8 in (124 mm); Height (H) 2-3/4 in (70 mm).

Configuration Options

The Series SFI-700 is available with threaded connections, including female NPT as standard. The series supports BSPP or BSPT metric thread forms via specific options. Body materials are offered in nickel-plated brass (Model 700) and 316 Stainless Steel (Model 700 SS). Wetted parts include a tempered borosilicate glass tube, fluoroelastomer gaskets, an Acetal impeller, and a 416 stainless steel spindle.

Additional configuration options documented for the series include:

• Bidirectional flow models
• Less impeller configurations
• BSPP or BSPT thread forms

Key Product Differences

The primary distinction within this series is the body material. The standard Model 700 features a nickel-plated brass body, while the SFI-700SS variant utilizes a 316 Stainless Steel body to accommodate different service requirements. Both variants share the same glass tube construction and red Acetal impeller design.

Connection options differentiate further; standard models utilize female NPT threads, whereas BSPP or BSPT thread forms are available as specific configuration choices for metric applications.