Dollar for dollar, sight flow indicators are the most cost efficient and effective way to visually monitor the flow of fluids and to determine where, if any, problems exist at certain points along the industrial process line. OPW has been manufacturing sight flow indicators for over 60 years. Our experience has led to many innovations in design and manufacturing, making VISI-FLO® the most thoroughly-engineered Sight Flow Indicator on the market. VISI-FLO’s are available in two series: the Standard 1400 Series, and the 1500 High-Pressure High-Temperature Series.

Standard Features 
Exclusive 3-Year “No-Leak” Guarantee
 – VISI-FLO’s innovative radial seal creates a constant and uninterrupted sealing force between the body and outside diameter of the glass lens. This sealing method provides a longer lasting and better seal than conventional flat seals. 

Maintenance-Free Design – VISI-FLO’s unique, bolt-on-body design requires no special maintenance or torquing sequence be followed to prevent leaks. This results in a safer, more reliable sight flow indicator than those units using tie rods to fasten lens and seal to body. 
Dimensionally Interchangeable – “FJP” Flanged VISI-FLO®s feature end-to-end dimensions that match Jacoby-Tarbox and Penberthy and other manufacturers’ units. “FJP” units are available in 3/4", 2", 3", and 4".