TELEFLO® 816BC-3/4

The Kaydon Model 816BC is a simple and uncomplicated variable area (flap type) flow indicator with an integral mechanical switch.   The 816BC flow switch operates with a spring and flap assembly that swings open as more flow enters the flow switch. The 816BC flow switches can be installed in any flow direction position, and straight pipe runs entering or exiting the flow switch is not required. The shaft assembly connection from the spring/flap assembly is affixed to a red “flow indicator” pointer to provide estimated flow indication against a numberless indicator scale.  Also, the shaft assembly is additionally fastened to a cam to activate a low flow condition switch.

The 816BC flow switches are designed for a wide range of oil and water flow applications.  These applications include:

Bearing Circulating Lube Oils

Gear Box Circulation Lube Oils

Cooling Water Lines

Seal Water Lines

Machine Tool Coolants Lines 


Size (inches)
3.8 L x 3.5 W x 3.4 H 
Inlet Connection
3/4 inch NPT 
Outlet Connection
3/4 inch NPT 
Material of Construction
Material of Construction
Shaft O-Ring Seal - Viton®
Head Gasket - Klingersil C-4401
Single Pole Double Throw (SPDT)
15A - 125VAC / 7A - 250 VAC / 3.5A - 480 VAC
1/2A - 125 VDC / 1/4A - 250VAC
UL Code L96
Frequency: 50 Hz / 60 Hz
Switch Actuator Type: Flexible Leaf
Three Terminals: 1 N.O. / 1 N.C. / 1 COM
(terminals are side facing with #8 screws)
Conduit Connection = 1/2 inch NPT
Switch Set Point
(factory set)
ISO 32 Oil = 4.5 gpm (approximate)
Water = 8 gpm (approximate)
Viscosity Range
Water (ISO 1) - Oil (ISO 460)
Flow Rate Indication Range (approximate)  Low Flow Point = 4 gpm (oil) - {based on ISO 32 oil}
Low Flow Point = 7 gpm (water) 
High Flow Point = 32 gpm (oil or water)
Application Notes Switch is preset at factory to serve as a "low flow" indicator for a low fluid flow condition.

Minimum flow to indicate flow:
(not for use below these flow rates)
4 gpm (oil) / 7 gpm (water)

816BC flow switches are flow indicators, not meters. 
Actual flow rate is not indicated on numberless dial scale.
Enclosure Rating NEMA 4 (moisture proof and dust proof)
Maximum Allowable Operating Pressure 125 psig at 150F fluid temperature (8.7 bar at 65C)
Operating Ambient Temperature Range -10F to 120F (-23C to 49C)

Ordering Information

Model Number: 816BC-3/4"
Part Number: 51B05