The KENCO NFS is designed to protect the compressor or engine cylinder against lubrication failure.
KENCO No-Flow Switches mount in the line between the lubricator and cylinder. On start-up, the first stroke of the lubricator automatically opens the “NFS” switch contact. The contact is opened and closed by the precision-fit plunger inside the “NFS” body. Lubricator oil flows through the body with the rate of flow controlled by the amount of oil that passes between the precision-fit plunger and the bore inside the body. If the lubricator stops pumping, the precision-fit plunger will drift back against the switch contact and stop the engine. The time interval between lubrication failure and shutdown can be adjusted by increasing or decreasing the compression on the precision-fit plunger spring.
The “NFS” is available with an overpressure rupture assembly which will instantaneously bleed off and stop the engine in the event where the lube line check valve plugs
The standard rupture disc fails at 1750 psi (11.72 bar). Other rupture-pressure options available upon request. The versions utilizing a switch terminal without a conduit connection have a maximum recommended working pressure of 2,000 psi (137.89 bar). The versions utilizing a switch with 1/2″ terminal connections have a maximum recommended working pressure of 4,000 psi (275.79 bar). The standard no-flow switch is supplied with a standard spring for lubricator pump rates of 6 drops per minute or more. Optionally, a light-spring model is available for lubricator pump rates less than 6 drops per minute and greater than 3 drops per minute.
* Ordering Note: Add “L” to the end of the Model Number for light spring
* (For Lubricator Pump Rates Less than 6 drops per minute and greater than 3 drops per minute)