NFS No-Flow Safety Switch
No-Flow Safety Switch
The KENCO NFS is designed to protect the compressor or engine cylinder against lubrication failure.
Operating Principle
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
Features
- Fail-Safe wear pattern. No dangerous “shoulder” to prevent shutdown so that switch is always functional with clean oil above its pour point.
- Shutdown time adjustable over a wide range
- Overpressure rupture assembly optional
- Low flow-rate option available
- Switch contact rating – 2A at 30 VAC or VDC
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.
Gallery
Specifications
Materials of Construction
- Body – Aluminum
- Seal Material – Buna-N
- Spring – Stainless Steel
Standard Model Options
- NFS-3= Switch terminal without conduit connection; no mounting bracket
- NFS-4= Switch terminal without conduit connection; mounting bracket for Ajax
- NFS-5= Switch terminal without conduit connection; mounting bracket for large Ajax (3 switches on 1 bracket)
- NFS-6= Switch terminal with 1/2″ NPT conduit connection; no mounting bracket
- NFS-7= Switch terminal without conduit connection; no mounting bracket; overpressure rupture assembly
- NFS-9= Switch terminal without conduit connection; mounting bracket for Ajax; overpressure rupture assembly
- NFS-11= Switch terminal with 1/2″ NPT conduit connection; no mounting bracket; no inlet our outlet tubing connectors
- NFS-25= Switch terminal with 1/2″ NPT conduit connection; no mounting bracket; overpressure rupture assembly
- NFS-30= Switch terminal without conduit connection; no mounting bracket; 90° inlet and outlet tubing connections
* Ordering Note: Add “L” to the end of the Model Number for light spring
Light-Spring Model Options
- NFS-3L= Switch terminal without conduit connection; no mounting bracket
- NFS-4L= Switch terminal without conduit connection; mounting bracket for Ajax
- NFS-5L= Switch terminal without conduit connection; mounting bracket for large Ajax (3 switches on 1 bracket)
- NFS-6L= Switch terminal with 1/2″ NPT conduit connection; no mounting bracket
- NFS-7L= Switch terminal without conduit connection; no mounting bracket; overpressure rupture assembly
- NFS-9L= Switch terminal without conduit connection; mounting bracket for Ajax; overpressure rupture assembly
- NFS-11L= Switch terminal with 1/2″ NPT conduit connection; no mounting bracket; no inlet our outlet tubing connectors
- NFS-25L= Switch terminal with 1/2″ NPT conduit connection; no mounting bracket; overpressure rupture assembly
- NFS-30L= Switch terminal without conduit connection; no mounting bracket; 90° inlet and outlet tubing connections
* (For Lubricator Pump Rates Less than 6 drops per minute and greater than 3 drops per minute)
