NFS No-Flow Safety Switch
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. Oil flow is through the switch -- forcing the plunger off its contact. Its rate of travel is controlled by fluid slippage past the precision-fit plunger, preventing premature shutdown. If the lubricator stops pumping, the plunger will drift to the contact and stop the engine. On start up, the first stroke of the lubricator automatically opens the switch. In operation the plunger can pump out of its hole on very high feed rates and does not obstruct flow. The time interval between lubrication failure and shutdown can be adjusted by increasing or decreasing the compression on the spring.
- 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
- Explosion-proof models available
- Overpressure rupture assembly optional
- Low flow-rate option available
- Switch contact rating – 2A at 30 VAC / DC
The switch is available with an overpressure rupture assembly which will instantaneously bleed off and stop the engine in the event that the lube-line check-valve plugs. The standard rupture disc fails at 1750 psi. Other rupture-pressure options available upon request.
The non-explosion proof switch has been tested to 5,000 psi. Its maximum recommended working pressure is 2,000 psi. The explosion-proof switch has been tested to 15,000 psi and its recommended working pressure is 8,600 psi.
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.
MATERIALS OF CONSTRUCTION:
MATERIALS OF CONSTRUCTION:
Body – Aluminum
Seal Material – Buna-N
Spring – Stainless Steel
STANDARD MODEL OPTIONS:(* For Lubricator Pump Rates of 6 Drops Per Minute or More)
NFS-3 = No-Flow Switch without Mounting Bracket
NFS-4 = No Flow Switch with Mounting Bracket for Ajax
NFS-5 = Triple No-Flow Switch with Mounting Bracket for Large Ajax (3 switches on one bracket)
NFS-6 = Explosion-Proof No-Flow Switch
NFS-7 = No-Flow Switch with Overpressure Rupture Assembly
NFS-9 = No-Flow Switch with Overpressure Rupture Assembly and Mounting Bracket for Ajax
NFS-25 = Explosion-Proof No-Flow Switch with Overpressure Rupture Assembly
LIGHT-SPRING MODEL OPTIONS:(* For Lubricator Pump Rates Less than 6 Drops Per Minute and Greater than 3 Drops Per Minute)
NFS-3L = No-Flow Switch without Mounting Bracket
NFS-4L = No Flow Switch with Mounting Bracket for Ajax
NFS-5L = Triple No-Flow Switch with Mounting Bracket for Large Ajax (3 switches on one bracket)
NFS-6L = Explosion-Proof No-Flow Switch
NFS-7L = No-Flow Switch with Overpressure Rupture Assembly
NFS-9L = No-Flow Switch with Overpressure Rupture Assembly and Mounting Bracket for Ajax
NFS-25L = Explosion-Proof No-Flow Switch with Overpressure Rupture Assembly