No valve closure delay means no water hammer and no noise
No-Feed Detector
For the safest automatic pumping, the No-Feed Detector is recommended.
The YOKOTA No-Feed Detector is a safety device to prevent the pump from
dry operation. Reacting to the movement of the check valve, the switch
cuts off power automatically when the amount of flow is close to zero.
If your pump is equipped with the Non-Water Hammer Check Valve with the
No-Feed Detector, there is no need to worry about the occurrence of water
hammer even if a high pressure tank is installed near the pump. Your automatic
pumping system will operate safely and reliably.
NP model
BP model
NP model (For SL-SN, SH)
Part name
Part name
41-1
Proximity switch
30-1
O-ring
41-2
Proximity member
31-1
O-ring
41-3
Case
31-2
O-ring
41-4
Support ring
1
Valve case
41-5
Cap
13
Valve arm pin
41-6
Set screw
19
Pin holder
41-7
Extension shaft
Use a flow speed of 0.38m/sec as a guideline for minimum flow rate setting.
However, use 120L/min as a minimum value for SNP-50, and 180L/min as a
minimum value for SNP-65, 80.
When not operating for long periods of time during winter, remove the cap
(41-5) and drain the water in the cap (or take measures to prevent the
No-Feed Detector from freezing.)
BP model (For SL-NB)
Part name
Part name
41-1
Case
41-80
Proximity switch
41-2
Cover
41-90
Set screw
41-3
Adjusting nut
41-10
Stopper
41-4
Coil spring retainer
41-11
Retainer
41-5
Proximity tip
31-20
Sheet packing
41-6
Cap
31-30
O-ring
41-7
Coil spring
2
Top cover
Use a flow speed of 0.38m/sec as a guideline for minimum flow rate setting.
However, use 100L/min as a minimum value for NBP-40.
Contact protector relay
The contact protector relay protects small capacity contacts of the proximity
switch. Please install the contact protector relay, using the specifications
below, in the control panel for the YOKOTA No-Feed Detector.
Connection and operation
Power supply
AC 100V, 200V
Control capacity
AC 10A-250V
DC 5A-30V
Feed condition
No-feed condition
Proximity switch
ON
OFF
Contact protector relay
a contact
b contact
a contact
b contact
ON
OFF
OFF
ON
Outline drawing
Wiring diagram
If voltage is applied to an incorrect connection (parts T, H, and S), the
proximity switch will be damaged.
Specifications stated here may be subject to change without notice due
to product improvement.
