Pump Solutions Group Neptune Solenoid-driven Diaphragm Metering Pump ARPZ-31_61_12 - Manual (Page 18)

17
Installation
■Anti-siphon check valve
This pump is provided with an anti-siphon check valve. Use this valve at the injection point unless there is a good rea-
son not to do so. Be absolutely sure to install it in the following cases.
• When the injection point is open to the atmosphere and liquid is to be injected at a position lower than the level of the
liquid in the tank (prevention of siphoning)
• When the liquid is to be injected inside the suction-side pipe of a volute pump, etc.
• When a chemical greatly exceeding the pump’s rated discharge volume is being fed (prevention of overfeed)
✽ Even with a rising pipe, overfeed may occur if the pipe is too long.
• Take care when handling an anti-siphon check valve which is made of PVDF since it is fragile in the face of impact.
(1) The anti-siphon check valve for the FEC/FFC type has an R1/2 external thread whereas the FTC type has R1/2 and
R3/8 external threads. Provide an Rc1/2 or Rc3/8 internal thread at the injection point that fits the anti-siphon check
valve.
Connecting
(2) Wind sealing tape around the external thread of the anti-siphon check valve, and screw the valve into the injection point.
✽ If it is hard to screw the valve in, grasp the nozzle grip using a tool such as pliers, and tighten the valve gently.
✽ When connecting the tube with the anti-siphon check valve already mounted on it to the main pipe, be absolutely
sure to hold the valve body and turn the nut. If the nut is turned without holding the body, the threaded part on the
nozzle may be damaged.
Main pipe
Injection point
(Rc1/2)
FEC/FFC (w/ PE tube)
Nozzle grip
Nut
FEC/FFC (w/ PE tube)
Nut
Nozzle grip
FTC (w/ FEP tube)
FTC (w/ FEP tube)
Main pipe
Injection point
(Rc1/2 or Rc3/8)
NOTE
If the end of the anti-siphon check valve is too
long, cut it off so that the end will be positioned at
the center of the main pipe where the chemical is
to be injected prior to use.
It is recommended that the tube be attached to
the main pipe through a valve to enable the anti-
siphon check valve to be replaced or cleaned, etc.
✽ Use a valve made of materials which will resist
any corrosion resulting from the chemical used.
Anti-siphon
check valve
Valve
Example: FEC/FFC
Example: FEC/FFC
07-22_PZ総合取説_E.indd 17 07-22_PZ総合取説_E.indd 17 2008/02/13 8:50:56 2008/02/13 8:50:56