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8.0 - TROUBLE-SHOOTING COMMON TO DLX - DLXB SERIES PUMPS
8.1 - MECHANICAL FAULTS
As the system is quite robust there are no apparent mechanical problems. Occasionally there might be a loss of
liquid from the nipple because the tube nut has loosened, or more simply the discharge tubing-has broken.
Very rarely there may be losses caused by the breakage of the membrane, or by the membrane seals in which
case they have to be replaced by disassembling the four screws of the pump head fig. 12), when re-mounting
the pump head ensure that the screws are replaced properly, along with “O” ring.
After repair, the metering pump will need to be cleaned of additive residues which can damage the pump cas-
ing.
❶
- THE METERING PUMP GIVES PULSES BUT THE ADDITIVE IS NOT INJECTED
a.
Dismount the suction and discharge valves, clean them and replace, see position (fig. 12). Should the valves
be swollen, check valves material against our chemical resistance compatibility chart and fit correct valves.
Standard valves are Viton. Upon request Silicon, EPDM (Dutral), Nitryl and valves, ball check valve, K valve
can be supplied.
b. Check clogging of the filter.
ATTENTION: When removing the metering pump from the plant, be careful as there might be some residual
additive in the discharge hose.
8.2 - ELECTRICAL FAULTS
❶
ALL LEDS OFF, THE PUMP DOES NOT PULSE
Check power supply (socket, plug, power switch ON ), if the pump doesn’t work contact manufacturer Customer
Service, Dealer or Distributor.
❷
GREEN LED (POWER) ON, RED LED (PULSE) OFF, THE PUMP DOES NOT PULSE
Press the START button. If the pump doesn't work contact manufacturer Customer Service, Dealer or Distributor
❸
PUMP PULSES ARE NOT CONSTANT
Check that supply voltage is /- 10% of rated voltage.
❹
THE DOSING PUMP GIVES ONLY ONE PULSE
Disconnect the equipment and contact manufacturer Customer Service, Dealer or Distributor.
9.0 - ELECTRODE HOLDERS
Three different types of electrode holders are available: monotubular for immersion, electrode cell, and in-line.
It is essential to bear in mind that the distance between the injection point and the electrode must never be less
than one metre. When this is not possible, an appropriate chemical mixer must be inserted between the injec-
tion point and the electrode.
10.0 - ELECTRODE CLEANING AND MAINTENANCE
The formation of deposits on the electrode will produce erroneous readings. The necessary cleaning action
depends on the type of deposit under consideration. In the case of thin deposits, shake the electrode in the man-
ner of a thermometer or use a spray of distilled water. Organic residues or particularly resistant deposits should
be removed by chemical means. Mechanical cleaning of the bulb should be resorted to only in extreme cases,
but bear in mind that abrasion can lead to irreparable damage. If cleaning does not fully re-establish the effica-
cy of the electrode, it may be that the electrode has aged. Ageing will show itself in the for of either a measure-
ment error or a slow response.
