YOKOGAWA TB830D, User Manual, Page: 66 / 85

<8. MAINTENANCE>
8-5
IM 12B01B30-02EN 1st Edition : Mar. 08, 2023-00
8.6 Inspection solenoid valve
The solenoid valve has moving parts and has a limited service life. Check and inspect the
operation of solenoid valve as shown below. If any error is found, replace it with a new one.
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How to Inspect solenoid valve
(1) Set converter maintenance mode to On.
(2) Turn On/Off solenoid valve (SVs) in the converter "solenoid valve/WIPER OPERATION"
menu to confirm the operation.
(3) To exit solenoid valve operation check, turn Off converter maintenance mode.
Solenoid valve to be inspected include the following: See Figure 2.1 or Table 2.3 for the position
of these solenoid valves.
• SV1 (Measure): sample inlet
• SV2 (Wash):
Cleaning water inlet
• SV3 (Zero): Zero water inlet
• SV4 (Drain): Detector drainage
These solenoid valves are required for the Automatic cleaning/Automatic zero calibration. Inspect
them about every six months.
Operate solenoid valves (SVs) to check that the fluid flows normally when the solenoid valve
is opened and that there is no leakage when the solenoid valve is closed. Solenoid valve must
be replaced if any error is found during the inspection. In principle, contact YOKOGAWA if the
replacement of the solenoid valve is required.
8.7 Replacing the Zero Turbidity Filter Element
The zero turbidity filter element should be replaced at regular intervals. Refer to Figure 2.1 to
Figure 2.3.
(1) Make sure that the
valve2 and the valveV3 are closed.
(2) Close the valve2 and stop supplying tap water.
(3) Turn and remove the filter case. Be careful not to allow internal water to run over.
(4) If the inside of the case is dirty, clean it with a brush or relevant tool.
(5) Replace the filter element with a new one.
(6) Reassemble the filter in reverse order. At this time, be sure to install the O-ring correctly to
prevent water leakage.
(7) Open the valve (V2) for tap water control, installed before the zero turbidity filter, and (SV3)
after the filter. Open the valve (V3) (when “-A3” is selected) installed after the zero turbidity
filter gradually to feed the tap water. Run the zero water and check for any water leakage.
(8) Loosen the knob of the air vent at the top of the zero-turbidity filter and bleed the air until tap
water leaks out. After venting, tighten the valve securely.
(9) Allow the water to flow for at least 20 minutes to wet the filter element.
(10) Close the zero water drain valve after the zero turbidity filter.
(11) This completes the replacement.
Note
• If the zero turbidity filter is not to be used for a prolonged time, remove, dry, and store the
filter element in a dry place.
• Pass enough water through the filter element to wet it. Otherwise, air bubbles may enter and
affect the zero calibration.