Maintenance And Cleaning; Periodic Checks; Greasing The Bearings; Shaft Seal - DAB KDN 32-125.1 Anleitungen Für Installation Und Wartung

11.2. DANGER OF FROST: When the pump remains inactive for a long time at temperatures of less than 0°C, the pump body must
be completely emptied through the drain cap (26), to prevent possible cracking of the hydraulic components.
Check that the leakage of liquid does not damage persons or things, especially in plants that use hot water.
Do not close the drainage cap until the pump is to be used again.
When restarting after long periods of inactivity it is necessary to repeat the operations described above in the paragraphs
"WARNINGS" and "STARTING UP".
11.3. To avoid needless motor overloads, accurately check that the density of the pumped liquid corresponds to that used in the design
phase: remember that the power absorbed by the pump increases in proportion to the density of the liquid carried.
12.

MAINTENANCE AND CLEANING

The electropump can only be dismantled by competent skilled personnel, in possession of the qualifications
required by the legislation in force. In any case, all repair and maintenance jobs must be carried out only
after having disconnected the pump from the power mains. Ensure that it cannot be switched on accidentally.
If the liquid has to be drained to carry out maintenance, ensure that the liquid coming out cannot harm
persons or things, especially in systems using hot water.
The legal requirements on the disposal of any harmful fluids must also be complied with.
After a long period of operation there may be difficulties in removing the parts in contact with water: to do
this, use a special solvent available on the market and, where possible, use a suitable extractor.
Do not force the parts with unsuitable tools.
12.1.

Periodic checks

In normal operation, the pump does not require any kind of maintenance. However, from time to time it is advisable to check
current absorption, the manometric head with the aperture closed and the maximum flow rate, which will enable you to have
advance warning of any faults or wear. If possible, arrange for programmed maintenance so that problem-free operation may be
ensured with minimum expense and reduced machine down times, thus avoiding long and costly repairs.
12.2.

Greasing the bearings

Carry out maintenance based on the type of bearing indicated on the technical data plate.
see tables on page 120-121-122 (12.2.1 / 12.2.2 / 12.2.3 / 12.2.4)
12.3.

Shaft seal

The seal on the shaft may be a mechanical seal or a stuffing box seal.
12.3.1.

Mechanical seal

Normally no checking is required. Just ensure that there are no leaks of any kind. If leaks are present, change the seal as
described in par.12.4.2.
12.3.2.

Stuffing box seal.

Before starting, check that the follower nuts are resting on the follower so that there will be abundant leaks after the pump has
been filled. The follower must always be perfectly parallel to the surfaces of the cover that holds the seal (use a thickness gauge
to check this).
Switch on the power and start the pump. After it has been running for about 5 minutes, the leaks must be reduced, tightening
the nuts on the follower by about 1/6 of a turn. Check the leaks again after another 5 minutes. If the leaks are still excessive,
the operation must be repeated until the leaks reach a minimum value of 10 to 20 cm³/min.
If the leaks are too small, slightly slacken the nuts on the follower. If there is no leak at all, the pump must be stopped
immediately; slacken the nuts on the follower and repeat the starting operations described above in this paragraph.
After the follower has been regulated, observe the leaks for about 2 hours, at the maximum temperature of the pumped fluid
(MAX. 140°C) and at minimum working pressure, so as to ensure that the leaks are still efficient.
If operating below head with a pressure of >0.5 Bar at intake, the hydraulic ring (part 141 on the parts diagram) is no
longer necessary, in place of which another packing ring must be provided.
ATTENTION: If the leaks are not reduced when the follower nuts are tightened, the seals must be replaced as indicated in
par.12.4.3.
12.4.

Changing the seal

12.4.1.

Preparing disassembly

1. Switch off the electric power supply and ensure that it cannot be switched on accidentally.
2. Close the interception devices on intake and delivery.
3. If hot liquids have been pumped, wait until the pump body returns to room temperature.
4. Empty the pump body by means of the drainage caps, taking particular care if harmful fluids have been pumped (observe
the legal requirements in force).
5. Dismantle any auxiliary connections provided.
ENGLISH
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