Seal Chamber; Repair Work; General; Replacing Various Parts Of The Pump - Homa TP 28 Original Instruction Manual

If water is still present in the operating fluid, a seal may be
defective. Please consult your manufacturer. When using
sealing chamber or leakage monitoring, in the event of a
defective seal, the display will light up again within the
next 4 weeks after the exchange.
Generally, the following applies when changing operat-
ing fluid: Turn off machine, allow it to cool, disconnect
from the power supply (to be carried out by a specialist!),
clean and place on a solid surface in a vertical position.
Warm or hot operating fluid may be under pressure.
The emergent operating fluid may cause burns. There-
fore, allow the machine to cool to ambient tempera-
ture first! Secure against tipping over and/or sliding!

6.4. Seal chamber

Since there is a large number of variants and versions of
these pumps, the exact location of the locking screws var-
ies depending on the pump part used.
• Carefully and slowly unscrew the sealing chamber's
filler screw.
Attention: The operating fluid may be under pressure!
• Unscrew drain screw. Drain the operating fluid and
collect in a suitable container. Clean the drain screw,
equip with a new seal ring and tighten again. To drain
fully, the machine must be tipped slightly to the side.
Ensure that the machine cannot tip over and/or slide
away!
• Place machine horizontally and fill with operating
fluid. Observe the prescribed operating fluid and fill
quantities.
• Clean the filler screw, equip with a new seal ring and
tighten again.

7. Repair work

7.1. General

The following repair work may be done on this machine:
• Change of impeller and pump chamber
In general, the following should always be heeded when
doing this work:
• O-ring seals and existing seals must always be re-
placed.
• Screw locking devices such as spring washers must
always be replaced.
• Torque values must be complied with.
The following general guidelines apply to repair
work: Switch the machine off, disconnect it from the
grid, clean it and lay it in a horizontal position on a
firm supporting surface. Secure it against falling over
and/or slipping away!
Unless stated otherwise, the torque values in the Tables
should be used. Values for clean, lubricated screws.
Tightening torque [Nm] for A2/A4 screws (friction coeffi-
cient = 0.2)
A2/A4,
strength 70
DIN912/DIN933
M6 7 Nm
M8 17 Nm
M10 33 Nm
M12 57 Nm
M16 140 Nm
M20 273 Nm

7.2 Replacing various parts of the pump

Change impeller and pump unit
• Loosen and remove the screws on the sealing hous-
ing.
• Secure and remove the pump housing from the seal-
ing housing with suitable equipment, e.g. hoisting
gear. Place on a secure base.
• Fasten the impeller with suitable equipment, loosen
and remove the impeller fastening (cylindrical screw
with socket hex).
Pay attention to the screw locking device!
• Remove the propeller from the shaft with a suitable
puller.
• Clean the shaft
• Attach new propeller to the shaft.
Ensure that the mating surfaces are not damaged!
• Insert a new propeller attachment (cylinder head
screw with a hexagon socket and a new screw lock-
ing device) into the shaft. Firmly fix the propeller and
tighten the cylinder screw.
A2/A4,
strength 80
DIN912/DIN933
11.8 Nm
28.7 Nm
58 Nm
100 Nm
245 Nm
494 Nm
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