Seal Chamber; Repairs; General; Changing The Impeller And Pump Unit - Homa CH407 Originalbetriebsanleitung

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. Repairs

7.1. General

The following repairs can be carried out on this machine:
•

Changing the impeller and pump unit

• Changing wear rings
When carrying out repair work, the following information
should always be noted:
• Round sealing rings as well as existing seals should
always be replaced.
• Screw fixings such as spring washers should always
be replaced.
• The correct torques must be observed.
In general, the following applies to repairs:
Switch off the machine, disconnect it from the mains
(have this done by an electrician), clean it and place
it on a solid base in a horizontal position. Secure it
from falling over and/or slipping.
If not otherwise stated, the torque values of the
below tables should be used. Values stated are for clean,
lubricated screws. Fixing torque [Nm] for screws A2/A4
(Coefficient of friction = 0,2)
A2/A4,
Hardeness class 70
DIN912/DIN933
M6 7 Nm
M8 17 Nm
M10 33 Nm
M12 57 Nm
M16 140 Nm
M20 273 Nm
7.2. Changing the impeller and pump unit
Changing the impeller and the pump unit.
• Loosen and remove the screws on the sealing
housing.
• 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 locking screw!
• Remove the impeller from the shaft using a suitable
extractor.
• Cleaning the shaft
• Attach a new impeller to the shaft.
Make sure that the sliding surfaces do not become
damaged!
• Screw a new impeller fastener (cylinder screw with
socket hex and a new screw fixing) back into the
shaft. Fasten the impeller and tighten the fastening
screw.
• Place the pump unit on the sealing housing and
fasten it with screws.
• It must be possible to turn the impeller by hand.
Changing wear ring
The stationary and mobile wear ring determine the gap
between the impeller (mobile wear ring) and the intake
port (stationary wear ring). If this gap is too big, the perfor-
mance of the machine decreases, and/or it can lead to en-
tanglements. Both rings are designed so that they can be
replaced. This minimizes wear on the intake port and and
impeller, consequently reducing expense for spare parts.
Changing sealing parts
Changing sealing parts on the liquid side such as the block
seal cartridge and the mechanical seal shaft requires a
certain amount of specialist knowledge about these sen-
sitive components. In addition to this, in order to carry out
the work, much of the machine must be dismantled. Only
original parts may be used for replacement! Inspecting
and replacing these parts is performed by the manufac-
turer during the general overhaul or by specially trained
personnel.
For machines approved for work in areas subject to
explosion danger, please refer to the "EX-protection"
in the appendix.
A2/A4,
Hardeness class 80
DIN912/DIN933
11,8 Nm
28,7 Nm
58 Nm
100 Nm
245 Nm
494 Nm
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