Operation; Sight Glasses; Standstill; Maintenance - Bitzer K033N Instructions De Service

6 Operation

The pressure equipment must be monitored and
checked at regular intervals by qualified and authorised
staff. This is required by national regulations and the
EN378-4. The inspection intervals depend on the mode
of operation and must be defined by the end user.

6.1 Sight glasses

All sight glasses are provided with grooves to facilitate
reading.
Fig. 21: Grooved sight glass, liquid level in the middle
Most of the sight glasses are also provided with a ball
that floats on the liquid refrigerant. If the sight glass is
completely covered with liquid, it is located at the very
top of the sight glass, without liquid it is located at the
very bottom.
The pressure equipment for hydrocarbons which is
marked with the identification letter P in the model des-
ignation are not equipped with balls.

6.2 Standstill

The refrigerant side of the system can be switched off
without preparation. On the coolant side, a low coolant
flow through the pipe works is required even at stand-
still. In the long run, standing water and oxygen will cor-
rode each material. Special caution is required for ag-
gressive coolants, e.g. brackish water, water containing
solids or prone to biofouling.
NOTICE
!
!
Risk of corrosion!
During standstill periods, the coolant side of the
pressure equipment must be protected against
corrosion! Clean and dry the pressure equip-
ment and pipe works before longer standstill
periods.
50

7 Maintenance

Apart from the regular tests, the refrigerant side of the
shell and tube condenser is maintenance-free.
The coolant side must be cleaned at regular intervals.
The cleaning intervals depend directly on the quality of
the coolant used. Possible contamination:
• Solids in the coolant that have settled: sand, algae or
silt.
• Elements previously dissolved in water may have
formed solid deposits e. g. limescale.
• If cooled with seawater, shells may have grown on
the inside of the pipes.

7.1 Cleaning the coolant side

WARNING
The system is under pressure!
Serious injuries are possible.
Wear safety goggles!
▶ Have an appropriate brush ready. The brush mater-
ial must be stable but must not damage the inner
pipe profile.
Length: at least as long as the pipe bundle,
K033.(B)(P) .. K373H(B)(P): Brush diameter: 12 mm,
part number 990 401 02
K573H(B)(P) .. K4803T(B)(P): Brush diameter:
16 mm part number 990 401 03
▶ Have new gaskets ready for the reversing covers.
▶ Switch off the refrigeration system.
▶ Wait until all system parts have reached room tem-
perature.
▶ Continue see chapter Draining the coolant, page
51.
▶ Remove both reversing covers.
▶ Check the pipe bundle visually.

7.2 Mechanical cleaning of the pipe bundle

▶ Brush the deposits off carefully, e.g. algae, silt.
▶ If necessary, use a cleaning agent.
NOTICE
!
!
Risk of corrosion!
Cleaning agent must not react with the pipe ma-
terial!
▶ Thoroughly rinse each pipe of the pipe bundle.
DB-200-6