WÄRTSILÄ Vasa R22, Instruction Manual

Page: 233 / 297

cylinder head cooling water spaces may be checked by opening
the lower large plugs on the sides of the cylinder heads. The
turbochargers can be checked through the covers of the water
space and the coolers by removing the water boxes of the inlet
water.
The deposits can be of the most various structure and consis-
tence. In principle, they can be removed mechanically and/or
chemically as described below. More detailed instructions for
cleaning of coolers are stated in chapter 18., section 18.5.
a) Mechanical cleaning
A great deal of the deposits consists of loose sludge and solid
particles which can be brushed and rinsed off with water.
On places where the accessibility is good, e.g. cylinder liners,
mechanical cleaning of considerably harder deposits is efficient.
In some cases it is advisable to combine chemical cleaning with
a subsequent mechanical cleaning as the deposits may have
dissolved during the chemical treatment without having come
loose.
b) Chemical cleaning
Narrow water spaces (e.g. cylinder heads, coolers) can be cleaned
chemically. At times, degreasing of the water spaces may be
necessary if the deposits seem to be greasy (see chapter 18.,
section 18.5.4).
Deposits consisting of primarily limestone can be easily re-
moved when treated with an acid solution. Contrarily, deposits
consisting of calcium sulphate and silicates may be hard to
remove chemically. The treatment may, however, have a certain
dissolving effect which enables the deposits to be brushed off if
there is only access.
On the market there are a lot of suitable agents on acid base
(supplied e.g. by the companies mentioned in chapter 02., section
02.3).
The cleaning agents should contain additives (inhibitors) to
prevent corrosion of the metal surfaces. Always follow the manu-
facturer’s instructions to obtain the best result.
After treatment, rinse carefully to remove cleaning agent re-
siduals. Brush the surfaces, if possible. Rinse again with water
and further with a sodium solution of 5 % to neutralize possible
acid residuals.
19.3 Water pump
19.3.1 Description
The water pump is a centrifugal pump and is driven by the gear
mechanism at the free end of the engine. The shaft is made of acid
resistant steel, the impeller (2) and the sealing ring (3) of bronze
and the remaining details of cast iron.
The shaft is mounted in two ball bearings (11) and (12), which
19 Cooling Water System 22-9601
19 - 4 VASA 22