WÄRTSILÄ WARTSILA 20, Product Manual

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Standard Pressure class Size Pipe connections
ISO 7005-1 PN16 DN80 LT-water inlet 451
ISO 7005-1 PN16 DN80 LT-water outlet 452
DIN 2353 PN250 OD12 LT-water air vent from air cooler 454
ISO 7005-1 PN16 DN80 LT-water from stand-by pump 457
Plug - M18 x 1.5 LT-water drain 464
The fresh water cooling system is divided into a high temperature (HT) and a low temperature
(LT) circuit. The HT water circulates through cylinder jackets and cylinder heads.
The LT water circulates through the charge air cooler and the lubricating oil cooler, which is
built on the engine.
Temperature control valves regulate the temperature of the water out from the engine, by
circulating some water back to the cooling water pump inlet. The HT temperature control valve
is always mounted on the engine, while the LT temperature control valve can be either on the
engine or separate. In installations where the engines operate on MDF only it is possible to
install the LT temperature control valve in the external system and thus control the LT water
temperature before the engine.
9.2.1 Engine driven circulating pumps
The LT and HT cooling water pumps are engine driven. The engine driven pumps are located
at the free end of the engine.
Pump curves for engine driven pumps are shown in the diagrams. The nominal pressure and
capacity can be found in the chapter Technical data.
Fig 9-2 Pump curves
Table 9-1 Impeller diameters of engine driven HT & LT pumps
LT impeller [Ø mm] HT impeller [Ø mm] Engine speed [rpm] Engine
type
187
170 180
170 900
1000
W 4L20
187
175 187
175 900
1000
W 6L20
197
187 191
180 900
1000
W 8L20
197
187 191
180 900
1000
W 9L20
Wärtsilä 20 Product Guide - a13 - 6 September 2016 9-3
9. Cooling Water System Wärtsilä 20 Product Guide