030419.04
5
Waterlock NLP
ENGLISH
2.4 Hose connections
NLP40/45/50
NLP50S/60/75/90
In order to achieve the ideal connection between the hoses and the
waterlock, both hose connections turn through 360 degrees.
Loosen the bolts before turning the hose connections!
Tighten the hose connections to a torque of
1 Nm (0.75 ft.lb)
.
The top portion of the waterlock can be turned in a 360˚ radius.
The top portion should be turned as follows:
1 Unscrew the clamping strip
2 Turn the top portion to the desired position
3 Tighten the clamping strip sufficiently, to a torque of
0.3 Nm
(0.22 ft.lb)
.
2.5 Fitting the hose
To ease the fitting of the hose to the hose connector, use only water
and/or soap, NOT grease or products containing oil.
Fit each hose connection with 2 stainless steel 12 mm (0.5”) wide
hose clamps.
2.6 Sensor for temperature alarm
A sensor for a temperature alarm can be fitted in the exhaust pipe.
3
Installation Examples
Exhaust systems with a waterlock type NLP, silencer type MP, goose
neck type NLPG and a transom connection are shown on page 15.
Entry of water from the aft is almost completely prevented by the
extra height difference in the goose neck.
When the engine is stopped, any water which is still in the exhaust
pipe (between the highest point in the exhaust system and the ex-
haust silencer) will run back to the exhaust silencer.
To reduce the amount of this water as much as possible, the goose
neck should be fitted directly above the exhaust silencer, if possible
(see drawings 1 and 3).
When the goose neck is fitted directly to the transom (drawings 2
and 4), the maximum length of the exhaust pipe, between exhaust
silencer and the highest point, should be taken into account.
4
Prevention of syphoning
(drawings 3 & 4)
If the water injection point ‘C’ is below, or less than 15 cm (0.6”) above
the waterline (also when the ship heels under sail), there is a risk that
when the engine is stopped, the coolant water will enter the engine
due to syphoning. This syphoning can be prevented in two ways:
By creating an air vent system in the coolant water hose between
engine block and water injection point ‘C’, by fitting an air vent
with air vent pipe, for example.
The air vent pipe can be connected to its own hull outlet (H) or
to the connection on the gooseneck intended for this, type NLPG
(G). See the manual for the NLPG, no. 030428.0x.
By fitting an air vent (with valve) in the coolant water hose be-
tween the engine block and water injection point ‘C’.
5
Maintenance
Check all hose connections for gas and water leaks regularly.
Before the winter lay-up, drain the waterlock. The waterlock has two
drain plugs for this purpose.
