•
Exhaust gas pipes
•
Exposed parts of pipes with temperature > 60°C
Insulation is also recommended for:
•
Pipes between engine or system oil tank and lubricating oil separator
•
Pipes between engine and jacket water preheater
5.6
Local gauges
Local thermometers should be installed wherever a new temperature occurs, i.e. before and after heat ex-
changers, etc.
Pressure gauges should be installed on the suction and discharge side of each pump.
5.7
Cleaning procedures
Instructions shall be given at an early stage to manufacturers and fitters how different piping systems shall
be treated, cleaned and protected.
5.7.1 Cleanliness during pipe installation
All piping must be verified to be clean before lifting it onboard for installation. During the construction time
uncompleted piping systems shall be maintained clean. Open pipe ends should be temporarily closed.
Possible debris shall be removed with a suitable method. All tanks must be inspected and found clean
before filling up with fuel, oil or water.
Piping cleaning methods are summarised in table below:
Table 5.3 Pipe cleaning
Methods
System
A,B,C
D,F
1)
Fuel gas
A,B,C,D,F
Fuel oil
A,B,C,D,F
Lubricating oil
A,B,C
Starting air
A,B,C
Cooling water
A,B,C
Exhaust gas
A,B,C
Charge air
1)
In case of carbon steel pipes
Methods applied during prefabrication of pipe spools
A = Washing with alkaline solution in hot water at 80°C for degreasing (only if pipes have been greased)
B = Removal of rust and scale with steel brush (not required for seamless precision tubes)
D = Pickling (not required for seamless precision tubes)
Methods applied after installation onboard
C = Purging with compressed air
F = Flushing
5.7.2 Pickling
Prefabricated pipe spools are pickled before installation onboard.
Pipes are pickled in an acid solution of 10% hydrochloric acid and 10% formaline inhibitor for 4-5 hours,
rinsed with hot water and blown dry with compressed air.
After acid treatment the pipes are treated with a neutralizing solution of 10% caustic soda and 50 grams
of trisodiumphosphate per litre of water for 20 minutes at 40...50°C, rinsed with hot water and blown dry
with compressed air.
32
Product Guide Wärtsilä 34DF - 3/2012
Product Guide
5. Piping Design, Treatment and Installation
