Flexible Pipe Connections - Wartsila 31 Product Manual

Wärtsilä 31 Product Guide
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.
Great cleanliness shall be approved in all work phases after completed pickling.
5.8

Flexible pipe connections

Pressurized flexible connections carrying flammable fluids or compressed air have to be type
approved.
Great care must be taken to ensure proper installation of flexible pipe connections between
resiliently mounted engines and ship's piping.
● Flexible pipe connections must not be twisted
● Installation length of flexible pipe connections must be correct
● Minimum bending radius must be respected
● Piping must be concentrically aligned
● When specified the flow direction must be observed
● Mating flanges shall be clean from rust, burrs and anticorrosion coatings
● Bolts are to be tightened crosswise in several stages
● Flexible elements must not be painted
● Rubber bellows must be kept clean from oil and fuel
● The piping must be rigidly supported close to the flexible piping connections.
Wärtsilä 31 Product Guide - a1 - 18 October 2016
5. Piping Design, Treatment and Installation
5-5