PIPING ON ALUMINUM SHIP 1

[Adrian77]

Dear Friends,

I'm looking for information on design criterias for piping onboard a all aluminum ship.
What are the material requirements an for pipe on engine room and auxilary systems',
I didn't see specific requirements from Class Society.

Thanks,

 

[arto]

Did you look @ ABS?

http://www.eagle.org/absdownloads/listdetails.cfm?id=32

 

[Adrian77]

Yes, thanks for the link arto, in fact there is a rule there. After checking, it seems to be what I had expected, means must be provided for insulation between steel piping and aluminum ship's hull.
I suppose that pipe hangers would be rubber coated and valves attached to bulkheads would have rubber gasket and some insulation in the bolts (somewhere I've read that galvanised bolts are good solution).

I'm thinking on using plastic coated valves for sea chests, discharges and those attached to bulkheads and tanks.

Can somebody comfirm that this solution is the right one?

Regards,

 

[MikeHalloran]

Galvanized bolts have their uses, but any joint anywhere between steel and aluminum needs to be 'galvanically isolated', which is a whole different thing. It means that there must be dielectric bushings, sleeves and washers placed so that the steel and the aluminum are not in contact anywhere. Generic 'rubber' and 'insulation' is not a sufficient specification; you will need to pick particular materials from a limited set, and document your selections.

You need to find out which of the classification societies will be inspecting your boat, and learn chapter and verse of their specific set of rules for material selection and for documentation.



Mike Halloran
Pembroke Pines, FL, USA

 

[liviebudgie]

As most machinary vibrates and the hull is meant to sit still use lots of flexible bellows and gaskets. this will also give the galvanic insulation along with thermal and noise insulation.