Hi everybody,

I have to assess piping onboard a ship.

There are load cases to be adressed such as hogging, sagging, elongation and contraction of hull due to temperature, accelerations due to pitch and roll, ...

So far, accelerations I accounted for in piping stress analysis where classified as occasional (i.e. for static seismic equivalent).

I've tried to look into IGC code (Lloyd's or BV) but did not find any classification into operating or occasional stress types.

Can we consider acceleration as occasional even though it could happen every 10 seconds for the entire life of the ship (maybe 20 years)?

1) Can anyone help me find it in the books or give me advice concerning stress types for shipboard piping?

2) As far as I've seen, increase in stress is not so high; I've seen more increase in forces and moments on the equipment. Does it mean the stress classification is not the first concern?

yours ,