Hydrotest requirement for offshore Piping ûDNV standard

[sree60]

Dear readers

We are building piping to DNV offshore standard DNV-OS-D-101 Chapter 2 section F wherein the hydrostatic test requirement for Piping is specified as below:

1) Hydrostatic test before assembly on board:

All class I & II pipes and integral fittings shall be subjected to hydrostatic test after completion of manufacturer but prior to insulation and coating.

2) Hydrostatic test after assembly on board:

This requirement is after assembly on board.

Can anyone explain why this testing requirement is specified two times?

the normal practice is after pipe spools are fabricated at shop it is subjected to visual and NDE inspection and after assembly on board they are subjected to hydrotest.

Thanking in advance

sree

 

[Satsystem]

I read it as when fabricated in the workshop you do your fabrication pressure tests. Then when connected on board you are testing the full installation assembly which means all joints connected on board. Which is the norm.