Hi , hoping someone has had this issue before.
We are replacing the overboard discharge butterfly valve for a fresh water generator in drydock , but the class surveyor is telling us that it has to be a non return valve as per load line regs. I think he is wrong.
The system was fitted from new building in the 90's but has been blanked off for the last five years. We are just putting it back as per the original ships drawings which show a butterfly valve at the O/B and must have been approved by Class.
The load line regs 22 states ;
Discharges led through the shell either from spaces below the freeboard deck or from within superstructures and deckhouses on the freeboard deck fitted with doors complying with the requirements of Regulation 12 shall be fitted with efficient and accessible means for preventing water from passing inboard. Normally each separate discharge shall have one automatic non-return valve with a positive means of closing it from a position above the freeboard deck.
I think the key here is the word "spaces" . This is not meant to apply to closed systems.
I think the regulations is meant to apply to system that are open at one end , like bilge systems, sanitary systems, scuppers.
I do remember having this argument many years ago in a small ship yard that was building a luxury yacht to survey, and I am sure that was the decision.
Has anyone else been down that road?