Section 4 Ship-side Valves and Overboard Discharges

401. Scuppers, inlets, overboard discharges and sanitary discharges

1. A sufficient number of scuppers, arranged to provide effective drainage, are to be fitted to all decks.

2. Scuppers on weather portions of decks and scuppers leading from superstructures or deckhouses not provided with closing appliances are usually to be led overboard.

3. Scuppers led through the deck or shell are to have strength equivalent to that of surrounding hull structure, and due regard is to be taken to the corrosion resistance of the piping material.

4. Scupper pipes are to be well stayed to prevent any vibrations. Sufficient possibility for extension of the pipes is to be provided when necessary.

5. Scuppers from spaces below the freeboard deck or spaces within closed superstructures may be led to bilges. Scuppers leading overboard from these spaces are to comply with the requirements

given for discharges.

6. Scuppers from exposed superstructure deck, led through the craft's sides in the spaces mentioned at

Par 5 and not having closeable valves, are to have strength as required in 402. 4.

7. Discharges led through the shell either from spaces below the freeboard deck or from spaces within superstructures and deckhouses on the freeboard deck, fitted with effective watertight doors, are to be provided with efficient means for preventing water from passing inboard. Normally, each sepa- rate discharge is to have one automatic check valve with positive means of closing it from a posi- tion above freeboard deck.

8. The vertical distance from the design waterline to the inboard end of the discharge pipe exceeds 0.01 , the discharge may have two automatic non-return valves without positive means of closing, provided that the inboard valve is always accessible for examination under service conditions. Where that vertical distance exceeds 0.02 , a single automatic non-return valve without positive means of closing may be accepted. The means for operating the positive action valve is to be readily accessible and provided with an indicator showing whether the valve is

9. open or closed.

Valves on scuppers from weathertight compartments included in the stability calculations are to be

10. Main and auxiliary sea inlets and discharges in connection with the operation of machinery may be controlled locally. Such controls are to be readily accessible and are to be provided with in- dicators showing whether the valves are open or closed. In unmanned machinery spaces, main and auxiliary sea inlets and discharges in connection with the operation of machinery are to be operable from the operating compartment.

402. Ship-side valves and fittings

1. All sea inlets and discharges are to have easily operable valves of an approved type connected to the side or bottom of the craft by a substantial flange connection or equivalent.

2. The choice of material combination, dimensions and corrosion protection charge valves connection to the sides and bottom of the craft, is to be due to damage of such fittings is avoided.

3. Exhaust outlets through the side of the craft are to be so arranged that engine is avoided.

of the sea inlet and dis- arranged so that flooding

ingress of water into the

4. The thickness and diameter of piping between hull plating and closeable or non-return valve are to be chosen so as to achieve equivalent strength as the surrounding hull structure. Due regard is to be taken to the corrosion resistance of the piping material.