Annex IV- Regulations for the Prevention of Pollution by Sewage from Ships

Chapter 3 - Equipment and control of discharge

Regulation 10 - Standard discharge connections

1 To enable pipes of reception facilities to be connected with the ship's discharge pipeline, both lines shall be fitted with a standard discharge connection in accordance with the following table:

Standard dimensions of flanges for discharge connections
Outside diameter 210 mm
Inner diameter According to pipe outside diameter
Bolt circle diameter 170 mm
Slots in flange 4 holes, 18 mm in diameter, equidistantly placed on a bolt circle of the above diameter, slotted to the flange periphery. The slot width to be 18 mm
Flange thickness 16 mm
Bolts and nuts: quantity and diameter 4, each of 16 mm in diameter and of suitable length
The flange is designed to accept pipes up to a maximum internal diameter of 100 mm and shall be of steel or other equivalent material having a flat face. This flange, together with a suitable gasket, shall be suitable for a service pressure of 600 kPa.

For ships having a moulded depth of 5 m and less, the inner diameter of the discharge connection may be 38 mm.

2 For ships in dedicated trades, i.e. passenger ferries, alternatively the ship's discharge pipeline may be fitted with a discharge connection which can be accepted by the Administration, such as quick-connection couplings.