Regulation on Standard Discharge Connection - Annex IV

General Requirements:

• This Regulation comes under MARPOL Annex IV, Chapter 3 - Equipment and control of discharge, Regulation 10.

• All ships subject to Annex IV, irrespective of their size and the presence of a sewage treatment plant or sewage holding tank, shall be provided with a pipeline and the relevant shore connection flange to discharge sewage to the port sewage treatment facility.

• Both lines shall be fitted with a standard discharge connection to enable pipes to reception facilities to be connected with the ship's discharge pipeline.

• For ships in dedicated trades, i.e. passenger ferries, alternatively the ships discharge pipelines may be fitted with a discharge connection that can be accepted by the Administration, such as quick connect couplings.

• The Standard discharge connection shall be under the following table:

Description	Dimension
Outside Diameter	210 mm
Inside Diameter	According to the Pipe Outer Diameter
Bolt Circle Diameter	170 mm
Slots in Flange	4 holes, 18 mm in diameter equidistantly placed on a bolt circle of above diameter, slotted to the flange periphery. The slot width is 18 mm
Flange Thickness	16 mm
Bolts and Nuts:  Quantity and Diameter.	4, each 16 mm diameter and of suitable length

• The flange is designed to accept pipes up to a maximum internal diameter of 100mm and shall be of steel or other equivalent material having a flat face.

• The flange together with a suitable gasket shall be suitable for a service pressure of 600kPa 

• For ships having a moulded depth of 5 meters and less, the inner diameter of the discharge connection maybe 38 millimetres.

Reference: IMO Publications & Documents - International Conventions - MARPOL - Annex IV