scope:

General

This class guideline gives requirements for cargo vapour recovery systems required to be fitted for class notation VCS(3) and VCS(L, X%) according to DNV GL rules for classification: Ships DNVGL-RU-SHIP Pt.6 Ch.4 Sec.11 Cargo operations, on the following working principles:

- re-absorption of cargo vapours in the liquid cargo itself

- liquefaction of cargo vapours

- other principles may be considered on a case-by-case basis.

For systems where volatile organic compounds (VOC) shall be used as gas fuel for combustion machinery, DNVGL-RU-SHIP Pt.6 Ch.2 Sec.5 Gas fuelled ship installations, shall be taken into account to any part of the system interfacing with such a gas fuel system. Note that the use of VOC as fuel on board ships normally also require flag administration approval.

The requirements for this class notation are additional to the requirements for main class, given in DNVGLRU- SHIP Pt.1 to DNVGL-RU-SHIP Pt.4. App.A Table 1 shows some applicable rule references.

Refrigeration systems shall comply with the requirements given in DNVGL-RU-SHIP Pt.4 Ch.6 Piping systems. Where the refrigerant is a flammable medium, the refrigeration system shall comply with the requirements given in DNVGL-RU-SHIP Pt.5 Ch.7 Liquefied gas tankers.

The requirements shall apply to any vapour recovery system when installed onboard vessels classed with the Society.