Section 9 Transfer of liquids
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Naval Ships, January 2023 - Volume 3 Additional Class Notations - Part 1 Ship Type Capability - Chapter 5 Replenishment at Sea (RAS) Systems - Section 9 Transfer of liquids

Section 9 Transfer of liquids

9.1 General

9.1.1 Systems for the transfer of liquids are to be designed to minimise to as low as reasonably practicable the risks inherent with the RAS operational requirements for dealing with large quantities of fluids at high transfer rates.

9.1.2 The design of liquid transfer systems is to be such that it minimises danger to the ship, personnel and the environment.

9.1.3 Liquid transfer systems are to be designed to prevent over-pressurisation of transfer and filling lines and all associated storage tanks, and any relief valve fitted for this purpose is to discharge to an overflow tank or other safe position. The design of filling systems is to consider maximum filling rates, dynamic pressure drops and maximum static pressures of the storage tanks.

9.1.4 The design and arrangements of liquid transfer systems is to permit clearing/drainage/effective drainage of transfer hoses after RAS operations have been completed.

9.1.5 The arrangements for abeam transfer of fuel oil, lubricating oils, aviation fuel and fresh water are to be such that in the event of a single failure in a transfer system, this does not prevent transfer of these liquids, e.g. more than one RAS connection on each side of the ship and the ability to fill any tank from each RAS station from designated connections is to be provided.

9.1.6 Any storage tank overflow arrangements are to discharge to a safe position.

9.1.7 For requirements relating to water storage systems, see Vol 2, Pt 11, Ch 1 Made and Fresh Water Systems.

9.1.8  For requirements relating to aviation fuel storage systems, see Vol 2, Pt 7, Ch 4 Aircraft/Helicopter/Vehicle Fuel Piping and Arrangements.

9.1.9 For requirements relating to fuel oil storage systems, see Vol 2, Pt 7, Ch 3 Machinery Piping Systems.

9.1.10 For requirements relating to air, overflow and sounding systems, see Vol 2, Pt 7, Ch 2, 10 Air, overflow and sounding pipes.

9.1.11 For requirements relating to piping system design, see Vol 2, Pt 7, Ch 1 Piping Design Requirements.

9.1.12 For requirements relating to electromagnetic hazards, see Vol 2, Pt 1, Ch 3, 4.18 Electromagnetic hazards.

9.1.13 For requirements relating to control of static electricity, see Vol 2, Pt 9, Ch 1, 2.4 Earthing and bonding .

9.2 Filling and supply connections and arrangements

9.2.1 Filling and supply connections for liquid RAS operations are to be sited within the boundary of the RAS station. Fuel oil system risers are to terminate in the vicinity of the RAS dump area and are not to present a tripping hazard or impede the use of stores handling machinery. Each filling and supply connection is to be provided with an accessible isolating valve located in close proximity to its associated. See also Vol 3, Pt 1, Ch 5, 9.2 Filling and supply connections and arrangements 9.2.14.

9.2.2 As far as practicable, separate filling and supply connections are to be provided for each type of fluid that may be transferred. To reduce the risk of inadvertent incorrect hose connection, the filling and supply connections are to be of different types and separated as far as possible from each other and distinct for for each type of liquid to be transferred.

9.2.3 A strainer unit, capable of being cleaned and a means of sampling incoming liquids, is to be provided at each filling connection.

9.2.4 Each filling and supply connection is to be provided with a permanently attached notice identifying the fluid storage system(s) connected to the filling and supply connection(s).

9.2.5 Filling and supply connections and associated isolating valves are to be made from ductile materials. Where ships are required to operate in cold weather environments, materials of toughness greater than grade E are to be used.

9.2.6 Filling and supply connections are to be designed to allow an emergency breakaway to take place safely, speedily and with a minimum effort from the crew.

9.2.7 Filling and supply arrangements for flammable/hazardous liquids are to be designed to minimise the risk of static electricity build-up. The piping arrangements within storage tanks are to have outlet ends configured to reduce turbulence and foaming of the fuel. See Vol 2, Pt 9, Ch 1, 2.4 Earthing and bonding for requirements for control of static electricity.

9.2.8 The control of filling and supply operations for each system that can be used during RAS operations is to be capable of being carried out from a designated Master Filling/Supply Control Station. Designated Master Filling/Supply Control Stations are to be provided with:

  1. Effective communication equipment that permits communication with locations identified in the engineering and safety justification.

  2. Indication of tank high level and overflow alarms.

  3. Tank level/content indication.

  4. A clear visual means of ascertaining the valve configuration of each filling/supply system.

9.2.9 The arrangements for replenishment of fuel oil and aviation fuel are to cater for water-compensated tanks where these tanks are installed. See Vol 2, Pt 7, Ch 3, 4.19 Water compensated fuel oil tanks.

9.2.10 The pipes for lubricating oil and fresh water transfer systems are to be permanent to minimise the risk of contamination.

9.2.11 Lubricating oil and fresh water transfer/ filling arrangements are to be provided with a bulkhead filling connection positioned not less than 300 mm above the weatherdeck to minimise the risk of sea-water ingress into the system.

9.2.12  The arrangements for transferring lubricating oils are to be such that they permit the use of oil renovation systems whilst RAS operations are being carried out.

9.2.13 Filling and supply connection arrangements are to be designed as far as possible to reduce the incidence of, or opportunity for dissimilar metal corrosion.

9.2.14 Where ship design and arrangements permit, a dedicated compartment may be provided in close proximity to the RAS station which can be accessed from both port and starboard sides in which the commodity connection points, isolation valves and hoses are housed. This reduces the likelihood of dissimilar metal corrosion, negates the requirement for below deck isolating valves, flush deck fittings and reduces the upper deck clutter (radar cross-section) associated with stowing the hoses on the weather deck.


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