8.1 Goal
8.1.1 The goal of this chapter is to provide for suitable systems on board the ship to ensure that bunkering can be conducted without causing danger to persons, the environment or the ship.
(CR) Plans and data to be submitted
.1 General arrangement of the gas fuel bunkering system including location of the gas detectors, electrical equipment and lighting
.2 Detailed drawings of the bunkering station, manifolds, valves, couplings and control stations
.3 Gas fuel piping systems including details of piping and associated components, design pressures, temperatures and insulation where applicable
.4 Material specifications for manifolds, valves and associated components
.5 Weld procedures, stress relieving and non-destructive testing plans
.6 Ventilation system
.7 Fixed gas detection and alarm systems, and associated shut-off and shutdown systems
.8 Descriptions and schematic diagrams for control and monitoring system including set points for abnormal conditions
.9 Details of all electrical equipment in the bunkering and control stations
.10 Equipotential bonding and insulating flange arrangement
.11 Emergency shutdown (ESD) arrangements and ESD flow chart
.12 Operating and maintenance instruction manuals
.13 Testing procedures during sea/gas trials (submitted for survey verification only)
8.2 Functional Requirements
8.2.1 This chapter relates to functional requirements in 3.2.1 to 3.2.11 and 3.2.13 to 3.2.17 of the Guidelines. In particular the following apply:
8.2.1.1 The piping system for transfer of fuel to the storage tank shall be designed such that any leakage from the piping system cannot cause danger to personnel, the environment or the ship.
CR Classification Society (CR)
The purpose of this Chapter is to define the on-board requirements for fuel bunkering systems to enable safe and effective transfer of LNG or CNG from the bunker supplier (ship/truck/terminal) to the ship gas storage system.
It is understood that the on-board bunkering system would typically comprise a bunkering station located on either side of the ship. Each station would have provision for one bunkering line and one return line together with inert gas purging facility, associated relief/safety valves and control station. The LNG or CNG is led by piping from the bunker station to the gas storage tank(s). Consideration is to be given to relevant aspects of related standards such as ISO 28460, EN 1473, EN 1474, etc., and the ISO Technical Specification ISO/TS 18683 ‘Guidelines for systems and installations for supply of LNG as fuel to ships’.
8.3 Regulations for Bunkering Station
8.3.1 General
8.3.1.1 The bunkering station shall be located on open deck so that sufficient natural ventilation is provided.
Closed or semi-enclosed bunkering stations shall be subject to special consideration within the risk assessment.
IACS Interpretation of 8.3.1.1
The special consideration is to include, but not be restricted to, the following design fea tures:
Segregation towards other areas on the ship Hazardous area plans for the ship
Requirements for forced ventilation
Requirements for leakage detection (e.g., gas detection and low temperature detection) Safety actions related to leakage detection (e.g., gas detection and low temperature detection) Access to bunkering station from non-hazardous areas through airlocks
Monitoring of bunkering station by direct line of sight or by closed-circuit television(CCTV)
8.3.1.2 Connections and piping shall be so positioned and arranged that any damage to the fuel piping does not cause damage to the ship's fuel containment system resulting in an uncontrolled gas discharge.
8.3.1.3 Arrangements shall be made for safe management of any spilled fuel.
(CR)
Drip trays as per 5.10 of the Guidelines are to be provided beneath bunkering connections to protect the hull structure from low temperatures. Where the leakage containment arrangements are such that damage to the hull structure from accidental spillage of LNG during bunkering operations cannot be precluded, additional measures such as a low-pressure water curtain, are to be fitted under the bunkering station to provide fo r additional protection of the hull steel and the ship’s side structure.
8.3.1.4 Suitable means shall be provided to relieve the pressure and remove liquid contents from pump suctions and bunker lines. Liquid is to be discharged to the liquefied gas fuel tanks or other suitable location.
8.3.1.5 The surrounding hull or deck structures shall not be exposed to unacceptable cooling, in case of leakage of fuel.
8.3.1.6 For CNG bunkering stations, low temperature steel shielding shall be considered to determine if the escape of cold jets impinging on surrounding hull structure is possible.
8.3.2 Ships' fuel hoses
8.3.2.1 Liquid and vapour hoses used for fuel transfer shall be compatible with the fuel and suitable for the fuel temperature.
8.3.2.2 Hoses subject to tank pressure, or the discharge pressure of pumps or vapour compressors, shall be designed for a bursting pressure not less than five times the maximum pressure the hose can be subjected to during bunkering.
8.4 Regulations for Manifold
8.4.1 The bunkering manifold shall be designed to withstand the external loads during bunkering. The connections at the bunkering station shall be of dry-disconnect type equipped with additional safety dry break-away coupling/ self-sealing quick release. The couplings shall be of a standard type.
8.4.2 (CR)
Arrangements are to be provided for the installation of an emergency release system. These are to be designed to prevent damage and spark generation and to minimize release of LNG when activated. The release system is to incorporate suitable means to prevent accidental operation and is to be of the fail release type. It is recognized that these features may well be within the scope of the bunker supplier (bunkering ship, truck or shore side facility).
8.4.3 (CR)
Filters/strainers are to be fitted to prevent the transfer of foreign objects.
8.5 Regulations for Bunkering System
8.5.1 An arrangement for purging fuel bunkering lines with inert gas shall be provided.
8.5.2 The bunkering system shall be so arranged that no gas is discharged to the atmosphere during filling of storage tanks.
8.5.3 A manually operated stop valve and a remote operated shutdown valve in series, or a combined manually operated and remote valve shall be fitted in every bunkering line close to the connecting point. It shall be possible to operate the remote valve in the control location for bunkering operations and/or from another safe location.
(CR)
The remote operated valve is to be of the fail closed type (closed on loss of actuating power), be capable of local manual closure and have positive indication of the actual valve position.
8.5.4 Means shall be provided for draining any fuel from the bunkering pipes upon completion of operation.
8.5.5 Bunkering lines shall be arranged for inerting and gas freeing. When not engaged in bunkering, the bunkering pipes shall be free of gas, unless the consequences of not gas freeing is evaluated and approved.
8.5.6 In case bunkering lines are arranged with a cross-over it shall be ensured by suitable isolation arrangements that no fuel is transferred inadvertently to the ship side not in use for bunkering.
CR Classification Society
8.5.7 A ship-shore link (SSL) or an equivalent means for automatic and manual ESD communication to the bunkering source shall be fitted.
(CR)
An ESD system in accordance with 15.5.4 of the Guidelines is to be operational during bunker operations to enable a safe shut down in the event of an emergency during bunker delivery.
8.5.8 If not demonstrated to be required at a higher value due to pressure surge considerations a default time as calculated in accordance with 16.7.3.7 of the Guidelines from the trigger of the alarm to full closure of the remote operated valve required by 8.5.3 of the Guidelines shall be adjusted.
8.6 (CR) Gas Detection
Enclosed or semi-enclosed bunker stations and ducts around fuel gas bunker pipes are to be fitted with permanently installed gas detectors in accordance with 15.8 of the Guidelines.
Monitoring and safety system functions are to be provided in accordance with Table 15-3 of the Guidelines.