Section 6 Instrumentation, control, alarm and monitoring systems
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules for LNG Ships and Barges Equipped with Regasification Systems, July 2022 - Chapter 1 Rules for LNG Ships and Barges Equipped with Regasification Systems - Section 6 Instrumentation, control, alarm and monitoring systems

Section 6 Instrumentation, control, alarm and monitoring systems

Parent topic: Chapter 1 Rules for LNG Ships and Barges Equipped with Regasification Systems

6.1 Functional objectives

6.1.1 The regasification system shall be provided with appropriate controls for safe operation of the system with adequate alerts and safeguards.

6.2 Performance requirements

6.2.1 Instrumentation, control, alarm and monitoring systems shall comply with the requirements of this Section and Pt 6, Ch 1 Control Engineering Systems of the Rules for Ships.

6.2.2 The system shall be provided with automatic and/or remote controls to ensure the system operates within its design parameters.

6.2.3 A system for monitoring and indicating alerts shall be provided.

6.2.4 The system shall be provided with safeguards which will operate to prevent a hazard occurring or to reduce an existing hazard to persons, machinery or the ship or the environment.

6.2.5 Locations at which the regasification system is controlled shall be provided with a means of communication with the gas-receiving terminal, see Ch 1, 6.4 Communications.

6.2.6 The regasification system shall be provided with control, monitoring, alert and safety systems that will maintain the system throughout all normal and reasonably foreseeable abnormal conditions.

6.2.7 The system shall be provided with the alarms and shutdowns as identified by the system manufacturer. In the absence of such guidance, the alarms and shutdowns indicated in these Rules may be used.

6.3 Control station

6.3.1 A control station for the regasification system and ship-to-ship operations shall be arranged within a non-hazardous area. Emergency procedures, as defined in Section 3 of these Rules, concerning regasification and ship-to-ship transfer operations shall be capable of being performed from this station.

6.4 Communications

6.4.1 At least two means of communication shall be provided between the control station and the receiving terminal; one of these systems shall be independent of the main electrical supply.

6.4.2 Internal communication cables shall comply with the applicable requirements of the Rules for Ships.

6.4.3 The cable installation shall provide adequate protection against mechanical damage and electromagnetic interference.

6.4.4 Components shall be located with appropriate segregation such that the risk of mechanical damage or electromagnetic interference resulting in the loss of both active and stand-by components is minimised. Duplicated communication links and equipment shall be routed to give as much physical separation as is practicable.

6.5 Equipment and systems – Alarms, shutdowns and safeguards

6.5.1 Suitable interlocks shall be provided to prevent start-up of the regasification system under conditions which could hazard the system or its equipment and components.

6.5.2 The manufacturer shall identify the required alarms, shutdowns and safeguards for all vaporisers; the minimum required shutdowns are indicated in Table 1.6.1 Alarms, shutdowns and safeguards for vaporisers.

Table 1.6.1 Alarms, shutdowns and safeguards for vaporisers

Item Alarm Note
Gas discharge temperature Very Low Automatic shutdown
Sea-water (and heating medium) supply pressure Very Low Automatic shutdown
Indication of supply gas pressure to burner (SCV type) Very Low Automatic shutdown
Flame failure (SCV type) Failure Automatic shutdown
Indication of sump water level (SCV type) Very Low Automatic shutdown
Combustion air pressure (SCV type) Low Automatic shutdown
High Automatic shutdown
Flue gas temperature (SCV type) High Automatic shutdown
Gas leak detected   ESD operation (programmed)

Note 1. SCV type means submerged combustion vaporiser type.

Note 2. Any additional alarms and shutdowns identified during the Risk Assessment required in Ch 1, 3 Risk based analysis of these Rules are also to be provided.

Note 3. The Table contains the minimum list of alarms and shutdowns for a regasification plant; additional alarms and shutdowns may be necessary as determined through risk-mitigating activities in response to a completed Risk Assessment as required by Ch 1, 3 Risk based analysis of these Rules.

Note 4. If certain alarms and shutdowns are not applicable for the regasification system, sufficient evidence shall be produced to support the claim and shall form part of the Risk Assessment required by Ch 1, 3 Risk based analysis of these Rules.

6.5.3 The manufacturer shall identify required alarms, shutdowns and safeguards for the suction drum; the minimum shutdowns required are indicated in Table 1.6.2 Alarms, shutdowns and safeguards for suction drums.

Table 1.6.2 Alarms, shutdowns and safeguards for suction drums

Item Alarm Note
Suction drum pressure Low Automatic shutdown
Suction drum level Very low Automatic shutdown
Suction drum level Very high Automatic shutdown

Note 1. Any additional alarms and shutdowns identified during the Risk Assessment required by Ch 1, 3 Risk based analysis of these Rules are also to be provided.

Note 2. The Table contains the minimum list of alarms and shutdowns for a regasification plant; additional alarms and shutdowns may be necessary as determined through risk-mitigating activities in response to a completed Risk Assessment as required by Ch 1, 3 Risk based analysis of these Rules.

Note 3. If certain alarms and shutdowns are not applicable for the regasification system, sufficient evidence shall be produced and is to form part of the Risk Assessment required by Ch 1, 3 Risk based analysis of these Rules.

6.5.4 The control and monitoring arrangements shall be appropriate to enable the system to be controlled within the design parameters specified by the manufacturer.

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