Section 9 Inspection and testing on completion
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Ships, July 2022 - Part 7 Other Ship Types and Systems - Chapter 1 Controlled Atmosphere Systems - Section 9 Inspection and testing on completion

Section 9 Inspection and testing on completion

Parent topic: Chapter 1 Controlled Atmosphere Systems

9.1 General

9.1.1 CA system trials are to be witnessed on board by the LR Surveyor, before the system is put into service and before a certificate is issued. These trials are in addition to any tests which may have been carried out at the manufacturer's works.

9.1.2 An Operating and Safety Manual for the guidance of the ship's staff is to be provided, covering the following topics:

  1. Principal information on the use of CA.

  2. Complete description of the CA installation on board.

  3. Hazards of low oxygen atmospheres and consequential effects on human life.

  4. Countermeasures when exposed to low oxygen atmospheres.

  5. Instructions for operation, maintenance and calibration of all gas detectors.

  6. Instructions for use of portable oxygen analysers with alarm for personal protection.

  7. Prohibition of entry to spaces under CA.

  8. Loading instructions prior to injection of gas.

  9. Procedure for checking security of CA zones, doors and access hatches prior to injection of gas.

  10. Gas freeing procedure for all CA zones.

  11. Procedure for checking atmosphere of CA zones before entry.

9.2 Gas supply and sampling systems

9.2.1 The gas supply main and branches are to be pressure and leak tested. The test pressures are to be 1,5 and 1,0 times the design pressure respectively.

9.2.2 All gas sampling lines are to be leak tested using a vacuum or overpressure method.

9.3 Air-tightness of CA zones

9.3.1 Air-tightness of each CA zone is to be tested and the results entered on the certificate. The measured leakage rate of each zone is to be compared with the specified value.

9.3.2 Either a constant pressure method or a pressure decay method is to be used to determine the degree of air-tightness.

9.3.3 If the constant pressure method is used, the test is to be carried out at the design pressure of the CA zones.

9.3.4 If the pressure decay method is used, the time for the pressure to drop from 350 Pa to 150 Pa is to be measured and the leakage is to be calculated using the following formula:

where
A.L. = air leakage, in m3/h
V = volume of zone, in m3
t = time, in seconds
7,095 = constant for 200 Pa pressure decay.

During this test, adjacent zones are to be kept at atmospheric pressure.

9.4 Gas system performance

9.4.1 Capability of the gas system to supply the gas at the specified flow rate and condition is to be verified by tests.

9.4.2 If the notation conditions cannot be verified during testing, assignment of the notation is to be deferred until log book entries confirm the achievement of the specified conditions in every CA zone during a loaded passage.

9.5 Gas freeing

9.5.1 The gas freeing arrangements are to be tested to demonstrate that they are effective.

9.6 Safety, alarms and instrumentation

9.6.1 The control, alarm and safety systems are to be tested to demonstrate overall satisfactory performance of the control engineering installation. Testing is also to take account of the electrical power supply arrangements, see also Pt 6, Ch 1, 2.3 Alarm systems, general requirements.

9.6.2 Locking arrangements of all CA zones and adjacent spaces where gas may accumulate, provision of warning notices at all entrances to such spaces, communication arrangements and operation of alarms, controls, etc. are to be examined.

9.6.3 The provision of portable gas detectors and personnel oxygen monitors are to be verified by the LR Surveyor. Suitable calibrated instruments for measuring the levels of O2, CO2 and humidity, gas pressure and gas flow to the CA zones, are to be provided for testing. Their accuracy is to be verified.

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