A.III Pipe and Duct Penetrations
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Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.754(18) – Recommendation on Fire Resistance Tests for “A”, “B” and “F” Class Divisions – (Adopted on 4 November 1993) - Annex - Recommendation on Fire Resistance Tests for “A”, “B” and “F” Class Divisions1 - Appendix - Testing of Windows, Fire Dampers, Pipe Penetrations and Cable Transits - A.III Pipe and Duct Penetrations

A.III Pipe and Duct Penetrations

Parent topic: Appendix - Testing of Windows, Fire Dampers, Pipe Penetrations and Cable Transits

1 General

 "A" class divisions may have to be provided with apertures to allow them to be penetrated by service pipes and ducts, and it is necessary to reinstate the insulation and/or integrity performance of the division at the position where it has been penetrated.

 Administrations may have different requirements relating to the need to classify pipe and/or duct penetrations, e.g. related to the pipes' diameter and their direct attachment or not to the structural core.

 This section refers from hereon to pipe penetrations but may be read as equally applicable to duct penetrations.

2 Nature of test specimens

2.1 Dimensions

 The maximum and minimum sizes (in terms of both the width and the height, or diameter) of each type of pipe penetration for which approval is sought should be tested in both vertical and horizontal orientation.

2.2 Design

  2.2.1 A bulkhead which includes the pipe penetration should be constructed in accordance with 2.1.1 of the recommendation and should be insulated to class A-60 on the stiffened face, which should be the face which is not exposed to the heating conditions of the test. A deck which includes the pipe penetration should be constructed in accordance with 2.2.1 of the recommendation and should be insulated to class A-60 on the stiffened face, which should be the face which is exposed to the heating conditions of the test.

  2.2.2 The pipe penetrations should be positioned only in the top half of a bulkhead but should not be closer than 200 mm from the edges of a bulkhead or a deck. Where more than one pipe penetration is to be tested simultaneously in a division, the separation between adjacent penetrations should not be less than 200 mm. Both measurements should relate to the distance to the nearest part of the penetration system, including any insulation which is part of the system.

  2.2.3 Each pipe passing through a penetration should project 500 ± 50 mm beyond the exposed end of the penetration and 500 ± 50 mm beyond the unexposed end of the penetration. The exposed end of the pipe should be blanked off, using an appropriate methodology to ensure that any fire penetration into the pipe does not occur via the end of the pipe in advance of it occurring through the exposed perimeter of the pipe.

  2.2.4 Each pipe should be firmly supported and fixed independent of the bulkhead or deck on the unexposed side of the test specimen, e.g. by a framework mounted from the restraint frame. The support and fixing of the pipe should restrain it from movement during the test.

3 Instrumentation

3.1 Positioning of thermocouples on the specimen

 For each pipe penetration, two thermocouples should be fixed on the unexposed face at each of the following locations:

  • on the surface of the pipe at a distance of 25 mm from the centre of the thermocouples to the position where the pipe emerges from the penetration seal;
  • on the pipe penetration at a distance of 25 mm from the centre of the thermocouples to the face of the insulation on the unexposed side of the test specimen; and
  • on the surface of any insulation or filling material used between the pipe and any coaming or spigot fixed to the division (provided that the gap between pipe or any such coaming or spigot is greater than 30 mm), or on the surface of any collar or shroud used between the pipe and the division (e.g. vapour barrier).

 For pipe penetrations in bulkheads, for each of the positions indicated above, one of the thermocouples should be fixed directly above the centre of the pipe and the other thermocouple should be fixed directly below the centre of the pipe.

 Additional thermocouples may be required to be fitted, dependent upon the complexity of the pipe penetration.

4 Performance criteria

4.1 General

 The performance of pipe penetrations may be related to their ability to satisfy both the insulation and the integrity criteria or may be related only to the requirements for integrity, depending on the requirements of the Administration.

4.2 Insulation

 Since the pipe penetration is a local weakness in the division it should be capable of preventing a temperature rise at any point on the surface not exceeding 180°C above the initial temperature. The average temperature rise is not relevant.

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