IACS History File + TB Part A

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UR P3 “Air Pipe Closing Devices” Part A. Revision History Version no. Approval date Implementation date

when applicable Rev.3 (Nov 2012) 02 November 2012 1 January 2014 Rev.2 (March 2004) 04 March 2004 - Corr.1 (April 2002) 30 April 2002 - Rev.1 (May 2001) 17 May 2001 - Corr.1 (May 1998) 20 May 1998 - New (1991) No records - • Rev.3 (Nov 2012) .1 Origin of Change:

Suggestion by an IACS member .2 Main Reason for Change: To clarify the type-test method of P3 for tightness test and to evaluate tests to prove the ability to handle vacuum and criteria for the relationship area requirement and flow characteristics. .3 List of non-IACS Member classification societies contributing through the TC Forum and/or participating in IACS Working Group: None .4 History of Decisions Made: Form A was agreed in May 2011. .5 Other Resolutions Changes None .6 Dates:

Original Proposal: 10 March 2011 Made by a Member Panel Approval: 24 September 2012 GPG Approval: 02 November 2012 (Ref: 11068_IGd)

• Rev.2 (March 2004)

The review by AHG/FDG of BEA/mer technical report on air vent arrangements recommended amending the UR P3. All recommendations arising from AHG/FDF review were accepted by the WP and introduced into the draft revision.

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Original Proposal was made on 12 February 2004 and GPG Approval was given on 04 March 2004 (GPG subject No: 3003cIGb). See separate TB document in Part B Annex 2. • Corr.1 (April 2002) A member suggested editorial refinements to the UR P3 on 29 April 2002 and done on 30 April 2002. No TB document available. • Rev.1 (May 2001) AHG/PPV submitted proposed revision replacing the existing P3 to GPG 50 (0077a, 18/1/2001). Review of UR P1.2, P2.1, P2.2, P2.3, P2.5, and P3 has been carried out in line with annual Task 1A. The main goal of this review was elimination of IACS member reservation. As has been noted that: “P1 & P2 have not been implemented since the Rules are formatted around US standards such as ANSI, ASME, USC Regulations, etc. P 1 & P2 are not conductive (sic) to incorporate in the Rules”. With regard to P3, it needed to be changed editorially. Members unanimously agreed to the revision. See separate TB document in Part B Annex 1. • Corr.1 (May 1998) P.3.2.1 contained editorial error i.e. inclination of ±40 deg. C, which should read ±40 degrees. The error was corrected No TB document available. • NEW (1991) History files and TB documents are not available.

Part B

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Part B. Technical Background List of Technical Background (TB) documents for UR P3: Annex 1. TB for Rev.1 (May 2001)

See separate TB document in Annex 1.

◄▼► Annex 2. TB for Rev.2 (March 2004)

See separate TB document in Annex 2.

◄▼► Annex 3. TB for Rev.3 (Nov 2012)

See separate TB document in Annex 3.

◄▲► Note: There are no separate Technical Background (TB) documents for the original resolution (1991), Corr.1 (May 1998) and Corr.1 (April 2002).

TB submitted on 6 Feb 2001 by AHG/PPV Chairman P 3 (Rev.1)

Technical Background Documents

1. Review of UR P1 – P3 • Objective and Scope Review of UR P1.2, P2.1, P2.2, P2.3, P2.5, and P3 has been carried out in line with annual Task 1A. The main goal of this review was elimination of a Member’s reservation. As has been noted by the Member: “P1 & P2 have not been implemented since the Rules are formatted around US standards such as ANSI, ASME, USC Regulations, etc. P 1 & P2 are not conductive (sic) to incorporate in the Rules”. With regard to P3, it needed to be changed editorially. Member’s additional comments relative to the UR P: P 1.2.7: • Do not regard 14 bar as design pressure, otherwise, strainers, filters, heaters will have to be designed for 14 bar which may not be practicable. Also the testing pressure for these components will need to 1.5 the design pressure which may be a contentious issue. Accordingly the Member proposed that the 14 bar pressure should be considered as a special safeguard for the joints (see MSC Circ 647 & 851). • Working Group needed to discuss and determine whether the 14 bar pressure was applicable to valves also. Further, the Member has been informed by their office in the Pacific that pressure rating of JIS f 7399-1989 “Marine Fuel oil Tank Emergency Shut-off valves”, commonly used in that region, states that “Maximum working pressure shall be 0.098 MPa [ 1kg/cm2 ], although hydraulic inspection for body will be 0.686 MPa. Accordingly, it would not be possible to apply the 14 bar pressure to the suction side of the pump. P 2.2 Table (1): • There was a need to define what constitutes “special safeguard”. A Member’s observation of other Member societies Rules indicated that there were no provisions made for application of this in the design, construction or operational matters. • Member requested the WG to develop a list of provisions which may be considered “special safeguards” for various systems conveying flammable, toxic or corrosive media. • The reference to toxic and corrosive fluids may be out of place, as such systems were invariably cargo systems, which were outside the scope of P2. Accordingly considerations should be given to deleting this. • Source of Proposed Requirements A Member’s proposals on correction the UR P1, P2 and P3 circulated by e- mail dated 13 September 2000 has been used as a basis document for revision. • Points of discussion Unanimous agreement has been achieved.

Technical Background document for the revision of UR P3

1. Scope and Objective

The review by AHG/FDF of BEA/mer technical report on air vent arrangementsrecommended to amend the UR P3.

2. Points of discussion

All recommendations arising from AHG/FDF review were accepted by the WP andintroduced into the draft revision.

3. Source/derivation of proposed amendments

AHG/FDF Report to GPG as attached.

4. Decision

The draft was agreed by consensus. No Member requested any issue to be reflectedin the TB.

KP 12/02/04

5. GPG

Approved by GPG 4 March 2004, 3003cIGb, as submitted.

IACS AHG/FDFReport dated 27th May 2002 to IACS on:

Task 03: Review of the BEA/mer technical report on air vent arrangements

1. IACS Directive

Following discussion on the FRAMO system installed on the IEVOLI SUN,GPG decided to task AHG/FDF to review the recommendations contained inthe BEA/mer technical report on air vent arrangements and advise GPG.(0233_Igc, 29 August 2001). No Form A.

2. The BEA/mer Recommendations

A free translation of the recommendations contained within the BEA/merreport "Technical note on vent arrangements in ballast tanks and otherspaces", dated 7 may 2001 is as follows.

• IACS and classification societies should circulate a technical note aboutthe problems identified on automatic vent arrangements, installationprecautions, frequency of inspections, maintenance and replacement ofelements subject to deterioration.

• Include the inspection of vent arrangements in the technical specificationof the shipowner for repair works during ship stops.

• Frequency of inspections.Follow instructions assigned by manufacturers (it is recommended tomake an inspection every two years and a complete replacement of thevent arrangement between 8 to 10 years).

• For new ships, take into account a better protection of the ventarrangements against green seas at the time of their installation on board.

• Improve the means of protection against corrosion (treatment, coating)and ensure proper preparation of sampling.

• Improve the seal between the vent arrangement and seat (appropriatefloating ball / joint coupling) and smooth the seating arrangements of theball.

• Improve the design to facilitate inspection and maintenance of the partsmostly exposed to corrosion (the connecting pipe inside of the casing andthe air vent pipe, which should be as short as possible).

It seems that some manufacturers have already taken into account somemodifications.

3. Review of the BEA/mer recommendations

The seven recommendations listed above have been considered byAHG/FDF and are commented as below:

i) The first recommendation calls for IACS to circulate a technical notedescribing problems identified with automatic air pipe heads, installation,inspection and maintenance. Members of AHG/FDF reported that many

types of problems had been found on survey, but that the most prevalentwere those due to corrosion and/or lack of maintenance. Air pipe headsconstructed from galvanised steel were considered to be more prone toproblems caused by corrosion. It was therefore concluded that the mosteffective approach to combat these problems was through a defined surveyregime. A draft UR Z[ ] for automatic air pipe heads is in development.

ii) Include the inspection of vent arrangements in the technical specification ofthe ship owner for repair works during ship stops.This is interpreted to refer to the owners/managers repair specification fordocking/dry docking. Deficiencies should be identified and reported, ISMparagraph 5.1.5 refers.

iii) Frequency of inspections.AHG/FDF agreed that annual external inspections should continue as atpresent. In addition the draft UR Z[ ] is proposing requirements for thedismantling and survey of air pipe heads at each Special (Renewal) Survey.This is to provide for the internal inspection of air pipe heads, which for sometypes requires its removal from the air pipe.

iv) Better protection against green seas.Members considered those proposals for strength requirements under Task01 if extended to the remainder of the ship length could address this item.

v) Improve the means of protection against corrosion.The meaning of ‘ensure proper preparation for sampling’ is not clear, but isinterpreted as a reference to the quality control for the corrosion protection(e.g. galvanising).

As for the mechanism that may have caused the particular type of corrosionfound in the air pipe head from the Ievoli Sun, AHG/FDF postulated thefollowing.

During the ballasting of tanks, it is common practice to press the tanks up byfilling until water is flowing through the air pipe heads onto the deck. Thismeans that quite a high velocity of water is impacting on the lower part of theinner chamber for some types of head. As ballast is usually taken on in fairlyshallow water it is quite likely to contain some sediment. The action of watercontaining particles of sand, earth, etc will then tend to erode the zinc coatingparticularly over the area where the flow up the pipe is diverted around theouter chamber. This is the area where heavy corrosion was found on therecovered air pipe head from the Ievoli Sun. Once the thin coating has wornthrough, the steel is locally exposed and corrosion commences.

AHG/FDF also found from results of surveys that corrosion can occurbeneath the ball where this is normally resting on a galvanised steel surface.This may also be attributed to erosion. It is therefore recommended that aresting bar or bars or other device be introduced such as to prevent the ballfrom touching the inner chamber in its normal position.

AHG/FDF considered that zinc coating should be deposited on the air pipehead by the hot method, and should have a thickness of 70 – 100 microns.

For heads constructed from cast iron, a suitable epoxy or equivalent coatingshould be applied. For both types it was considered that a harder coatingshould be used in areas which could be susceptible to erosion when ballastwater is pumped through.

AHG/FDF further considered that a minimum thickness of 6 mm should bespecified for the inner and outer chambers of an automatic air pipe head.

vi) Improve the seal between the vent arrangement and seat.Members considered UR P3.2.3 and P3.2.7 covered this.

vii) Improve the design to facilitate inspection and maintenance.Members considered UR P3.2.2 covered this.

4. Recommendations for consideration into UR P3

AHG/FDF suggest that consideration be given to the following items forpossible inclusion into UR P3:

i) provision of bars or cage or other device for preventing the ball or floatfrom contacting the inner chamber in its normal state,

ii) for galvanised steel air pipe heads, the zinc coating to be applied by thehot method, and the thickness to be 70 to 100 microns.

iii) for areas of the head susceptible to erosion (e.g. those parts directlysubjected to ballast water impact when the tank is being pressed up, forexample the inner chamber area above the air pipe, plus an overlap of 10º ormore either side) an additional harder coating should be applied. This maybe an aluminium bearing epoxy, or other equivalent, coating, applied over thezinc, and

iv) a minimum thickness of 6 mm for the inner and outer chambers of anautomatic air pipe head.

Part B, Annex 3

Technical Background for UR P3 Rev.3, Nov 2012

1. Scope and objectives To clarify the type-test method of P3 for tightness test and to evaluate tests to prove the ability to handle vacuum and criteria for the relationship area requirement and flow characteristics. 2. Engineering background for technical basis and rationale 2.1 With respect to the type tests of air pipe closing devices, the tightness tests for

such devices, in principle, should be performed under strict conditions such as having the opening facing upward, etc. based upon design requirements. Since the UR does not clarify any test method regarding the above, certain classification societies only require type test examinations to be carried out at an inclination of 40 degrees in a single fixed direction. However, performing the required testing for the device under such less restrictive conditions might influence the test outcome in a negative way.

Therefore, in order to carry out unified type tests for such devices under strict conditions, new specific type test conditions based upon the direction in which the opening of the device faces are needed as shown in Figure 1 to 4.

Fig 1: Normal position

Opening

Vertical

Fig 2: Inclination 40 degrees opening facing upward

Fig 3: Inclination 40 degrees opening facing downward

Opening

40 degrees

Opening

40 degrees

Vertical

Vertical

Fig 4: Inclination 40 degrees opening facing sideways

2.2 A problem exists in which the float of an air pipe closing device is sucked into the

opening by the negative pressure in the tank. As a result, the float is blocking the flow of air resulting from the typical emptying of tanks and may become damaged under these conditions.

Therefore, a new test item related to reverse flow is needed.

These are reflected in the revision of P3. 3. Source/derivation of the proposed IACS Resolution None 4. Summary of Changes intended for the revised Resolution: The original requirement in UR P3 is to be amended by revising the original paragraph P3.4.1 b) iii) and adding a new paragraph P3.4.1 c) as follows: Discharge / Reverse flow test is added The air pipe shall allow the passage of air to prevent excessive vacuum developing in to the tank. A reverse flow test shall be performed. A vacuum pump or another suitable device shall be connected to the opening of the air pipe leading to the tank. The flow velocity shall be applied gradually at a constant rate until the float gets sucked into the inlet of the air pipe and blocks the flow. The velocity at the point of blocking shall be recorded. 80% of the value recorded will be stated in the certificate. 5. Points of discussions or possible discussions All of the proposals were agreed to unanimously except for deleting P3.2.5, where several members argued that this general criterion which has been working well should be kept in order not to carry out the flow characteristic evaluation on each air pipe.

Opening

40 degrees

Vertical

One member argued that as P3.2.5 does not take into consideration the effect of grids and the inner geometry of the vent head it was proposed to delete P3.2.5 and include the following under P3.5. Product documentation: “Every vent head shall be delivered with the flow characteristic curve recorded during Type Testing (ref P3.4.1.a)”. However, this was not supported by the majority of the members. 6. Attachments if any None