Materials and Qualification Procedures for Ships Approval of Works for the Manufacture of Fusion Welded Pressure Vessels Revision 4, July 2015 Page 1 of 17
Lloyd s Register Group Limited, its subsidiaries and affiliates and their respective officers, employees or agents are, individually and collectively, referred to in this clause as Lloyd s Register. Lloyd s Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Lloyd s Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract. Lloyd's Register Group Limited 2015. All rights reserved. Except as permitted under current legislation no part of this work may be photocopied, stored in a retrieval system, published, performed in public, adapted, broadcast, transmitted, recorded or reproduced in any form or by any means, without the prior permission of the copyright owner. Enquiries should be addressed to Lloyd's Register Group Limited, 71 Fenchurch Street, London, EC3M 4BS. Page 2 of 17
Approval of Works for the Manufacture of Fusion Welded Pressure Vessels 1 General Information 1.1 Application for approval 1.1.1 In order that consideration may be given to Lloyd s Register s (LR s) approval of works for fusion welded pressure vessels for marine use, the Surveyor is to arrange an inspection of the works, make an assessment of the capabilities, and submit a report to Headquarters (Materials and NDE Department), giving details of the manufacture s facilities and organisation and the results of tests carried out under survey. 1.1.2 Upon satisfactory review of this report by Materials and NDE Department, the works will be approved for fusion welding of pressure equipment in accordance with LR s Rules and Regulations for the Classification of Ships (hereinafter referred to as the Rules for Ships) and the Rules for the Manufacture, Testing and Certification of Materials (hereinafter referred to as the Rules for Materials). The name of the works will be entered in List 12 - Fusion Welded Pressure Vessels of LR s List of Approved Manufacturers of Materials, Recognized Proving Establishments and Class 1 Welding Firms (hereinafter referred to as the List of Approved Manufacturers). 1.2 Scope 1.2.1 This procedure applies to approval of works for fusion welded pressure vessels and boilers manufactured in accordance with LR s Rules for Materials. 1.2.2 This procedure gives guidance on the initial approval of works, and for subsequent continuation and upgrading of approval. 1.2.3 This procedure covers the requirements for approval of firms for manufacture of pressure vessels in classes: Class 1, Class 2/1 and Class 2/2. 1.2.4 Requirements for Class 3 approvals are not covered in this Procedure. Approval to this Class is subject to the agreement of the local LR office and no referral to Materials and NDE Department is required. 1.2.5 The firm approved to a higher class is automatically approved for the manufacturing of pressure vessels to lower classes. For example, Class 1 firm is also approved for the manufacturing of Class 2/1 & Class 2/2 pressure vessels. Page 3 of 17
1.2.6 Approval guidelines are related to carbon, carbon-manganese and alloy steels. However, approval for vessels manufactured from other metallic materials will be subject to agreement with Materials and NDE Department. 1.2.7 The inclusion of a works in the List of Approved Manufacturers is intended for those manufacturers who produce high quality pressure vessels, maintain the necessary equipment to do so, and have a formal quality control organisation and a responsible attitude to quality. In general, manufacturers will not be included in the Approved List unless they have available appropriate mechanical testing and NDE facilities, and heat treatment furnaces 1.3 Related Rules 1.3.1 This procedure is in accordance with the requirements of LR s Rules for Materials. The relevant chapters from the Rules include : Pt 5, Ch 10 - Steam Raising Plant and Associated Pressure Vessels. Pt 5, Ch 11 - Other Pressure Vessels. Pt 5, Ch 12 - Piping Design Requirements. Pt 5, Ch 17 - Requirements for Fusion Welding of Pressure Vessels and Piping. Ch 12 & 13 of Rules for Materials 1.4 Definitions 1.4.1 Essential parameters are manufacturing parameters, required to be controlled in order to maintain the quality of the completed pressure vessel (e.g. welding processes, material types etc.). 1.4.2 Approval class is equivalent to the pressure vessel class as determined from the pressure, temperature, size, contained fluids and gases, defined in Pt 5, Ch 10, 11 and 12 of the LR Rules for Ships. Page 4 of 17
2.0 Approval procedure 2.1.1 On receipt of an application from a manufacturer, the local Surveyor is to arrange a visit to the works to make an initial assessment of the work s facilities and quality system, and to discuss the reasons for the application. 2.1.2 The Surveyor should confirm that the manufacturer is capable of achieving LR s requirements for the approval class sought. 2.1.3 If both parties agree to proceed, the facilities are to be subjected to a fuller inspection as detailed in this procedure, and results reported to Materials and NDE Department. 2.1.4 Preliminary weld tests are required to be performed and witnessed, and the Surveyor is to arrange with the manufacturer for these tests to be carried out. Where approval is sought for non-ferrous materials, (e.g. material Group C), then Materials and NDE Department are to be consulted to confirm the scope of testing required. 2.1.5 It is implicit that for Class 1 approval, the manufacturer demonstrates acceptable design capability in accordance with the Rules for Ships and the Rules for Materials. 2.1.6 Additionally for Class 1 approval, the Surveyor is to carry out inspections and witness tests during manufacture of an actual vessel considered equivalent to LR Class 1. 2.1.7 The detailed works inspection report, results of preliminary tests, manufacturing inspections and tests, and design reviews (see 2.1.3, 2.1.4, 2.1.5 and 2.1.6 ) are to be submitted to Materials and NDE Department. It is recommended that the Surveyor submits the results as they become available, and not wait for the completion of all tests and inspections. 2.1.8 All relevant reports and test results are to be reviewed by Materials and NDE Department, and if the application is considered satisfactory, a certificate of approval is to be issued. An entry will then be made in List 12 of LR s List of Approved Manufacturers. 2.1.9 Approved works are to be subject to re-inspection at a period not exceeding Page 5 of 17
three years. 3.0 Information required for initial approval 3.1 Initial assessment and report 3.1.1 The following information is to be supplied by the manufacturer in all cases: (a) Product details and class of approval sought. (b) Name and address of the works, how long it has been established and the type of vessels previously manufactured. (c) The design codes or standards and materials used for construction. (d) The estimated total annual production of vessels. (e) The types of materials for which approval is sought and the maximum thickness. (f) The welding processes to be used. 3.1.2 The Surveyor is to prepare a Report on the following aspects of the manufacturer s facilities on LR s standard report format Form 1123 (LR General) [available in LRForms2] : (a) The manufacturing facilities available, fabrication shop size, whether protected from the weather, crane capacity, material storage etc. (b) The facilities for the preparation and inspection of cut edges. (c) Details of forming equipment for shells and heads. (d) Details of preheating and post-weld heat treatment equipment and furnaces, including methods of heating and temperature measurement. (e) The availability and range of welding procedures and welder s qualifications. (f) The facilities available for welding, including the number and type of Page 6 of 17
welding machines and the facilities for welding consumable storage. (g) Details of facilities for non-destructive examination and the equipment available, viewing facilities for radiographic examination and qualification of personnel. (h) The facilities for performing mechanical testing, the type of equipment, capacities and current calibration status. (j) Facilities and equipment for pressure testing. (k) The efficiency and competence of the manufacturing workforce. Where any of the above activities are subcontracted, the Surveyor is to perform an inspection of the subcontractor s works. 3.1.3 The following information related to the quality management system and working practices is to be reported : (a) A description of the organization indicating the relationship between the production management and the quality assurance and quality control departments. This may be in the form of an organisation chart. (b) The numbers of personnel employed in direct inspection activities. (c) The name and qualifications of the person(s) who has overall responsibility for quality control and technical control of welding. 3.1.4 Included in the report in 3.1.2 and 3.1.3 are to be the Surveyor s recommendations as to the suitability of the works, and subcontractors (where used), to produce work of the required quality. An original of the report is to be submitted to Materials and NDE Department for review. Page 7 of 17
4.0 Approval test programme 4.1 Preliminary test plates 4.1.1 Preliminary test plates are required for all approval classes. As approval is based on material type, thickness, welding process and heat treated condition, the preliminary welding tests are to be performed to reflect each of these conditions. 4.1.2 Tests are to be prepared from plate material of the same type for which approval is sought. The thickness is to be equal to the maximum for which approval is sought, and in the case of carbon steels this is not be less than 20 mm. 4.1.3 The test joint configuration and welding conditions are to simulate, as far as possible, those used for vessel longitudinal seams. 4.1.4 Test plates are to be subjected to destructive and non-destructive tests in accordance with the requirements of Section 4, Chapter 13 of Rules for Materials. These requirements are summarized in Table 0-4.4.1. Page 8 of 17
Table 0-4.4.1 Preliminary and routine tests, NDE and mechanical tests. Tests Required for Approval Class 1 Class 2/1 Class 2/2 NDE (see Notes 1) All weld metal tensile (see Note 2) Transverse tensile Bend tests (see Note 4) Charpy impact tests: Weld metal Heat affected zone (FL and FL+ 2 mm ) (see Note 5) Macro examination Visual and Radiography Visual and Radiography Visual 1 1 (see note 3) 2 2 1 1 root 1 face 1 set of 3 (see Note 6) 1 root 1 face (see Note 7) (see Note 7) 1 root 1 face (see Note 7) (see Note 7) 1 1 1 Hardness survey (see Note 8) 1 1 Not required Chemical analysis of weld 1 1 Not required Weld ferrite & Corrosion tests for austenitic/ duplex materials See Note 9 See Note 9 See Note 9 Notes 1. Visual examination may be supplemented by magnetic particle or dye penetrant examination at the request of the Surveyor. 2. Where more than one welding process or filler metal has been used, tests are required from each area of the weld, except those processes or filler metals used solely for the root weld. 3. All weld metal tensile required where the welding consumable is not LR approved. 4. Root and face bends may be substituted by side bends where the material thickness exceeds 12mm. 5. Refer Figures 12.2.6 & 12.2.7, Chapter 12 of Rules for Materials for specimen locations. 6. HAZ impact tests specimens may be omitted where minimum design temperature is above +20 C. 7. Impact tests specimens are required where the design temperature is below -10 C. 8. Hardness surveys are required for carbon steel boiler grades with a tensile strength of 460N/mm 2 and above (Ch 3,4.0 of the Rules for Materials), all Cr- Mo grades, and all low temperature (LT-xxxx) grades (Ch 3,6.0 of the Rules for Materials). 9. Refer Section 3, Chapter 12 of Rules for Materials. Page 9 of 17
4.1.5 The test plates are to be subjected to a simulated heat treatment, prior to testing, where the approval range sought is such that post-weld heat treatment (PWHT) is required for the actual vessels to be manufactured. 4.1.6 The results of all preliminary tests are to be forwarded to Materials and NDE Department for review. The welding processes used, the material types, material thicknesses and the heat treated condition are to be reported for each test. Results may be reported on the manufacturer s format or in accordance with LR s Report on the Approval of Works for the Manufacture of Fusion Welded Pressure Vessels Results of Preliminary and Routine Tests (Form 5506) [available in LRForms2]. 4.2 Manufacturing inspections and tests (Class 1 approvals) 4.2.1 Where the application relates to Class 1 approval, the following inspections and weld tests are required to be performed in addition to the preliminary tests referenced in 4.1. 4.2.2 Inspections during the manufacture of an actual vessel that is considered equivalent to LR Class 1, should include, as a minimum : (a) (b) (c) pressure testing; heat treatments; and non-destructive examinations. 4.2.3 Routine test plates are required to be performed in accordance with Section 4, Chapter 13 of Rules for Materials. Test plates are to represent vessel longitudinal seams and are to be welded as extensions to these. For spherical vessels, separate test plates are permitted. 4.2.4 For each material group for which approval is sought, at least two routine test plates are to be subjected to mechanical testing. Tests are to be chosen to represent different welding processes for which approval is sought. 4.2.5 The tests required are to be in accordance with the requirements of Section 4, Chapter 13 of Rules for Materials, as summarized in Table 0-4.4.1. 4.2.6 Prior to mechanical testing, test plates are to be subjected to PWHT, if the actual vessel requires it. 4.2.7 The manufacturer is to submit a sample Class 1 pressure vessel design to the concerned LR Design Appraisal office, or to Engineering Systems of Marine Technology & Engineering Services in Global Technology Centre UK for review (noting that any fees chargeable for this service are to be agreed in advance). Evidence is to be provided that the design has satisfied LR s Rules for Ships. This may take the form of a Design Appraisal Document (DAD). Page 10 of 17
4.2.8 The results of the inspections and tests referenced in 4.2.2, 4.2.3 and 4.2.7 are to be submitted to Materials and NDE Department for review. Page 11 of 17
5.0 Approval certificate and range of approval 5.1 Approval certificate 5.1.1 Materials and NDE Department will review the inspection reports and results of tests required for approval. 5.1.2 Upon satisfactory review, a certificate will be issued by Materials and NDE Department stating the range of approval as detailed in 5.1.3, and an entry will be made in LR s List of Approved Manufacturers as follows : Class 1 approvals - List 12a Class 2/1 approvals - List 12b Class 2/2 approvals - List 12c (Class 3 approvals will not appear in the List of Approved Manufacturers) 5.1.3 The approval certificate is to specify the range of approval for the essential parameters as detailed 5.2.1 to 5.2.6. 5.2 Approval range 5.2.1 Manufacturing location. Approval will be granted to the works where the inspections and weld tests were performed. Should a manufacturer require approval for several manufacturing plants, each is to be subject to approval in accordance with this procedure. 5.2.2 Material type. Approval is based on the material types used for preliminary test plates and are divided into the following three approval groups: Group A Group B Group C - Carbon, and carbon/manganese and low alloys steels. - High alloy steels (e.g. austenitic stainless steels). - Other metallic materials (e.g. aluminium, copper alloys). 5.2.3 Material thickness. For each material type, the approved thickness is based on the thickest preliminary test plate for which satisfactory results were reported. 5.2.4 Welding processes. The welding processes approved are based on those which gave satisfactory results during preliminary testing (e.g. submerged arc welding (SAW), shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW)). 5.2.5 Heat treated condition. This will be limited to that for which satisfactory results from preliminary tests were reported (e.g. as-welded or PWHT). 5.2.6 Minimum impact test temperature. For each material type, the minimum impact test temperature is to be that for which satisfactory results during preliminary testing were reported. Where no impact tests were performed, Page 12 of 17
no value will be specified on the certificate. Note that the test temperature will, in many cases, be different from the vessel minimum design temperature. Page 13 of 17
6.0 Upgrading and extension of approval 6.1 Extension of approval 6.1.1 Extension of approval is considered to be where the manufacturer wishes to extend the ranges of the essential parameters specified in 5.2. 6.1.2 Where the manufacturer requests extension to the approval range, consideration will be given when the necessary tests and inspections have been performed that ascertain the suitability of the firm for this extension. 6.1.3 The Surveyor is to inspect the works and arrange for preliminary tests to be performed in accordance with Section 4, appropriate to the new range for which approval is sought. 6.1.4 The results of the preliminary tests and inspections are to be forwarded to Materials and NDE Department for consideration. 6.1.5 A new certificate will be issued by Materials and NDE Department upon satisfactory review. The validity date shall remain unchanged from the approval currently held by the works. 6.2 Upgrading of approval 6.2.1 Upgrading of approval is considered to be where the manufacturer wishes to upgrade the approval class to a higher one (e.g. from Class 2/2 to Class 2/1). 6.2.2 The Surveyor is to inspect the works and assess whether the manufacturer is suitable for this upgrading. 6.2.3 The appropriate preliminary tests are to be performed as required by 4.1. Previous tests, performed under survey, which meet the requirements of the higher approval class may be considered for acceptance. 6.2.4 In addition, where upgrading to Class 1 is requested, the following inspections and tests are required : (a) Inspections on actual vessels as detailed in 4.2.2. (b) Routine test plates in accordance with 4.2.3 to 4.2.6. (c) Assessment of design capability in accordance with 4.2.7. 6.2.5 Results of the inspections and tests are to be submitted to Materials and NDE Department for review. Should the results be considered satisfactory, an approval certificate will be issued and a new entry made in the List of Approved Manufacturers. The certificate is to be considered as a new initial approval and the anniversary date for renewal will be amended to reflect the new issue date. Page 14 of 17
6.3 Transfer of approval 6.3.1 Transfer of approval will be considered where the manufacturer wishes to move its manufacturing facilities to a new location not previously approved. 6.3.2 Transfer of approval will be considered subject to the Surveyor being satisfied that the quality of workmanship remains satisfactory. 6.3.3 The Surveyor is required to review the new manufacturing plant and management structure in accordance with 3.1.2 and 3.1.3, and report any changes to Materials and NDE Department. 6.3.4 It is required that the manufacturer demonstrates the weld quality has not been affected as a result of the transfer. Preliminary or routine test plates appropriate to the class of approval are to be performed in accordance with 6.3.5 and 6.3.6. 6.3.5 Where the Surveyor considers that the transfer has affected either the quality of workmanship (e.g. changes to the working practices), or the effectiveness of the production operatives, the full range of preliminary tests are to be performed in accordance with 4.1. 6.3.6 Where the Surveyor is satisfied that the quality of workmanship remains unchanged, a reduced scope of testing may be permitted. In this case, routine tests are required and the test programme is to be devised such that these represent as much of the approval range as possible. As a minimum, each material group approved and each welding process approved is to be included in the test programme (noting that each welding process need not be tested on each material group). Test plates are to be subjected to testing in accordance with Table 0-4.4.1, appropriate to the approval class. Page 15 of 17
7.0 Continuation of approval 7.1 General 7.1.1 The approval certificate is valid for a period of three years. Continuation of approval is to be dependent on the firm demonstrating that the quality of workmanship has not significantly altered since the original approval. 7.1.2 The Surveyor will be required to visit the works and carry out inspections during the course of manufacture of vessels, or where the firm notify him of any changes in the quality system or working practices, or where it comes to the Surveyor s notice that the quality of work has deteriorated. In any event, for Class 1 and Class 2/1, the Surveyor is to visit the works at least once every year. (Note that Materials and NDE Department will only issue reminders approx. 3 months prior to the certificate expiry date.) 7.1.3 The works inspection is to highlight any additions, deletions or any changes in the works and facilities as follows: (a) (b) (c) (d) (e) (f) The condition of the works and facilities. The quality of the workmanship. The quality control organisation and key personnel. The qualification of personnel. Testing and NDE equipment condition and calibration. Welding processes used. 7.1.4 Every three years, the Surveyor is to perform a re-approval inspection of the works, as in 7.1.3, and submit the report to Materials and NDE Department for review. The number and types of vessels produced in the intervening three years (including those to LR Class) are to be reported. Results are to be reported on the Inspection Report for Re-Approval of Works for Class 1 and 2/1 Fusion Welded Pressure Vessels (Form 5504) [available in LRForms2] and the Inspection Report for Re-Approval of Works for Class 2/2 Fusion Welding of Pressure Vessels (Form 5505) [available in LRForms2]. Copies of any intermediate inspections (see 7.1.2) may be included with the re-approval report. 7.1.5 In the event that the works have not produced any pressure vessels in the validity period of the certificate, consideration should be given to having preliminary tests performed as required by 4.1. 7.1.6 In the event that the works have not had any inspections or tests performed under LR survey during the validity period of the certificate but have had vessels manufactured under survey by another third party authority, then a review of manufacturing and quality control records of these vessels is to be completed by the surveyor. Typically this would involve the following: Page 16 of 17
NDE results Pressure test results Routine tests results Sufficient records should be reviewed to fully cover the existing scope of approval. 7.1.7 In the event that the manufacturer has not had any third party inspections during the validity period, consideration should be given to completing testing as per 6.3.4. 7.2 Certificate renewal 7.2.2 Should re-approval be granted, a renewed certificate is to be issued with the range of approval unchanged, and the validity period extended for another three years. Page 17 of 17