REVIEW OF DECISION TO DEREGISTER PLANT DESIGN

THE OCCUPATIONAL SAFETY AND HEALTH TRIBUNAL

CITATION : 2017 WAIRC 00375

DELIVERED : THURSday, 29 JUNE 2017

FILE NO. : OSHT 5 OF 2016

Applicant

AND

Lex McCulloch WorkSafe Western Australia Commissioner

Respondent

Catchwords : Industrial Law (WA) - Occupational Safety and Health - Application for review of decision to deregister plant design - Principles applied - Units fall within the extended definition of boiler for the purposes of Reg 4.1 - The design alteration in relation to the gas side chambers of the Units meets the requirements for registration and is consistent with sound engineering practice - Altered design is limited to Units at Fiona Stanley Hospital - Exemption requests should be granted - Application to review allowed

Legislation : Industrial Relations Act 1979 (WA)

  Occupational Safety and Health Act 1984 (WA) ss 5, 61A

  Occupational Safety and Health Regulations 1996 (WA) Regs 4.1, 4.2, 4.3, 4.7, 4.12

  Interpretation Act 1984 (WA)

Result : Application to review allowed

Representation:

Counsel:

Applicant : Mr S Russell of counsel and with him Mr R Stephenson of counsel

Respondent : Ms T Hollaway of counsel

Solicitors:

Applicant : Macpherson Kelley

Respondent : WorkSafe WA, Department of Commerce

Case(s) referred to in reasons:

Project Blue Sky Inc v Australian Broadcasting Authority [1998] HCA 28; (1998) 194 CLR 355

Re Dr Ken Michael AM; Ex parte Epic Energy (WA) Nominees Pty Ltd & Anor [2002] WASCA 231

The WorkSafe Western Australia Commissioner v The Original Croissant Gourmet Pty Ltd [2007] WAIRC 01273; (2007) 88 WAIG 22

Wormald Security Australia Pty Ltd v Peter Rohan, Department of Occupational Health, Safety and Welfare (1992) 74 WAIG 2

Reasons for Decision

The application

1         The applicant, Exhaust Control Industries Pty Ltd is engaged in the business of designing pollution and noise control products for domestic and international customers. The respondent, WorkSafe, is the general occupational health and safety regulator in Western Australia.

2         In July 2011 ECI commissioned a company named Shearform Pty Ltd to fabricate two waste heat recovery units. The Units were manufactured and delivered to Triple M Mechanical Services and were installed at the Fiona Stanley Hospital in Murdoch, south of Perth. The Units operate by receiving exhaust gases from natural gas engines and generating steam for use in the hospital.

3         The design for the Units was registered with WorkSafe in December 2013.  In the course of 2015, a number of issues were raised by WorkSafe with regard to the design of the Units.  Design verification was undertaken by consultants to ECI.  Amendments to the design were developed and submitted to WorkSafe in August 2015. Concerns about the welds used on the Units were the subject of an independent report in September 2015.

4         Also in September 2015, the design amendment for the Units was registered by WorkSafe. A number of issues were canvassed between the parties from late 2015 until early 2016. In March to April 2016 ECI lodged requests for exemption from compliance with the Occupational Safety and Health Regulations 1996 (WA) and revised requests for exemption with WorkSafe.

5         By mid-2016, ECI had obtained confirmation from Shearform that the welds used on the Units were in accordance with the relevant Australian Standards and in accordance with the Unit design. WorkSafe were informed of this.

6         By letter of 5 September 2016 WorkSafe informed ECI of its decision that the design registrations for the Units be deregistered.  There were five stated grounds for the deregistration.  They were:

(a) The internal inspection access opening requirements of the Units do not comply with Cl 3.9.5.2(c) of AS 1228-2006;

(b) The non-destructive testing on the Units show the welds being inconsistent with the design drawings, by being fillet and not butt welds as required;

(c) The low water level cut-off arrangements do not meet the AS 1228-2006 requirements;

(d) The design verification for the Units was done two years’ post-manufacture and therefore was not performed on an “as manufactured” basis which would have shown non-compliance with AS 1228-2006; and

(e) The use of AS/NZS 3678-250 steel plates in the manufacture of the Units is not designed to exceed 250°C. The maximum temperature as per the ECI Operations and Maintenance Manual of 475°C for exhaust gases, constitutes a significant deviation from the design conditions allowed for in AS 1228-2006.

7         On the above basis, WorkSafe considered the Units were a safety risk and it was therefore necessary to deregister the designs under Reg 4.7(2) of the Regulations.  ECI now challenges the decision of WorkSafe by way of an application for review to the Tribunal under s 61A of the Occupational Safety and Health Act 1984 (WA). Whilst the application for review was outside of the time prescribed for a referral to the Tribunal under s 61A(2) of the Act, WorkSafe did not oppose an extension of time sought by ECI and the Tribunal granted it.

Grounds of review

8         The grounds of the application to review are set out at schedule B to the application which is in the following terms:

Schedule B

Application for review

1. The Applicant seeks review of the Decision of the Commissioner for the following reasons. Reliance is made on the affidavits of Wolfgang Mika and Syed Shah.

Internal inspection access opening requirements

2. The requirement for internal inspection access openings pursuant to Clause 3.9.5.2(c) of Australian Standard 1228-2006 Pressure Equipment - Boilers is no longer the only means of visually inspecting the internal components of the Units. Historically, physical sighting of the internal parts through openings in boilers was the only means of internal inspection.

3. The use of remote cameras to inspect the Units is a simple method of achieving the same outcome as installing visual inspection openings in the Units.

Non-destructive testing (NDT)

4. The concern that WorkSafe had concerning the 'butt' welds arose due to a clerical error. The evidence established that Shearform Pty Ltd, conducted the correct 'butt' welds in accordance with the design drawing requirements, but made a clerical error and documented these welds as 'fillet' welds.

Low Water Level Cut Off

5. The concern expressed by WorkSafe that the nominated low water level cut-off arrangements do not meet nominated design standard AS1228-2006 can be resolved by amending the low water level cut-off settings on-site.

Design Verification

6. The Units have been the subject of two designs, which were registered as numbers WAP22731 and WAP23564. The more recent design acknowledges the presence of a pressure relief valve on the exhaust gas side of the Units. As a result, the 'as manufactured' drawings were amended and the design verified accordingly.

AS3678-250 Steel Plates

7. The concern expressed by WorkSafe concerning the steel plates arises from a misunderstanding by WorkSafe as to the definition of 'boiler' contained in Regulation 4.1 of the Occupational Safety and Health Regulations 1996 (OSH Regulations). Only the part of the Unit that produces steam can be defined as a boiler. The gas side chambers at each end of the Units, which receive and expel exhaust gasses, cannot be said to be boilers.

8. Regulation 4.1 of the OSH Regulations defines a 'boiler' as a 'vessel or an arrangement of vessels and their interconnecting parts in which steam or other vapour is generated’. The gas side chambers at each end of the Units do not generate steam or any other vapour.

9. Relying upon the proper assessment of the boiler components, the gas-side chambers comply with the relevant Australian Standard.

10. The Units can be operated safely and do not pose a safety risk.

Conclusion

11. With the use of universally available testing equipment and minor adjustments on-site, the Units comply with the relevant Australian Standard and accordingly the decision by the Commissioner dated 5 September 2016 cancelling registration of the two Units should be rescinded.

9         The Units are waste heat recovery units and are designed to recover heat from exhaust gas generated by a natural gas powered engine.  The general description of the operating principle of the Units appears in the Operations and Maintenance Manual (annexure 13.16 witness statement of Mr Rajah p 1283) in the following terms:

The WHRU is designed to recover heat from the exhaust gas stream from the natural gas powered reciprocating engine This heat recovery is achieved by passing the hot exhaust gases through a series of internal tubes, which conduct heat to the surrounding water the WHRU. This heat transfer cools the exhaust gases and heats the water. The cooled gases are discharged to atmosphere via the exhaust ducting downstream of the WHRU. The heated water boils to steam and the steam is drawn off the top of the unit and piped away for use. The level of water is automatically controlled in the WHRU over a normal operating range by the addition of water using the feedwater pumps. The water and steam are contained within the WHRU in a vessel bounded by the shell, the two tube sheets and the tubes. These parts form the pressure envelope.

Control of the amount of heat provided to the WHRU is achieved with the bypass damper. This damper serves to re-direct part of the exhaust gases directly from the inlet of the WHRU to the outlet, thereby reducing the proportion of the hot gases that pass through the heat transfer tubes within the WHRU vessel. The position of this bypass damper is automatically set by the control system (by others) to match the quantity of steam being produced to the demand.

The WHRU also reduces engine exhaust noise.

10      A copy of a diagram of the Units, taken from the Bureau Veritas Technical Note Boiler Parts – Clarification (annexure WJM1A to the affidavit of Mr Mika 16 February 2017) is annexure 1 to these reasons.

11      The design temperature for the exhaust gas side of the Units (grey shaded areas on annexure 1) is to a maximum temperature of 475°C and to a maximum pressure of 37kPa regulated by a pressure relief valve. The steam side of the Units (blue shaded areas on annexure 1) in which are located tubes through which exhaust gases pass, has a design temperature maximum of 250°C. The maximum design pressure of the steam side of the Units is 1034kPa. A safety valve is also fitted to regulate this pressure.

12      Each Unit has a removable end cover intended to provide maintenance access to the tube sheets and the internal services of the gas path. However, as the Tribunal observed from an on-site inspection of the Units at Fiona Stanley Hospital, access to the end covers and their removal, has some difficulties associated with it. The Units have not been operating at Fiona Stanley Hospital since their initial commissioning, because of the present dispute.

Regulatory scheme

13      It is convenient at this point to set out the statutory scheme under which the present application for review is brought. Section 61A of the OSH Act is in the following terms:

61A. Review of Commissioner’s decisions under regulations

(1) In this section —

reviewable decision means —

(a) a decision made under the regulations by the Commissioner himself or herself; and

(b) a determination of the Commissioner on the review, under the regulations, of a decision made under the regulations by a person other than the Commissioner, whether or not the decision was made by that person as a delegate of the Commissioner,

but does not include a decision made by a person acting as a delegate of the Commissioner.

(2) A person who is not satisfied with a reviewable decision may, within 14 days of receiving notice of the decision, refer the decision to the Tribunal for review.

(3) On reference of a decision under subsection (2), the Tribunal is to inquire into the circumstances relevant to the decision and may —

(a) affirm the decision; or

(b) set aside the decision; or

(c) substitute for the decision any decision that the Tribunal considers the Commissioner should have made in the first instance.

(4) Pending the decision on a reference under this section, the operation of the reviewable decision is to continue, subject to any decision to the contrary made by the Tribunal.

14      The relevant provisions of the Regulations in relation to plant are prescribed by Part 4.

15      Specifically, the registration of plant design and items of plant is prescribed by Division 2 of Part 4. By Reg 4.2 any person who manufactures, imports or supplies plant of a kind set out in Schedule 4.1, must ensure that the design of the plant has been registered by WorkSafe and that the plant has been manufactured in accordance with the registered design. Regulations 4.3 to 4.6 set out the process for application for registration of plant design and the requirements imposed. By Reg 4.7 WorkSafe may register the relevant plant design with or without modifications, or refuse registration. In this case the decision from which the review is brought, is a decision to deregister plant design rather than a decision to deregister an individual item of plant. Accordingly, WorkSafe relies on Reg 4.7, the power to approve and register plant design, read with the relevant provisions of the Interpretation Act 1984 (WA) to revoke such approval or registration. No issue is taken with this by ECI and I consider that WorkSafe had the statutory power to act as it did.

16      Additionally, Schedule 4.3 of the Regulations specifies Standards relating to the design and other requirements in relation to certain plant. The Schedule sets out various Australian Standards and items of plant. One of those Standards is AS/NZS 1200 in relation to pressure equipment (known as the SAA Boiler Code). The specification of plant set out in Schedule 4.1, and the relevant Australian Standards, are referred to in Division 2 of Part 4 of the Regulations.  Compliance with the Standards set out in Schedule 4.3 is required to be verified for the purposes of plant design registration.

17      Specifically, Cl 2.1 of AS/NZS 1200:2000 dealing with basic requirements and recommendations for pressure equipment, expressly incorporates by reference, other Standards that are required to be complied with in relation to the construction and use of pressure equipment. Those further Standards, set out in Table 2.1 and Appendix G of AS/NZS 1200:2000, refer to Standards relevant to these proceedings, including AS 1228-2006 in relation to boilers, and AS 1210-2010 in relation to pressure vessels generally. It is in this way, through the cascading operation of the relevant Standards, when read with Schedule 4.1, that they obtain legal force and effect under the OSH Act and the OSH Regulations.

18      Accordingly, the only way in which a person may depart from the requirements of the relevant Standards as set out in Schedule 4.3, to the extent that they apply, is to seek an exemption from WorkSafe under either Reg 2.12 or 2.13. Such an exemption may be granted with or without conditions. As noted, exemptions are sought in this case. Although supported by WorkSafe, the Tribunal, given the terms of s 61A of the OSH Act, will need to be satisfied that they should be granted.

The evidence

19      The basis for WorkSafe’s decision to deregister the plant design for the Units and their plant registrations, was referred to in the witness statement of Mr McCulloch, the WorkSafe Commissioner. Mr McCulloch explained the process of plant and design registration, as undertaken by the Business Services Directorate of WorkSafe. It is only in complex cases, that the engineering expertise from the Health Hazards and Plant Safety Directorate is sought, prior to registration of plant and design.

20      Whilst not stated by Mr McCulloch, it is to be inferred in this case that no issues of complexity were identified, as the concerns of WorkSafe were not raised until sometime after the registration of the design and plant. It is also the case in this matter, somewhat unusually, that the plant design registrations were not lodged for registration until some two years or thereabouts, after the manufacture of the Units. Thus, in this case, the design registrations as lodged, should have been on an “as manufactured” basis.

21      Mr McCulloch referred to meetings he had with the director of the Health Hazards and Plant Safety Directorate and with Mr Rajah, the Plant and Engineering Manager for WorkSafe. In June 2016, Mr McCulloch directed Mr Rajah to prepare a report on the Units at Fiona Stanley Hospital, because of some safety concerns identified.  A copy of Mr Rajah’s report with its annexures, was LM 1 to Mr McCulloch’s witness statement. Having considered the content of Mr Rajah’s report, and in reliance on his engineering expertise, Mr McCulloch reached the view that both the plant design and plant registrations themselves should be revoked on the grounds of non-compliance with the Regulations and relevant Standards, and on general safety considerations.

22      The background to the current dispute is set out in the witness statement of Mr Rajah who was also called by WorkSafe as an expert witness. Mr Rajah has had 27 years’ experience with WorkSafe and holds a Bachelor of Science in Engineering and a Postgraduate Diploma in Environmental Impact Assessment. Mr Rajah has very extensive experience in relation to high risk plant design assessment and review and inspection. Mr Rajah is a Chartered Professional Engineer and a member of relevant professional bodies.

23      In about August 2014 Mr Rajah had cause to request a senior WorkSafe inspector, Mr Rennie, to visit the Fiona Stanley Hospital to undertake a High Risk Work Licence requirement assessment for the Units. Following Mr Rennie’s inspection of the Units at the hospital, further concerns were raised in relation to the design and manufacture of the Units, leading to a full audit being prepared by Mr Rennie dated 20 November 2014. The upshot of the audit undertaken by Mr Rennie was his recommendation that the Units be deregistered on safety grounds. After Mr Rennie’s recommendation, WorkSafe requested the manager of the hospital, Serco Asia Pacific, to undertake an independent assessment and review of the safety of the Units.  Mr Martin Ford of WSP Parsons Brinckerhoff was duly commissioned to undertake the assessment and a preliminary report was provided to WorkSafe which was dated 1 March 2016. The report was annexure R5 to Mr Rajah’s witness statement.

24      Mr Rajah referred to the original design registration WAP22731 for the Units which specified a maximum inlet gas temperature of 250°C. This was subsequently the subject of an alteration to the design registration under Reg 4.12 of the Regulations, lodged in September 2015. The additional design detail in relation to the alteration specified a change to the maximum inlet gas temperature to 475°C and a reduction in the “tube side” design pressure to 37kPa.

25      The design amendment was accompanied by a letter dated 21 August 2015 from HRL Technology Pty Ltd on behalf of ECI, and provided calculations for the revised design conditions in relation to the gas inlet temperature and pressure. A copy of this letter with attached calculations was annexure R6.1 to Mr Rajah’s witness statement. Further, BV provided a design verification for the alteration attached at annexure R6. HRL noted in its letter of 21 August 2015 in relation to the revised design conditions that:

It must be mentioned here that because the revised internal design pressure for these components is below 50kPa the compliance of the design to AS1210-2010 Pressure vessels code is not applicable.  This may be similar for the revised design to AS 1228-2006 Pressure equipment – Boilers.  However, it was decided that the design for the above components for the revised design conditions be performed as good practice.

The drum ends are manufactured from AS3678-250 carbon steel plate for which higher temperature design strength properties are not available.  AS1210 – provides data up to temperature of 350°C, consequently the design strength was extrapolated for the design temperature of 475°C and factored down in accordance with AS1228.

The components were found to comply with the strength requirements of AS 1228-2006 Pressure equipment – Boilers, for the design strength used.  Calculations are attached.

26      Mr Rajah’s evidence was that he was concerned that HRL did not also consider the external pressure of 1034kPa acting on the boiler plain tubes.  Mr Rajah took the view that HRL “did not adopt a holistic approach as required under Reg 4.12.” Furthermore, Mr Rajah’s evidence was that he did not consider HRL’s extrapolation of the parameters from AS 1228-2006 to support the use of AS/NZS 3678-250 steel plates for temperatures of up to 475°C, to be prudent engineering practice. As noted by Mr Rajah, given there were design alterations made and registered in relation to the Units, the Units themselves needed to be the subject of re-registrations. However, these matters were put on hold pending the resolution of the issues raised by Mr Ford in the PB report.

27      Specifically, the Tribunal notes that from the PB report, issues were identified for resolution. Of relevance for present purposes, is the item appearing at pp 10 - 11 of annexure R5 to Mr Rajah’s witness statement. That concerns the design temperature for the Units in accordance with the design registration amendment referred to immediately above. Mr Ford notes three issues in relation to what he described as the “uncooled shell extensions”. Those three issues were:

(a) potentially high secondary stressors at the shell to tubeplate weld;

(b) the use of AS 3678 Grade 250 Plate at temperatures above that permitted by AS 1228-2006; and

(c) the acceptability of the design for coincident maximum gas temperature and a gas side pressure of 0.7MPa.

28      As to (a), Mr Ford said in his report “We maintain (sic) recommendation to ensure that the shell to tubeplate weld is inspected on a regular basis. Should be included in the vessel operating regime/maintenance strategy.” As to (b), the matter most apposite in relation to the narrowed matters in contention before the Tribunal, Mr Ford said “Shell extensions are not strictly ‘pressure parts’”. As to (c) Mr Ford said “The revised vessel design conditions have been reviewed and confirmed as appropriate by the system designer. Specifically – the gas side is protected by explosion vents designed to limit pressure to 37kPaG.  (closed)” (My emphasis).

29      The Tribunal will return to the views expressed by Mr Ford in relation to (b) concerning the design temperature and the observations of HRL referred to above, when considering the expert evidence.

30      After the conferral of Mr Rajah and Mr Mika as the parties’ expert witnesses, it is now accepted that the matters identified in the reasons for the revocation of the design registration, apart from the steel plate issue, can now be resolved by exemption from compliance with the Regulations, subject to ratification of the agreed position by the Tribunal. However, in relation to the use of AS/NZS 3678-250 steel, Mr Rajah maintained his view that for the gas side chambers of the Units to be exposed to operating temperatures in excess of 250°C, constituted a significant deviation from the design conditions allowed for in AS 1228-2006. Additionally, Mr Rajah expressed concern that the tube plate would also be exposed to exhaust gases at high temperature, which contributes to his view that there are significant safety concerns in relation to the current design and operational parameters for the Units.

31      Mr Rajah also expressed the view, whilst ultimately a matter of statutory construction, that the gas side chambers which constitute the heat source and gas discharge devices are integral to the operation of the boilers, and therefore the Units fall within the definition of a “boiler” for the purposes of Reg 4.1 of the Regulations. That this is so, is emphasised in Mr Rajah’s view, because without the gas inlet chamber, the Units could not operate as a boiler.

32      Mr Rennie has been the Senior Inspector (Pressure Equipment) at WorkSafe since 2002 and has been employed by WorkSafe since 1987. Mr Rennie holds qualifications in engineering (marine) and a Certificate of Competency as a First Class Engineer. During his employment with WorkSafe, Mr Rennie has been engaged in a range of work including high risk plant design assessment, review, fabrication, commissioning and inspection in situ of plant including pressure equipment, in relation to compliance audits and issuing Certificates of Inspection.

33      As noted by Mr Rajah, Mr Rennie initially had contact with the Units in August 2014, which prompted him to question compliance with the Regulations.  He undertook a desk audit following receipt of materials in relation to the Units from Serco, and concluded there were significant deficiencies in the document provided to him. It was from this audit that Mr Rennie formed his recommendation to Mr Rajah that the Units be deregistered on safety grounds.  One of the major concerns held by Mr Rennie related to the tube plate to shell welds following a review of site weld tests conducted by Australian Welding Academy Pty Ltd (Weld-Rite) on 20 November 2015. Following receipt of further material from Weld-Rite, Mr Rennie formed the view that the welds performed on the Units were fillet welds and not butt welds, as required by the appropriate Standard.

34      The findings of the desk audit undertaken by Mr Rennie were annexures IR1 to IR4 of his witness statement. Mr Rennie expressed concerns in the reports that the design verification process was flawed in material respects, and his conclusions in the audits supported his recommendation that the Units be deregistered.  Mr Rennie maintained that the gas side chambers to the Units must be regarded as “boiler settings” and thus form a part of the boiler design, which is required to comply with AS 1228-2006 and the definition of “boiler” in Reg 4.1 of the Regulations.

35      Mr Mika is the Principal Integrity Engineer at BV. Mr Mika holds a Bachelor of Mechanical Engineering and has over 20 years’ experience in risk based assessment, plant failure investigation, integrity assessment and performance improvement. Mr Mika has filed four affidavits in these proceedings. What follows is necessarily an overview of Mr Mika’s evidence.

36      In his initial affidavit filed in the application made to the Tribunal, Mr Mika responded to the grounds advanced by WorkSafe in its letter of 5 September 2016, setting out the reasons for the deregistration of the Unit designs. Whilst several of the issues for determination have fallen away, as the Tribunal will be required to form a view as to whether the exemptions as now supported by WorkSafe should be granted, it is necessary to traverse the evidence in relation to what now can be regarded loosely, as the supplementary issues. As to the first question of adequate inspection access of the Units, Mr Mika refers to the requirement of AS 1228-2006 at Cl 3.9.5.2(c) which requires that the Units have one small inspection opening in order that the internal parts of the Units can be visually inspected.

37      Mr Mika noted that at the time of the introduction of the relevant Standard, alternative means of internal inspection of items of plant such as the Units, were not available. Such alternative means now include remote camera technology. Mr Mika also referred to the significant cost to ECI if inspection openings are to be retroactively installed into the Units, and estimates approximately $25,000 in rectification costs in this regard. Mr Mika expressed the view that the use of remote camera technology for the purposes of internal inspection of the Units would be quite adequate. It is consistent with current practice in relation to internal inspection of other boilers and pressure equipment, with such camera technology being readily available.

38      I accept that evidence as referring to an alternative approach which accords with eminent common sense.

39      The next point relates to the non-destructive testing of the Units in relation to the weld maps supplied and assessed by WorkSafe, specifically whether the welds used on the Units were fillet welds or butt welds, as required by AS 1228-2006.  In referring to the relevant weld maps and non-destructive testing reports in relation to the Units, Mr Mika formed the view from these materials, and following discussions with Shearform Pty Ltd, the company who fabricated the Units, that the correct butt welds were performed in accordance with AS 1228-2006. However, the documentary records in relation to the welding procedures reflected an error and that error was not corrected in subsequent non-destructive testing on site.

40      Having regard to the evidence and the relevant Standards, the proposed course by the parties that ECI arrange for ultrasonic testing on the welds between the tube plates and shell of the Units, is also sensible. Such testing must confirm that the welds are full penetration butt welds in accordance with AS 1228-2006. It may not be necessary to undertake testing in respect of every relevant weld on the Units. The parties should confer in relation to agreeing upon a sample of ultrasonic testing, as it would seem to follow that if one test on the relevant welds on each of the Units reveals that they are in fact full penetration butt welds, it would be almost inevitable that the other relevant welds are also of the same kind. In my view, a WorkSafe inspector should be present during the testing process.

41      In relation to the low water level cut-off which relates to the cut-off settings on the Units’ water level indication and control equipment, Mr Mika’s evidence was that this can be overcome by an adjustment of the low water level cut-off settings. Mr Mika further testified that such adjustments may be made by the facility operators on-site and would be simple and inexpensive to undertake. I agree. The parties have not indicated that an exemption request would be required in relation to this issue, but having regard to the materials before the Tribunal, if one were required, it should be made and granted.

42      Whilst Mr Mika referred to the design verification issue referred to in the WorkSafe letter, Mr Mika testified that following ECI’s enquiries with the manufacturer of the Units, Shearform, he has been advised that the Units were constructed in accordance with the drawings used for the design verification undertaken by BV, and therefore represent the “as built” configuration of the Units. However, as the proceedings unfolded, this appeared to no longer be an issue requiring determination by the Tribunal.

43      On the question of the use of AS/NZS 3678-250 steel plates in the fabrication of the Units, Mr Mika, throughout his testimony, made some key points. The first was that WorkSafe had adopted an incorrect approach to the definition of a “boiler” for the purposes of Reg 4.1 of the Regulations. Mr Mika’s view was that the “boiler proper” is constituted by the central chamber of the Units which defines the pressure boundary and which contains both the water and the steam as generated. That is, in his view, it is the central pressure chamber which constitutes the boiler proper, and which does not include the gas side chambers at each end of the Units. As the gas side chambers to the Units do not contain water or steam, Mr Mika expressed the initial view that they could not be defined as a boiler or part of a boiler, for the purposes of Reg 4.1.

44      Accordingly, if that is so, then the use of AS/NZS 3678-250 steel in the fabrication of the gas side chambers, involves no contravention of AS 1228-2006. In any event, irrespective of this contention, given the subsequent design amendment to the Units, reducing the maximum exhaust gas pressure from 700kPa to 37kPa, the gas side chambers to the Units could no longer be regarded as “pressure vessels” in the terms of AS 1210-2010. An independent review of the exhaust gas system confirmed the maximum design pressure to be 37kPa.

45      Accordingly, it was Mr Mika’s professional opinion, that the Units as constructed, and as the subject of the design amendment, can be safely operated and pose no risk.

46      In further affidavit evidence, Mr Mika expanded and clarified a number of issues raised in the proceedings before the Tribunal, and as set out in the application. It was an overarching theme of Mr Mika’s testimony, that in his professional opinion based on all the material he has been provided by the fabricator of the Units, they have been designed and constructed to comply with the intention of each relevant Australian Standard. Where any departure is identified, such departure is justified by sound engineering practice and poses no risk to the safe operation of the Units.

47      Through adoption of the concurrent evidence approach, the issues in dispute have been very substantially narrowed. The parties now agree that the key issue for determination by the Tribunal, is whether the gas side chambers to the Units can be properly characterised as “pressure parts”, as defined in AS 4942-2001, for the purposes of AS 1228-2006. The provisions of AS 4942-2001 contain a glossary of terms relevant to pressure equipment generally, including boilers. Along with other Standards relevant to pressure equipment, AS 4942-2001 is clearly intended to be read as part of the scheme of Standards in relation to such equipment.

48      The issue that flows from this is whether the steel used for the construction of the gas side chambers, which is compliant with AS/NZS 3678-250, breaches the requirements of AS 1228-2006, in relation to the construction and operation of “boilers”.

Consideration

Approach to the review

49      In accordance with s 61A(3) of the OSH Act, the Tribunal is required to “inquire into the circumstances relevant to the decision” of WorkSafe. This involves, analogously with reviews of improvement and prohibition notices, the Tribunal assessing whether, in view of the material before it, WorkSafe was justified in making the decision it did. This requires the Tribunal to investigate for itself the circumstances giving rise to the decision and the validity of the conclusions reached: Wormald Security Australia Pty Ltd v Peter Rohan, Department of Occupational Health, Safety and Welfare (1992) 74 WAIG 2; The WorkSafe Western Australia Commissioner v The Original Croissant Gourmet Pty Ltd [2007] WAIRC 01273; (2007) 88 WAIG 22.

Principles of interpretation

50      The general approach to the construction of statutes, legislative instruments and other documents that may have legislative or regulatory effect, and contracts, is to construe the instrument as a whole. In Project Blue Sky Inc v Australian Broadcasting Authority [1998] HCA 28; (1998) 194 CLR 355, in the joint judgment of McHugh, Gummow, Kirby and Hayne JJ at par 69-70 and 78, it was said as follows:

69. The primary object of statutory construction is to construe the relevant provision so that it is consistent with the language and purpose of all the provisions of the statute[45]. The meaning of the provision must be determined "by reference to the language of the instrument viewed as a whole"[46]. In Commissioner for Railways (NSW) v Agalianos[47], Dixon CJ pointed out that "the context, the general purpose and policy of a provision and its consistency and fairness are surer guides to its meaning than the logic with which it is constructed". Thus, the process of construction must always begin by examining the context of the provision that is being construed[48].

70. A legislative instrument must be construed on the prima facie basis that its provisions are intended to give effect to harmonious goals[49]. Where conflict appears to arise from the language of particular provisions, the conflict must be alleviated, so far as possible, by adjusting the meaning of the competing provisions to achieve that result which will best give effect to the purpose and language of those provisions while maintaining the unity of all the statutory provisions[50]. Reconciling conflicting provisions will often require the court "to determine which is the leading provision and which the subordinate provision, and which must give way to the other"[51]. Only by determining the hierarchy of the provisions will it be possible in many cases to give each provision the meaning which best gives effect to its purpose and language while maintaining the unity of the statutory scheme.

…

78. However, the duty of a court is to give the words of a statutory provision the meaning that the legislature is taken to have intended them to have. Ordinarily, that meaning (the legal meaning) will correspond with the grammatical meaning of the provision. But not always. The context of the words, the consequences of a literal or grammatical construction, the purpose of the statute or the canons of construction[56] may require the words of a legislative provision to be read in a way that does not correspond with the literal or grammatical meaning. In Statutory Interpretation, Mr Francis Bennion points out[57]:

"The distinction between literal and legal meaning lies at the heart of the problem of statutory interpretation. An enactment consists of a verbal formula. Unless defectively worded, this has a grammatical meaning in itself. The unwary reader of this formula (particularly if not a lawyer) may mistakenly conclude that the grammatical meaning is all that is of concern. If that were right, there would be little need for books on statutory interpretation. Indeed, so far as concerns law embodied in statute, there would scarcely be a need for law books of any kind. Unhappily this state of being able to rely on grammatical meaning does not prevail in the realm of statute law; nor is it likely to. In some cases the grammatical meaning, when applied to the facts of the instant case, is ambiguous. Furthermore there needs to be brought to the grammatical meaning of an enactment due consideration of the relevant matters drawn from the context (using that term in its widest sense). Consideration of the enactment in its context may raise factors that pull in different ways. For example the desirability of applying the clear literal meaning may conflict with the fact that this does not remedy the mischief that Parliament intended to deal with." (footnotes omitted)

51      Furthermore, as referred to by counsel for WorkSafe, it is open to the Tribunal to be assisted by the evidence of experts in relation to the meaning and effect of technical words and phrases within a specialist body of knowledge. In this respect, reference was made to the decision of the Full Court of the Supreme Court of Western Australia in Re Dr Ken Michael AM; Ex parte Epic Energy (WA) Nominees Pty Ltd & Anor [2002] WASCA 231, per Parker J (Malcolm CJ and Anderson J agreeing) at pars 100 to 107.

52      I adopt these general approaches to the interpretation of the OSH Act, the Regulations, and the terms of the relevant Standards, brought into the statutory regime in the manner outlined above.

Meaning of “boiler”

53      Both Mr Mika and Mr Rajah agreed after conferring, that a “holistic” approach to the definition of “boiler” should be adopted. In Reg 4.1 - Terms used, “boiler” is defined as follows:

 boiler means a vessel or an arrangement of vessels and their interconnecting parts in which steam or other vapour is generated or in which water or other liquid is heated at a pressure above that of the atmosphere by the application of fire, the products of combustion, electrical power or by similar high temperature means and —

 (a) includes superheaters, reheaters, economisers, boiler piping, supports, mounting valves, gauges, fittings, controls, the boiler setting and other equipment directly associated with the boiler;

 (b) does not include a fully flooded or pressurised system where water or other liquid is heated to a temperature lower than the normal atmospheric boiling temperature of the liquid;

54      The general measure of atmospheric pressure, expressed as “ambient” or “standard” atmospheric pressure, is measured at 100 kPa (See McNaught A.D. and Wilkinson A. IUPAC Compendium of Chemical Technology 2nd Edition Oxford 1997).

55      AS 1228-2006 is the principal Australian Standard specifically applicable to pressure equipment designated as boilers. As agreed by the experts, and being specific, the general Standard in relation to pressure vessels, AS 1210-2010, did not strictly apply. This is because the definition of “pressure vessel” excludes a boiler in both Reg 4.1 of the Regulations and in AS 1210-2010. To avoid confusion, it should be one or the other. The purpose and scope of AS 1228-2006 is set out in s 1.1 and is to provide for materials, design, construction, inspection and operation requirements for boilers as defined in AS/NZS 1200:2000. For these purposes, a “boiler” in Appendix E – Definitions in AS/NZS 1200:2000 is as follows:

E2.2 Boiler – a vessel or an arrangement of vessels and interconnecting parts, wherein steam or other vapour is generated, or water or other liquid is heated at a pressure above that of the atmosphere by the application of fire, the products of combustion, electrical power, or similar high temperature means. It also includes superheaters, reheaters, economizers, boiler piping, supports, mountings, valves, gauges, fittings, controls, the boiler setting and directly associated equipment. It does not include a fully flooded or pressurized system where water or other liquid is heated to a temperature lower than the normal atmospheric boiling temperature of the liquid.

56      Plainly, as with the definition of boiler in Reg 4.1, the gas side chambers are not parts of the Units “where steam or other vapour is generated, or water or other liquid is heated at pressure above that of the atmosphere by the application of fire, the products of combustion, electrical power, or similar high temperature means.” In my opinion, this first part of the definition above and in Reg 4.1, is clearly intended to capture the “boiler proper”. By that I mean the contained part(s) of the boiler within the drum or main shell which, by application of high temperature and pressure, steam or vapour is generated or water or other liquid is heated. This is clear from the ordinary and natural meaning of the words used.  If this were not so, it would be unnecessary to include the extended meanings in the next sentence of the above definition, and the extended, inclusive meaning, in Reg 4.1.

57      Following the discussion between Mr Mika and Mr Rajah, Mr Mika now accepts that the gas side chambers can be regarded as part of the extended definition of a boiler, as being a part of the “boiler setting”.  A “boiler setting” is referred to in s 3.13 of AS 1228-2006. Whilst this does not define a “boiler setting” it is expressed in the following terms:

3.13 BOILER SETTINGS

The setting of each boiler shall comply with AS 3892.

Casing construction shall be applied for those parts of the boiler combustion chamber and gas passes which are not completely protected by finned tubes, tangent tubes, or by equivalent tube construction.

Each such combustion setting shall be designed to withstand the maximum positive or negative pressures which it may be subjected to in operation but in no case less than 2 kPa, and, where required, shall be stiffened with buck-stays calculated in accordance with AS 3990.

NOTE: In the design of the casing, consideration should be given to the negative furnace pressures or the combination of casing strength. The boiler/draught controls should be such as to limit the excursions to values which the casing can withstand.

58      It was common ground also that in the last 30 or 40 years, the design and technology used in boilers has changed markedly. A necessary consequence of this fact is whether the regulatory regime for the safe design, fabrication and operation of boilers has kept pace with these changes. It is this very issue which is thrown up by this case. I say that because it was acknowledged by Mr Rajah that the application of the Regulations to boilers of 30 or 40 years ago, was much more straightforward. Necessarily too, as a regulator, WorkSafe has adopted a consistent and conservative view of the application of the Regulations and has been constrained by their terms, in their current form, despite the changes to boiler technology and design, which has occurred over several decades. In this case, the Units are of a different and more recent design, intended to recycle and use exhaust gases that would otherwise be vented to the atmosphere. Accordingly, in this case, WorkSafe looks to the Tribunal to interpret the relevant provisions of the Standards and the Regulations, that are applicable, both for this case, and for similar cases in the future.

Meaning of “pressure parts”

59      Turning to the central question to be answered. It is to be accepted, based on Mr Mika’s evidence, that the design pressure of 37kPa for the gas side chambers is very low. Mr Mika likened the flow of exhaust gases from the engine through the inlet into the gas side chambers and out through the outlet, as loosely analogous to the exhaust pipe of a car. The design pressure is well below standard or ambient atmospheric temperature. As noted earlier, the definitions set out in AS 4942-2001 extend to AS 1228-2006. In AS 4942-2001, “pressure parts” is defined to mean:

“The pressure retaining parts of pressure equipment, e.g. boiler drums, vessels, headers and pipes”

60      AS/NZS 1200:2000 is the “parent” Standard for pressure equipment. In the preface to AS/NZS 1200:2000, the objective of the Standard, as set out on p 3 is to:

(i) clarify overall requirements for pressure equipment used in Australia and New Zealand;

(ii) identify sound economic means of helping to satisfy safety, contract, trade and other relevant laws;

(iii) provide a standard system which recognizes local and international good practices, is mutually acceptable to Australia and New Zealand and is compatible with recognized world Standards; and

(iv) not override regulations or legislation.

61      As the parent Standard, AS/NZS 1200:2000 incorporates by reference, a number of other Standards, set out in Table 2.1 on p 10. Most relevant for present purposes, is that applicable to the construction and design of boilers and pressure vessels in AS 1228-2006 and AS 1210-2010 respectively. I note in passing, that Table 2.1 in relation to “Boilers – General”, refers to ASME BPV-1 the boiler and vessel code applicable in the United States, and which is referenced extensively throughout the Australian Standards documents concerning boilers and pressure vessels. A copy of the most recent ASME Code was annexure WJM2A to the affidavit of Mr Mika dated 16 February 2017. I will return to this later in these reasons.

62      In its scope, AS/NZS 1200:2000 provides at s 1.3 as follows:

1.3 APPLICATION   This Standard is intended to apply to the pressure equipment specified in Appendix A. However, where appropriate and by agreement between the parties concerned, this Standard and its referenced Standards may also be used for all or part of the pressure equipment in Paragraph A3 or for other equipment or plant under pressure.

Equipment with hazard level E to AS 4343 may be covered by one or more of the following methods:

(a) Standards referenced in this Standard.

(b) Other applicable Standards.

(c) Sound engineering practice which achieves a comparable level of safety.

(My emphasis)

63      AS 4343-2005 has as its scope, to determine the hazard level of various kinds of pressure equipment to which AS/NZS 1200:2000 has application.  By s 2.2.2 and Table 1, the “hazard level” for pressure equipment is described as “the potential for harm arising from deficiencies in the design, manufacture and use of pressure equipment and related to the consequences of equipment failure”. Factors are then identified, a very important one, emphasised in the foreword to AS 4343-2005, is the combined effect of pressure and volume. Table 1 then sets out the hazard levels of types of equipment, including boilers. “Pressure” for the purposes of AS 4343-2005, is design pressure and not working pressure. The lowest level of design pressure for the purposes of hazard level assessment, is set at 50kPa. This exceeds the design pressure of the gas side chambers of the Units.  At s 2.1.2, hazard level examples are set out, with level A (high hazard) for large vessels with very high design pressure, to the lowest level E, (negligible hazard) for all those described as “negligible – hazard pressure equipment not classified in hazard levels A, B, C and D”.

64      As sealed units, that is the “pressure envelope” proper is sealed by tube plates at either end, the gas side chambers are described by ECI as having category E level of hazard, with a design pressure maximum of 37kPa. This hazard level was not in contest in these proceedings. While the definition of “pressure vessel” in Reg 4.1 of the Regulations does not specify any design pressure, even if one was to look to AS 1210-2010 as a guide, as will be seen below, it has a lower level design pressure, below which the Standard does not apply. Any such “pressure vessel”, not caught by a Standard, is to be designed in accordance with “sound engineering practice which achieves a comparable level of safety”: AS/NZS 1200:2000 s 1.3(c), set out above.

65      Relevantly also for present purposes, is s 2.3 of AS/NZS 1200:2000.  It provides as follows:

2.3 MIXING STANDARDS     Pressure equipment shall comply with the full requirements of a Standard, except when the equipment or parts of the equipment comply with the more appropriate requirements of other pressure equipment Standards provided -

(a) such Standards comply with an agreed alternative or equivalent and are applicable to the particular pressure equipment;

(b) the relevant requirements of the Standards apply to the parts concerned;

(c) at the interfaces between the parts with different Standards, the parts comply with both Standards as appropriate;

(d) the design data, drawings and manufacturer's data report clearly identify and record departures from the principal Standard;

(e) the equipment marking includes the two main Standards used;

(f) the overall equipment complies with Clause 2.1; and

(g) the parties concerned, including the design verification and fabrication inspection bodies, agree.

NOTES: 

1 Typical examples are the use of pressure vessel or piping Standards for some parts of boilers, the use of other Standards for materials, components, qualification and test methods, use of piping Standards for some pressure vessels (e.g. piping strainers), and different documentation markings.

2 Some Standards already permit alternative referenced Standards.

(My emphasis)

66      In this case, the approach adopted by ECI, as set out in Mr Mika’s evidence, is essentially an example of this, where different Standards were applied to some parts of the “boiler”. I see no inherent difficulty in this.

67      In AS 1228-2006, in relation to the steel plate issue, the crucial part of the Standard is in s 2 – Materials and Design Strengths. By s 2.1.1 – General, it is provided that “materials used in the construction of pressure parts of boilers shall comply with the appropriate specifications or requirements listed in Table 2.1 or Clauses 2.1.5, 2.1.6 and 2.1.7 and shall be identified in accordance with Clause 2.1.2”. By s 2.1.6 – Use of structural or similar quality steels, structural steel not referred to in Table 2.1, may be used for “pressure parts” if a number of conditions are met, one of which is the design temperature is not greater than 250°C.

68      Correspondingly, in Table 2.2.1, dealing with design strength values, the reference to AS/NZS 3678-250 steel (the grade used in the shell of the Units) is listed as having no design strength values beyond 250°C. Therefore, all other things being equal, taking Table 2.2.1 and the notations at the foot of the table, read with s 2.1.6, leads to the conclusion that AS/NZS 3678-250 steel should not be used for pressure parts (as defined), exposed to a design temperature greater than 350°C, in circumstances where AS 1228-2006 applies. Thus, the position as adopted by WorkSafe in these proceedings.

69      As already noted, Mr Mika has now accepted in his evidence that the gas side chambers, adopting a holistic view of a boiler, can now be regarded as part of the “boiler setting” in the extended definition of boiler in Reg 4.1. The effect of this, along with the inclusion of the definition of “pressure equipment” in Reg 4.1, is to require the relevant plant as specified in Schedule 4.1 (and as defined in Reg 4.1) to have design and plant registration in place. The reason for this is obvious. The items of plant covered by Part 4 of the Regulations may be hazardous and may carry a risk of injury to persons, in the design, manufacture, installation and use of such plant.

70      I am satisfied on the evidence that ECI’s concession in relation to the gas side chambers as being part of the “boiler setting” for the purposes of the general definition of boiler in Reg 4.1 of the Regulations, is properly made. However, simply because the gas side chambers of the Units may be included in the scope of the extended definition of a boiler under the Regulations, does not provide the answer to the issue to be determined in this case. This is because the ultimate question to be determined is whether, accepting that the Units are covered by the terms of Part 4 of the Regulations, the design and manufacture of the Units was in accordance with the relevant Australian Standards, as specified in Sch 4.3. This is picked up principally by the obligation on a design verifier to certify under Reg 4.3(2), that the plant design complies with the relevant Australian Standard as set out in Sch 4.3.

71      It is accepted by WorkSafe that the gas side chambers are not “interconnecting parts” for the purposes of the definition of a boiler. As noted above, it is also plainly the case and it was not contended to the contrary, that the gas side chambers are not components in which steam or other vapour is generated. That is, in my view, it must be concluded that the gas side chambers are not part of the sealed “pressure envelope”, or the “boiler proper”, in which the steam or vapour is generated in the Units, arising from the exhaust gases in the tubes heating the water to boiling point, from which steam is extracted through the steam outlet, as shown in the Unit diagram in annexure 1 to these reasons.

72      As to what is or is not a “pressure part”, in the proceedings, and in response to questions from the Tribunal, Mr Rennie expressed the view that it could conceivably apply to any part or component which contains any level of pressure at all, at or beyond atmospheric pressure. Mr Rennie expressed the view that the fluorescent tube above the Bench in the court room which I sat, could be described as a vessel containing pressure. If so, and if applicable to a boiler, then applying this logic, it would be so characterised as a “pressure part”.

73      As with any interpretive process, the provisions of the Standards the subject of consideration in these proceedings, need to be considered consistent with their scope, purposes and context.  One part or parts of a Standard cannot be viewed in isolation from the whole. There are many Australian Standards relevant to pressure equipment generally, most, if not all of them, are contained in the materials before the Tribunal. I have examined all of them. In my view, they should be construed consistently as part of an overall scheme for the design, manufacture, operation and maintenance of pressure equipment.

74      I have set out s 1.3 of AS/NZS 1200:2000 above. From the first paragraph, it is clear in my view that the “parent” Standard for pressure vessels in Australia, is principally concerned with the design and operation etc of “equipment or plant under pressure”. Additionally, Appendix A of AS/NZS 1200:2000 lists the “pressure equipment covered” in the Standard, and, in addition to boilers, pressure vessels and pressure piping, contains a list of “equipment or plant under pressure not specifically covered”. There follows a list of equipment and plant all of which in common parlance, would be understood to operate at very considerable pressure, certainly considerably greater than at or just above atmospheric pressure. (My emphasis)

75      It is also clear from the terms of AS 4343-2005 itself and at pp 7 to 9, that the Standards in relation to pressure vessels, and specifically AS 1210-2010, are designed to keep the risk of hazards as low as reasonably practicable, with the aim of a very low probability of failure.

76      Returning then to AS 4942-2001 and the definition of “pressure part”. This definition, as with the definitions in the Standard, are intended to apply across the range of Standards in relation to pressure equipment generally, including boilers. These general definitions however, consistent with usual interpretive principles, would be subject to any specific definition in another Standard. In accordance with the scheme to which I have referred, I do not consider that “pressure part” means any part of a boiler or pressure vessel, that has any level of pressure, at for example, atmospheric pressure. The examples given in the definition itself, such as “boiler drums”, “vessels”, are clear indications that the definition refers to a part under substantial pressure, whether it be in the water/steam envelope or in some other part of a boiler or pressure vessel. Other parts given in the definition include “headers” and “pipes”. A “header” is also defined in AS 4942-2001 to mean “a pressure part whose principal purpose is to collect fluid from, or distribute fluid to, arrays of tubes or pipes directly connected to it”. The header of a boiler will most often operate under very substantial pressure.   

77      Additionally, the definitions in AS 1228-2006 itself at s 1.3, refer to types of boilers, “design pressure”, “drum”, “header”, “tubular pressure part”, “integral piping”, “tube” and other elements or key components of boilers, that plainly operate under substantial pressure. The reference to “calculation pressure” for all pressure parts in s 1.3.2 of AS 1228-2006, in item (a), refers to “design pressure increased…corresponding to the most severe conditions of operation”. In item (b), reference is made to calculations for “boiler pressure components” (a new term) based on measurements “at the steam outlet…corresponding to the most severe conditions of operation”. When read as a whole, these definitions tend to support the proposition that the principal focus and tenor of the Standard is directed to the high pressure components of boilers, in terms of their safe design, manufacture, maintenance and use. 

78      Furthermore, a “vessel” is not defined in either the Regulations or the Standards.  The most common reference in the Standards is to “pressure vessel”. In these circumstances, the ordinary definition may assist. In the Shorter Oxford English Dictionary “Vessel” is defined to mean “2. A receptacle for a liquid or other substance, often one of circular section and made of some durable material…” Similarly, the Macquarie Dictionary defines a “vessel” as “2. a hollow or concave article, as a cup, bowl, pot, pitcher, vase, bottle etc., for holding liquid or other contents…” Are the gas side chambers, vessels ordinarily understood? They do not hold or retain any gas or liquid. They constitute chambers or passages through which heated exhaust gases enter and exit the Units. I very much doubt that they are vessels in the ordinary sense of the word. They are obviously not headers or pipes.

79      In my view, when considered in the context of the totality of the pressure vessel Standards and not in isolation, and the various definitions to which I have referred, the gas side chambers of the Units, which are accepted to fall below the minimum or negligible hazard level for design pressure as specified in AS 1210-2010, even using this Standard as a form of guide, should not be construed as “pressure parts” for the purposes of AS 4942-2001 and AS 1228-2006. I note also that whilst not in any way determinative, this conclusion appears consistent with the views expressed by Mr Ford of PB, in his independent assessment of the issues in dispute between the parties, as annexed to Mr Rajah’s witness statement at R5 p 10.

80      I therefore do not consider that the terms of s 2.1.1 or 2.1.6 of AS 1228-2006 have application to the gas side chambers of the Units, in accordance with the altered design. I consider that construed in its total context, the terms of AS 1228-2006 in relation to “pressure parts”, is intended to capture the “boiler proper”, i.e. the water/steam envelope and those other parts of a boiler designed to retain a significant pressure, certainly substantially greater than 37kPa, the maximum design pressure for the gas side chambers of the Units.

Sound engineering practice

81      Having reached this conclusion, it is next necessary for the Tribunal to consider the approach to adopt to the design process, based upon the materials and evidence before it. The HRL report (annexure R6.1 to Mr Rajah’s witness statement) concluded that with the design alteration to the gas side chambers, the terms of AS 1210-2010 were not applicable. This was not challenged on the evidence, even if AS 1210-2010 could be viewed as a guide. However, HRL then considered the appropriate approach to adopt based on “good engineering practice”, in assessing the use of AS/NZS 3678-250 steel plates, by adopting the design rules for pressure equipment. HRL then performed their calculations accordingly, as set out in its report. Using an extrapolation technique, HRL considered the design strength to be adequate.

82      The HRL report design strength calculations were the subject of further review and analysis by Mr Mika in February 2017, and recorded in a further technical note, a copy of which was annexure WJM3A to Mr Mika’s affidavit of 16 February 2017. The technical note, whilst not expressing it as such, was presumably prepared in response to observations made by Mr Rajah at par 29 of his witness statement of 9 January 2017, where he expressed the view that the HRL calculations were not prudent engineering practice, because of the use of extrapolation of data and not the use of linear interpolation.

83      Mr Mika in his technical note, examined the HRL methodology and also considered other sources of data in relation to the design strength of structural steel at temperatures in excess of 350°C. Specifically, reference is made to AS 4100-1998 for structural design and the use of structural steel at high temperatures, in excess of 800°C. Mr Mika notes that the qualification to AS 4100-1998, is that it may not adequately deal with the heating of structural steel for extended periods of time, and further notes the possibility of “creep”, which may be defined as the “slow and continuous deformation of a metal at high temperatures”.  Given that the gas side chambers would, under normal operating conditions, operate at high temperatures for extended periods of time, it was necessary to examine this by comparing similar grades of steel under creep conditions, as data was not available for AS/NZS 3678-250 structural steel, as such tests are not required for this grade of steel.

84      Mr Mika noted HRL’s extensive experience (50 plus years) in the design, integrity assessment and life assessment of boilers for use in steam generation both in Australia and overseas. He further noted their access to test data, both published and proprietary, from their own work. Mr Mika undertook further analysis of the design data and the conclusions reached by HRL, based on a report prepared by the Electric Power Research Institute in March 2007, on the use of carbon steels at elevated temperatures.  Mr Mika calculated design strength curves for the EPRI, HRL and normalised them to the AS 4100-1998 data, in diagram form. Mr Mika concluded from this analysis, that the HRL curve was below the AS 4100-1998 curve, without creep and the EPRI curve, with creep. He concluded from this analysis, that the HRL approach and conclusions were both conservative and consistent with reasonable and prudent practice.

85      The Tribunal also notes that the PB report at pp 15-16 discussed the issue of the maximum design temperature for the boiler shell. In considering the shell extensions, which constitute the gas side chambers, reference is made by PB to the issue of possible differential expansion between the uncooled shell extensions and the cooled shell and tube plates.  In recognition of this, it was recommended by PB that there be an enhanced inspection regime introduced to monitor this issue. The Tribunal considers this recommendation to be prudent. It is suggested that the parties confer in relation to an enhanced inspection regime.

86      Having considered the evidence and material before it carefully, the Tribunal’s conclusion is that the design alteration in relation to the gas side chambers of the Units, is consistent with “sound engineering practice which achieves a comparable level of safety”, for the purposes of s 1.3 of AS/NZS 1200:2000. Mr Mika emphatically stated in his evidence before the Tribunal that in adopting the revised design approach, the Units were safe. The Tribunal is satisfied that the design alteration, while accepting the criticism advanced by WorkSafe in relation to the BV design verification process, is in overall terms, compliant with Schedule 4.3 of the Regulations, and is plant for the purposes of Part 4 of the Regulations which is safe in terms of the requirements of ss 5 and 23 of the OSH Act.

87      Having considered the above issues, it is now necessary for the Tribunal to comment on the various exemption requests.

Exemptions

88      In addition to the evidence led before the Tribunal, materials in relation to the various exemption requests made by ECI were set out at annexures R7.1 to R7. 4 of Mr Rajah’s witness statement. Additionally, was the exemption request made by Brookfield Multiplex FSH Contractor Pty Ltd at annexure R7.5.

89      As to the issue of the inspection openings not being compliant with s 3.9.5 of AS 1228-2006, for the reasons identified above, an exemption under Reg 2.13 should be granted. It would clearly be impracticable to now require compliance, in circumstances where readily available and commonly used alternative remote inspection technology will achieve the same result. In any event, it appears that the use of remote viewing systems may even be more effective than a visual inspection of the Units alone.

90      The next matter of the non-destructive testing of the welds on the shells of the Units, has also been commented on by the Tribunal on the evidence. Subject to the agreed position of the parties, and the process for the ultrasonic testing of the welds to take place, this exemption should be granted.

91      A further issue arises in relation to the boiler tube thickness. This was not a matter raised in the WorkSafe letter of 5 September 2016, setting out the reasons for the decision to deregister the plant designs for the Units. It was however, raised as a matter of concern by Mr Rajah on his evidence before the Tribunal.  It was also the subject of some discussion by the experts in the concurrent evidence session. Sections 3.7.1 and 3.7.2 of AS 1228-2006 prescribe the minimum nominal thickness of tubes and pipes of boilers subject to internal and external pressure.

92      In his evidence, Mr Rajah noted that based on AS 1228-2006, the tube thickness should be 2.81mm and not 2.41mm, as is the design thickness of the tubes. This is despite BV endorsing both the original and older design as being in accordance with Table 3.7.1 of AS 1228-2006, which Mr Mika conceded in his evidence, was not correct.  Mr Mika addressed this matter in his evidence.  He accepted the design thickness of the tubes of 2.41mm does not comply with the requirements of AS 1228-2006.

93      In responding to this issue, Mr Mika testified that a comparable standard to use to assess the appropriateness of the tube thickness is the ASME Code 2013, referred to above. This is a comparable standard to AS 1228-2006 which applies in the United States and prescribes rules for the construction of boilers. The relevant provision of the ASME Code is PG – 28.3 – Maximum Allowable External Working Pressure for Cylindrical Components. Part PG of the ASME Code applies to “power boilers and high pressure, high-temperature water boilers and to parts and appurtenances thereto…”

94      The ASME Code is extensively referred to in both AS 1228-2006 and AS 1210-2010 and is cited as an alternative acceptable Standard for compliance in appropriate cases. That the ASME Code is specifically referred to in the Preface on p 2 of AS 1228-2006 in relation to design strength values in Table 2.2.1 and that those values have been “revised and updated to fall into line with the latest editions of the AS (e.g. AS 1548), BS and ASME material specifications and standards …” is a very clear indication of the standing of the ASME Code and its predecessors. There was no serious suggestion to the contrary advanced by WorkSafe.

95      Mr Mika’s technical note in relation to the tube thickness issue is at annexure WJM3AA to his affidavit of 27 February 2017. The technical note contains a careful and detailed calculation of design thickness of components under pressure, based on PG - 28.3 of the ASME Code. Mr Mika concluded that on both the boiler side and the gas side, the thickness of the tubes in the Units would fall well within the margin for design thickness of cylindrical components under pressure. There was no challenge to this evidence and the Tribunal accepts it.

96      The final matter upon which comment is needed, relates to the exemption request in relation to the omission of two rows of unwelded plain tubes at each end of the Units, in accordance with AS 2593-2004. The basis for the exemption request was set out in the ECI application for exemption dated 5 April 2016, contained at annexure R7.4 to Mr Rajah’s witness statement.  ECI maintained that compliance with this requirement was both unnecessary and impractical. The supporting material sets out the reasons why ECI maintained that the two rows of plain tubes were unnecessary. First, the Units do not contain furnace tubes. Second, the apparent but unstated intention of AS 2593-2004, is to provide a form of protection to the furnace tube in the case of an excursion, resulting in the overheating of the furnace tube area. Third, the exemption refers to controls in two respects, they being the specification of the operating envelope of the Units and the use of insulation material on the gas side of the tube sheets. This shields the areas of the tube sheets above the operating water level from contact with the flue gas.

97      ECI also referred to the operation of the control system to provide isolation of the heat source from the boiler, if the situation arose where either the water or gas side of the Units exceeded its operational parameters.  In this respect, annexed to the same application for exemption by Brookfield Multiplex, at annexure R7.5, is a report prepared by RCR Energy Service, verifying the settings on the Unit controls for alarms, trips and for pressure relief.

98      Having considered this material, and there being no opposition expressed by WorkSafe to the exemption request, the Tribunal considers it should be granted also.

Restriction on design use

99      The Tribunal should finally note that it was advanced as a concession by ECI, that should the Tribunal find that the application to review be upheld, then it agrees that the design for the Units be confined to the two installed at Fiona Stanley Hospital. The design will not be able to be used for the manufacture of further waste heat units, in Western Australia or elsewhere.

Conclusions

100   In this matter, the Tribunal has concluded that the Units fall within the extended definition of a “boiler” for the purposes of Reg 4.1 of the Regulations, as part of the boiler setting. Having regard for the terms of the relevant Australian Standards, the Tribunal has concluded that the altered design for the Units, in relation to the gas side chambers, meets the requirements of those Standards for the purposes of registration under Part 4 of the Regulations, as being based on sound engineering practice that achieves a comparable level of safety. The design, as altered, in accordance with the concession made by ECI, is limited to the Units at Fiona Stanley Hospital in Perth, and may not be used for any other fabrication. The parties have also been requested to confer as to an enhanced regime of inspection for the Unit shells, in accordance with the recommendation made in the PB report of 13 May 2015.

101   Consistent with the position as agreed between the parties, the Tribunal has also considered the various exemption requests made by ECI. The Tribunal has determined that these requests should be granted by WorkSafe. Accordingly, for the foregoing reasons, the application to review is upheld. The parties are requested to confer within 14 days as to a draft order giving effect to these reasons for decision, consistent with s 61A(3) of the OSH Act and the scope of orders the legislature has empowered the Tribunal to make.

102   Finally, the Tribunal wishes to record its appreciation for the assistance provided by the experts, Mr Rajah and Mr Mika and counsel for the parties, in the course of the proceedings.

Annexure 1