Question 1

What equipment requires design verification?

Accepted Answer

Pressure equipment which contains:
-  Gases at pressure exceeding 50 kPag
-  Liquids at pressures exceeding 50 kPag
or
-  Steam

Pressure equipment includes boiler, boiler piping, compressor, fired heater, gas turbine, hot water boiler, piping component, pressure fittings, pressure piping, pressure vessel, pump, steam engine, or steam turbine

Cranes
All powered cranes, including those attached to a vehicle and used for loading and unloading that vehicle.

Passenger Ropeways
a cableway or ropeway used for conveying in a horizontal or inclined plane person who are on skis, supported by chairs, or in enclosed cars.

refer also:
https://www.worksafe.govt.nz/dmsdocument/419-health-and-safety-in-employment-pressure-equipment-cranes-and-passenger-ropeways-regulations-1999 (https://www.worksafe.govt.nz/dmsdocument/419-health-and-safety-in-employment-pressure-equipment-cranes-and-passenger-ropeways-regulations-1999)

Question 2

What is Design Verification?

Accepted Answer

Design verification is a comprehensive review of the design of an item of equipment based on detailed fabrication or manufacturing drawings. If the design is approved a design verification certificate is issued and the equipment drawings are stamped by the design verifier.

from AS3920, design verification is a documented comprehensive examination and review of a design to evaluate its conformance with specified requirements, and identify any perceived deficiencies.

The purpose of design verification is to provide suitable and sufficient checking of the design drawings and other nomination documents to:
(a) identify and significant errors or omissions;
(b) confirm that the design conforms with good engineering principles; and
(c) give a high degree of confidence that the design of pressure equipment is safe and complies with the design standard, applicable laws and the stated purchaser requirements.

from NZ's PECPR regulations
design verification means verification that the following comply, in every respect related to safety, with the requirements of the appropriate design standards and contain every safety feature that is relevant, whether or not referred to in those standards:
(a)
designs of equipment, and
(b)
alterations to designs, affecting the structural strength or safety of equipment, made in the course of manufacture; and
(c)
designs of a repair or alteration affecting the operational safety of the equipment repaired or altered or any other equipment; and
(d)
the fabrication inspection requirements specified by the designer

Question 3

Is design registration or plant registration required in NZ ?

Accepted Answer

Unlike in Australia, WorkSafe NZ does not maintain a register of pressure equipment designs or pressure equipment items. Each body which issues design verification certificates maintains it’s own register.

The inspection body which performs the site inspection once the equipment is installed, issues the certificate of inspection (or operating certificate) and assigns a “Unique Number” to each equipment item.

Each inspection body maintains its own register equipment identification numbers ("Unique Number").

Question 4

Is design verification required for piping NZ ?

Accepted Answer

Yes

We are not aware of any other jurisdiction which requires design verification of piping in the same manner as in NZ (for general pressure piping). This typically involves piping stress analysis being performed using a software program like AutoPIPE.

Because overseas inspection bodies are unlikely to have experience performing design verification of  pressure piping in this manner, we recommend engaging a NZ based design verifier to provide this service.

Question 5

Who can perform design verification?

Accepted Answer

The body which issues the design verification certificate must first be recognised (approved) by Work Safe NZ.

A register of approved organisations is available at:
https://www.worksafe.govt.nz/the-toolshed/registers/recognised-inspection-bodies/ (https://www.worksafe.govt.nz/the-toolshed/registers/recognised-inspection-bodies/)

One such organisation is Rhodes Engineering and Design Limited (www.rhodeseng.co.nz)(http://www.rhodeseng.co.nz/)

For pressure equipment design verification requirements depend on Hazard Level determined in accordance with standard AS4343.

Hazard level A,B,C and D pressure equipment (including piping) requires design verification by an organisation approved by WorkSafe NZ.

In-house design verification may be performed for hazard level C and D equipment if the organisation is first approved by WorkSafe NZ (approval is detailed in a "letter of exemption"). Further details are contained in Appendix A of the Appproved Code of Practice for Pressure Equipment (ACOP), https://www.worksafe.govt.nz/assets/dmsassets/zero/2WKS-1-boilers-acop-pressure-equipment.pdf (https://www.worksafe.govt.nz/assets/dmsassets/zero/2WKS-1-boilers-acop-pressure-equipment.pdf)

Question 6

Our equipment design is commercially sensitive so we cannot supply manufacturing drawings, can we obtain design verification?

Accepted Answer

No, not without supplying detailed drawings for review.

You can rest assured that confidentiality of information supplied for design verification will be respected:
- For NZ Chartered Professional Engineers, confidentiality of client information is mandated legally under "Chartered Professional Engineers of New Zealand Rules (No 2) 2002" coming into force under the "Chartered Professional Engineers of New Zealand Act 2002"
- ISO17020 Inspection Bodies, are required to have legally enforceable commitments to respecting confidentiality of client information
- We recommend you ask the design verifier to supply their organisations confidentiality policy for your review.

It is the pressure retaining shell and structure which are of interest for design verification. In general, we find that for pressure vessels these components do not contain any significant unique features, and are generally based on designs which are in the public domain, many decades old, and available in handbooks such as Moss, Pressure Vessel Design Manual. Many details, such as nozzle welds, must meet prescriptive code requirements (and match figures in the design code) so can not possibly contain any unique intellectual property.

The details required for design verification, such as wall thicknesses and dimensions of members, are also readily available to the end user by measuring the supplied piece of equipment.

Even for composite pressure vessels, we find details required such as lay-up and material specifications, are generally readily available from material suppliers, and are generally similar-to those in published papers for design of composite pressure equipment.

Details of proprietary internal components, if they do not affect the structural integrity of the equipment, do not generally need to be supplied

Just fundamental details such as overall dimensions and mass, details of supports for vessel internals, which are welded to the vessel shell, will be required for design verification.

Question 7

What is considered in design verification?

Accepted Answer

Extent of design verification (for NZ), for pressure equipment is outlined in the ACOPs:

https://www.worksafe.govt.nz/assets/dmsassets/zero/2WKS-1-boilers-acop-pressure-equipment.pdf (https://www.worksafe.govt.nz/assets/dmsassets/zero/2WKS-1-boilers-acop-pressure-equipment.pdf)

https://worksafe.govt.nz/dmsdocument/1571-acop-the-design-safe-operation-maintenance-and-service-of-boilers (https://worksafe.govt.nz/dmsdocument/1571-acop-the-design-safe-operation-maintenance-and-service-of-boilers)

This includes:
(a) Suitability of materials for service
(b) Adequacy of all pressure parts for design operating conditions including the effect of pressure, temperature, externally applied loads and local environmental conditions such as seismic disturbances and wind, snow and ice
(c) Manufacturing and testing requirements including the inspection and test plan;
(d) Specifications for flanges, valves and fittings 
(e) Transportation and erection plans and procedures 
(f) Equipment design life including the procedure to be followed when the end of any finite life is reached;
(g) Equipment supports not covered by CPEng certificates (typically supporting structure not welded to equipment and foundations) 
and 
(h) Where appropriate any other aspects of design affecting safety.

Per the regulations (PECPR), design and design verification must take into account the nature of the New Zealand seismic environment.

Question 8

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Accepted Answer

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