Designing Electrolyte Filters to AS 1210: What an Australian Tankhouse Spec Actually Requires

Short answer: a pressure leaf or precoat filter is a pressure vessel, so in Australia it falls under
AS 1210, the design code of record, sitting beneath the parent standard AS/NZS 1200. Before anyone cuts
plate, the vessel has to be hazard-classified to AS 4343, and in Western Australia a hazard level of A,
B, C or D means the design must be registered before manufacture. Levels A, B and C also need item
registration once installed. If you are importing a filter built to ASME VIII, that is allowed, but it
is not free: the hydrotest, the nozzle-load method and the allowable stresses are not the same.

Your filter is a pressure vessel, and that changes the paperwork

Engineers specifying electrolyte clarification tend to think about the duty first: flow, solids loading,
cake discharge, DE consumption. All correct, and all beside the point the day the vessel has to be
registered. A pressure leaf filter operates under pressure, which puts it squarely inside Australia's
pressure equipment regime, and that regime has opinions about your project schedule.

The single most expensive thing to learn late is this: design registration happens before manufacture,
not before commissioning. If the design is not registered, the vessel should not be built. Discovering
that after fabrication has started is how a filtration package becomes a critical-path item.

The code stack, in the order it applies to you

Four documents matter, and they do different jobs:

• AS/NZS 1200 is the parent. It sets the general requirements for pressure equipment across design,
  materials, manufacture, examination, testing, installation, conformity assessment, commissioning,
  operation, inspection, maintenance, repair, alteration and disposal. It is the umbrella, not the
  calculation.

• AS 1210 is the design code of record for pressure vessels made or used in Australia. This is where
  the engineering lives: allowable stresses, design equations, fabrication rules for welding, joining
  and forming, marking, hydrostatic and pneumatic testing, and protection devices such as relief valves.
  It offers design-by-rule methods for standard vessels and covers up to roughly 21 MPa depending on
  materials and temperature. A tankhouse filter sits far below that ceiling, which is worth remembering
  when someone treats the code as exotic. It is not. It is routine, and it is mandatory.

• AS 4343 decides how much regulatory burden you carry, by assigning a hazard level.

• AS 3920 covers quality assurance, and tends to surface as an extra compliance item when an
  imported design is being brought into line.

AS 4343: the hazard level sets your burden

AS 4343 classifies pressure equipment into hazard levels against AS/NZS 1200, and it also classifies the
fluid. The logic is refreshingly physical: the basis is the maximum stored energy that could be
released in 5 to 10 seconds, together with the level of exposure. For a vessel, the calculation runs on
pressure and volume. For piping it uses pressure and diameter, in a manner deliberately similar to
the European PED so the numbers are easy to work with.

For a filtration package this has a practical consequence engineers routinely miss. Hazard level is not
a property of what you are filtering alone. It is driven by pressure multiplied by volume, and by the
fluid classification, and by exposure. A large-volume clarification vessel at modest pressure can land in
a higher hazard level than a small vessel at high pressure. Size your vessel, then classify it. Do not
assume the class.

Design registration versus item registration

These are two different things, and conflating them causes real delay. Taking Western Australia, where
the regulator is explicit:

• Design registration is required for hazard levels A, B, C or D, and it must be done before
  manufacture.

• Item registration, meaning the individual piece of plant once it exists, is required for hazard
  levels A, B or C only.

• Hazard level D therefore needs its design registered but not the item.

• Hazard level E needs neither.

• Gas cylinders and serially produced vessels are excluded from item registration.

• Anything outside the scope of AS/NZS 1200 is out of the regime entirely.

Duties fall on designers and manufacturers under the Work Health and Safety Act, and the registration
holder is responsible for keeping the registered information current. In other words this is not solely
the buyer's problem, and a vendor who cannot engage with it is telling you something.

Can you import an ASME VIII filter into Australia?

Yes. ASME VIII Divisions 1, 2 and 3 vessels are acceptable in Australia under AS/NZS 1200, and importing
one is entirely legitimate. Anyone who tells you an ASME vessel cannot be used in Australia is wrong.

What is also true is that it is not a free swap. Design-verification practitioners consistently report
the following differences, and they are the ones that generate rework:

• Hydrotest pressure. AS 1210 calls for 1.5 times design pressure. ASME VIII-1 calls for 1.3
  times MAWP. The eastern states typically expect the AS 1210 figure.

• External nozzle loads. AS 1210 expects PD 5500 Annex G methodology, not WRC 107 or WRC 297.
  If your vendor sized nozzles the American way, that calculation gets redone.

• Allowable stresses. AS 1210 is the more conservative of the two, which can drive thickness.

• Additional compliance with AS 1210, AS 3920 and AS 4343 may be required depending on the level of
  compliance the client wants.

And one that saves money if you catch it early: U-stamping is not mandatory for domestic Australian
installations, whatever ASME code was used. Practitioners are blunt that the stamp is legally
irrelevant in Australia. Procurement documents nonetheless specify it out of habit. If a U-stamp is in
your spec and nobody can say which regulation requires it, that line is costing you money and vendors.

Above all, using ASME does not dissolve the local duties. You still classify to AS 4343 and you still
register. The code choice changes the calculation, not the regime.

Western Australia is the jurisdiction to watch

This is where an Australia-wide assumption gets expensive, and it matters because so much of Australia's
nickel, cobalt and hydromet capacity sits in WA.

Most Australian states will accept design codes published by any recognised standards organisation.
Western Australia is reported by design-verification specialists to be narrower: the design must be to
AS 1210, ASME BPV Code Section VIII Division 1 or 2, or BS 5500. Three codes, and no others.

The trap is subtler than a straight rejection. Practitioners report that WA will recognise a design
registration granted in another state, but will not recognise the plant registration if the design and
fabrication were to any other code. Read that carefully: your vessel can hold a valid design
registration obtained elsewhere and still not be operable as plant in WA. A filter built to a code that
is perfectly acceptable in another state can arrive on a WA site and be unusable.

Because this rule comes from specialist practice rather than a published WorkSafe WA page, confirm it
for your project before you commit. WorkSafe WA publishes a contact address specifically for plant
design questions, and one email is cheaper than a re-design.

What to put in the enquiry

If you are an EPC or an owner's engineer specifying electrolyte clarification for an Australian site,
the filtration vendor needs these to answer properly, and their absence is why quotes come back vague:

• Design pressure and design temperature, and the vessel volume, since these drive the AS 4343 hazard level.

• The fluid and its classification.

• The design code you require: AS 1210, or ASME VIII if the site accepts it. State the state.

• Whether design registration is the vendor's scope or yours, and in which jurisdiction.

• Whether third-party design verification is required, and by whom.

• Materials of construction for the wetted parts, which for acidic copper and nickel electrolyte
  generally means stainless steel.

• Duty data: flow, solids loading, particle size, cycle expectations.

A vendor who answers the duty questions but goes quiet on the code questions has told you which half of
the job they have done before.

Where we sit

We build leaf and precoat filters for electrolyte clarification and hydromet duties: horizontal pressure
leaf with hydraulic closure, vertical pressure leaf with eye-bolt closure, and rotary horizontal precoat.
Capacities run from 5 to 350 m³/hr, and we have designed to AS 1210.

For the rest of the record, plainly: around 1,000 units installed worldwide across 400+ installations,
25 units in copper refining, and repeat orders placed after 20 to 25 years with the original filters
still in service. That supply record is in India, Africa and Europe. We are not going to dress it up as
an Australian track record, because the first thing a competent EPC does is check.

Frequently asked questions

Does a pressure leaf filter need to comply with AS 1210 in Australia?
Yes. A pressure leaf or precoat filter is a pressure vessel, so it falls under Australia's pressure
equipment regime. AS 1210 is the design code of record for pressure vessels manufactured or used in
Australia, sitting under the parent standard AS/NZS 1200. The vessel also needs hazard classification to
AS 4343.

When does a pressure vessel need design registration in Australia?
In Western Australia, design registration is required for hazard levels A, B, C or D under AS 4343:2014,
and it must be completed before manufacture. Item registration, for the individual piece of plant, is
required for hazard levels A, B or C only. Hazard level E requires neither. Requirements vary by state,
so confirm with the relevant regulator.

What is the difference between design registration and item registration?
Design registration approves the design itself and must be in place before the vessel is manufactured.
Item registration applies to the specific manufactured piece of plant once it exists. A hazard level D
vessel needs design registration but not item registration. Gas cylinders and serially produced vessels
are excluded from item registration.

Can I use an ASME VIII pressure vessel in Australia?
Yes. ASME VIII Divisions 1, 2 and 3 are acceptable under AS/NZS 1200. However the hydrotest differs, at
1.5 times design pressure for AS 1210 against 1.3 times MAWP for ASME VIII-1, external nozzle loads are
expected per PD 5500 Annex G rather than WRC 107 or WRC 297, and AS 1210 allowable stresses are more
conservative. You still have to classify and register locally.

Is a U-stamp required in Australia?
No. U-stamping is not mandatory for domestic Australian installations regardless of the ASME code used,
and practitioners describe the stamp as legally irrelevant in Australia. Clients nevertheless still
specify it in procurement documents, so it is worth asking whether your spec actually needs it.

Which design codes does Western Australia accept?
Design-verification specialists report that WA requires design to AS 1210, ASME BPV Code Section VIII
Division 1 or 2, or BS 5500, and that while WA will recognise a design registration from another state,
it will not recognise the plant registration if the design and fabrication were to any other code. Other
states are broader. Confirm your specific case with WorkSafe WA before committing.

One ask

If you are specifying electrolyte or hydromet filtration for an Australian site, send us the design
pressure, temperature, volume, fluid and duty data, and tell us the state and the code you need. We will
come back with the sizing and tell you where the hazard level is likely to land, so the registration
path is visible before it is a schedule problem.