Argon 5.0 in NZ: Purity, Impurities & When It Pays to Go Ultra-High

If you buy argon in New Zealand for welding, labs, or process control, you’ve probably seen grade numbers like 4.6, 4.8 and 5.0. You’ve also felt the pressure to justify higher-purity gas to finance or procurement: is Argon 5.0 (≥99.999%) really worth it over industrial or 4.6 (99.996%)? And when does LAR (liquid argon) beat high-pressure cylinders on cost and logistics?

This article is not a generic “what is argon” explainer. It’s a specification-driven piece built for NZ fabricators, labs and HSE/procurement teams. We’ll map the purity ladder, list ppm impurity limits for Argon 5.0, walk through a chromatography vs TIG decision tree you can defend in an audit, and outline a liquid vs cylinder break-even framework using NZ-specific cylinder capacities and outlet types.

1) Purity ladder: what 4.6, 4.8 and 5.0 actually mean

In specialty gases, the digit after the decimal denotes the number of “nines” in the percentage purity. That is, 4.6 = 99.996%, 4.8 = 99.998%, 5.0 = 99.999%. This convention is widely used by global suppliers and is a reliable way to interpret grade labels across brands.Why you care: the headline purity helps you benchmark background contamination risk for sensitive instrumentation (GC/ICP) and weld quality for high-value materials (e.g., titanium, thin aluminium). For many industrial welds, 4.6–4.8 is common; for critical analytical or high-precision work, 5.0 becomes rational.

2) Argon 5.0 impurity specifications (ppm) and what they imply

Coregas publishes an explicit Argon 5.0 specification for New Zealand, including individual impurity limits in parts-per-million by volume (vppm):

• Nitrogen < 5 vppm

• Moisture < 1.5 vppm

• Oxygen < 1 vppm

• Total hydrocarbons as methane < 0.5 vppm

• Carbon dioxide < 0.5 vppm

• Gas composition: Argon > 99.999 vol.%

Those numbers are typical of UHP/zero grade argon fleets globally and track closely with other high-purity datasheets; for example, N5.0 argon is commonly documented as ≥99.999% with total impurities around ≤10 ppm (supplier dependent).What the ppm figures mean in practice

• Chromatography/ICP: single-ppm oxygen and sub-ppm moisture/hydrocarbon limits reduce baseline noise, ghost peaks and plasma instability, especially on methods sensitive to O₂/H₂O. Many labs specify 5.0 or better for ICP-MS / ICP-OES and carrier/purge gases for low-level work.

• Advanced welding: on TIG of reactive metals (e.g., titanium) or ultra-thin Al/Cu where porosity and colour are intolerable, 5.0’s O₂/H₂O suppression can reduce rework and post-weld finishing.

3) Argon use cases in NZ: welding vs labs (facts from Coregas)

Coregas’ NZ argon hub positions argon for inerting, blanketing and welding shielding; Argon 5.0 is called out specifically for purging/welding/plasma cutting when higher purity is desirable, and as a carrier gas in gas chromatography.For welders who want a no-rental swap option, Trade N Go Gas™ Argon is available for TIG/MIG across mild steel, stainless, aluminium and copper alloys—handy for light to medium fabricators.

4) Chromatography vs TIG: a decision tree you can defend

Below is a facts-only decision tree to choose between Industrial Argon and Argon 5.0 in New Zealand. It references Coregas’ published use cases and, for laboratory work, typical instrument expectations for GC/ICP.

Step 1 — What’s the application?

• Analytical (GC, ICP-OES, ICP-MS)

  • Minimum requirement: Some ICP-MS methods document high-purity argon ≥99.99% (grade 4.0) as a minimum.

  • Practical best practice: Many labs standardise on Argon 5.0 to further reduce background (lower O₂/H₂O/THC ppm), improve plasma/lamp stability, and simplify cross-instrument supply.

  • Verdict: If the method or QA plan calls for zero/ultra-high purity, specify Coregas Argon 5.0.

• Welding/metal fabrication

  • General TIG/MIG on carbon/stainless steels, aluminium and copper up to a few millimetres: Industrial Argon typically meets quality and cost goals (pair with the right wire/gas mix for MIG).

  • Critical welding (e.g., titanium, ultra-thin Al/Cu, aerospace-style QA, purge-sensitive stainless): Argon 5.0 can pay off via fewer inclusions/porosity and more predictable colour, thanks to <1 ppm O₂ and sub-ppm H₂O/THC.

Step 2 — What does the instrument/process say about flows and stability?

• ICP-MS/ICP-OES: Typical plasma (coolant) gas ~12–15 L/min argon, plus auxiliary and nebuliser flows (approx. 0.5–1.5 L/min each depending on platform). These flows drive monthly gas demand and are a major cost line; optimisation guidance from instrument makers confirms both the ranges and the consumption impact.

• If you’re flow-sensitive: The tighter ppm impurity limits of Argon 5.0 can reduce unplanned downtime chasing plasma out or baseline drift on sensitive methods.

Step 3 — Compliance and documentation

• Analytical: keep the product page spec (ppm table) in the method file; request certificates of conformance with your shipments if your QA requires them (Coregas lists CoC availability per cylinder size).

• Welding: where a PQR/WPS references gas purity, note the grade (4.6/4.8/5.0) in the welding procedure and purchase accordingly from the appropriate Coregas page.

Bottom line: For GC/ICP and critical welding, choose Argon 5.0. For everyday TIG/MIG on common alloys, Industrial Argon or Trade N Go Argon is usually the value pick, with the option to step up to 5.0 for sensitive jobs.

5) Cylinder sizes, outlet types and pressures 

Coregas publishes detailed Argon 5.0 cylinder/cylinder pack specs for NZ, including water volume (m³), full weight, outlet connection and pressure:

• C (0.6 m³), D (1.9 m³), SE (4.9 m³), SG (10.6 m³) at 20,000 kPa with Type 10 outlet

• SG EHP (15.2 m³) at 30,000 kPa with Type 51 outlet

• 6-pack (91.7 m³) and 12-pack (183.4 m³) at 20,000 kPa (Type 10)
  All UN number 1006.

For Trade N Go Gas™ Argon, NZ swap sizes list D (≈2.1 m³) and E (≈4.9 m³) options at 20,000 kPa with Type 10 outlets (availability varies by store). Tip: confirm regulator compatibility (Type 10 vs Type 51) before upgrading to EHP (30,000 kPa) cylinders.

6) LAR (liquid argon) vs cylinder: a practical break-even framework

When does LAR (cryogenic liquid argon) beat cylinders in New Zealand? Coregas supplies argon both as compressed gas and as LAR, and operates Cryoserve™ for cryogenic services. The right answer depends on your monthly volume, delivery profile, storage space, and downtime costs.Here’s a defensible calculation pathway you can drop into your internal memo:

6.1 Quantify monthly demand (m³)

1. Instrument/process flow (L/min) × run hours/day × days/month ÷ 1000 = m³/month.

   • Example (ICP-OES, typical): 12 L/min plasma + 0.5 L/min auxiliary + 0.5 L/min nebuliser ≈ 13 L/min total. At 8 h/day × 20 d/month:
     13 × 60 × 8 × 20 ÷ 1000 = 124.8 m³/month.

   • Example (ICP-MS, typical): 15 L/min plasma + 1.5 L/min auxiliary + 0.9 L/min nebuliser ≈ 17.4 L/min. At 8 h/day × 20 d/month:
     17.4 × 60 × 8 × 20 ÷ 1000 = 167.0 m³/month.

2. Welding shops: use average torch flow (e.g., 8–12 L/min) × arc-on time across bays.

6.2 Express demand as cylinders or packs

Divide m³/month by your cylinder capacity: e.g., SG 10.6 m³ or SE 4.9 m³.

• 167 m³/month ≈ 16 SG cylinders (or ≈ 34 SE cylinders).

• Alternatively, 1 × 12-pack (183.4 m³) covers the month with change.

6.3 Compare total monthly ownership cost

Calculate both sides:

Cylinders route

• Gas cost per m³ × m³/month

• Cylinder rental (if applicable) or deposit amortisation (swap models)

• Delivery fees (frequency × fee)

• Labour/downtime for changeovers, leak checks, and cylinder handling

LAR route

• Liquid argon cost per m³ equivalent (allow for boil-off)

• Tank rental / microbulk charges

• Fill + call-out/delivery fees

• Site safety & compliance (ventilation/clearances)

• Fewer changeovers often reduce labour/downtime

Break-even occurs when the LAR curve dips below the cylinder curve for your m³/month. Because price sheets vary by contract, the simplest rule-of-thumb is volume: if your calculated demand regularly consumes a dozen SG cylinders per month (≈100–130 m³), it’s time to price microbulk or LAR with Coregas. Use their Size Options and Cryoserve pages to scope storage and delivery. Order & scope: Start at the Argon hub, then discuss LAR via Cryoserve (Coregas NZ). For smaller shops or intermittent lab work, Trade N Go Argon can reduce admin via swap cylinders.

7) Safety, hazard class and storage 

• Hazard class: Argon is a non-flammable, non-toxic gas (Class 2.2); it’s an asphyxiant at high concentrations (oxygen displacement). Coregas pages and SDS links reinforce the classification; Trade N Go Argon lists Class 2.2 and GHS non-flammable gas pictogram.

• Storage: Keep cylinders upright, restrained, cool, and ventilated; protect from heat; handle with suitable trolleys. Coregas’ NZ argon page includes straightforward handling/storage FAQ points.

• Site prep for labs: Many ICP makers recommend short gas runs, correct regulator selection, and leak-tight connections, practical steps that limit waste and baseline issues.

Always refer to the SDS for the grade you purchase and follow NZ hazardous substances regulations for cylinder storage and signage.

8) Choosing the right supply model (quick reference)

One-off or intermittent welding / small lab tasks

• Trade N Go Gas™ Argon (D/E swap) avoids rental admin and suits light/medium fabricators or ad hoc R&D.

Regular welding bays and mid-volume analytical labs

• Industrial Argon or Argon 5.0 in SE/SG cylinders or 6/12-packs; align outlet type (Type 10 vs Type 51) and regulator fleet.

High-volume labs / multiple instruments / 24-7 process

• Model LAR/microbulk via Cryoserve; confirm footprint, boil-off, telemetry and call-out SLAs.

9) Worked examples you can reuse in your internal memo

9.1 ICP-MS lab (2 instruments)

• Assumptions: each at ~17.4 L/min total Ar (plasma+aux+nebuliser), 8 h/day, 20 d/month → 167 m³/month per instrument. Two instruments ≈ 334 m³/month.

• Cylinders: at 10.6 m³ (SG) → ~32 SG cylinders/month; at 4.9 m³ (SE) → ~68 SE cylinders/month.

• Discussion: even with a 12-pack strategy, changeover labour and delivery frequency are material. At this volume, LAR usually deserves a quote.

9.2 TIG-heavy fabrication shop (4 bays)

• Assumptions: average 10 L/min per bay when arc-on; 4 hours arc-on/day; 22 days/month → per bay 52.8 m³/month, total 211 m³/month.

• Supply: two 12-packs (183.4 m³ each) per month might be over-spec; one 12-pack + top-up could work. If turn-around speed and floor space are tight, compare LAR on logistics.

Note: swap in your own flows, hours, and cylinder sizes; the math is simple and defendable.

10) Quick procurement checklist (so you don’t miss anything)

• Grade required (4.6/4.8/5.0) and ppm limits (for 5.0, record the Coregas spec table).

• Application (welding vs GC/ICP) and any method QA references.

• Flow profile (L/min × hours) and m³/month calculation.

• Package (D/SE/SG/SG-EHP; 6- or 12-packs) and outlet type (Type 10 vs Type 51).

• Supply mode (swap, rental, or LAR via Cryoserve) and delivery cadence.

• Safety (Class 2.2 asphyxiant, storage, SDS on file).

11) Where to buy / who to talk to 

• Browse and compare grades: Coregas Argon hub (industrial + lab), including Argon 5.0.

• Go straight to high-purity: Coregas Argon 5.0 (includes impurity ppm table, sizes, Type 10/51 outlets, and CoC links).

• Swap option: Trade N Go Gas™ Argon (no rental, D/E sizes).

• Planning for LAR: scope with Cryoserve and Size Options.

Conclusion

For NZ labs chasing low detection limits and calm baselines—or fabricators tackling reactive materials and precision joins—Argon 5.0 is the credible, documentable upsell. The specification is plain: ≥99.999% argon with O₂ < 1 ppm, H₂O < 1.5 ppm, THC < 0.5 ppm and other impurities tightly capped; Coregas publishes this on the product page alongside cylinder capacities, outlet types, and CoC availability. Pair that with a clear view of your flow-driven monthly demand, and you can decide when to step beyond cylinders into LAR with Coregas’ cryogenic services.

Next actions

• Scan Argon 5.0 specs and sizes → order or request a quote.

• For welding/workshop use, compare with Industrial Argon and Trade N Go swap options.

• If your m³/month suggests it, scope LAR/microbulk with Cryoserve.