Quality control that keeps your line running

The four QC stages every SBKJ machine passes through

SBKJ quality control is structured around four explicit checkpoints. Each one has a documented procedure, a responsible engineer, and a record that travels with the machine for the lifetime of the asset. None of the four can be skipped, and no machine ships without all four signatures complete.

1. Incoming material and component inspection

Every coil, casting, motor, gearbox and PLC that enters the Jiangyin factory is logged against an approved supplier list and inspected against a documented incoming standard. Steel coils are checked for thickness, surface coating weight (Z180/Z275 galvanising), edge condition and coil ID. Castings and structural steel are dimension-checked against the drawing. Electrical components are verified against the original packaging serial number and the manufacturer's certificate of compliance — SBKJ does not accept ungraded or unbranded electricals on any production machine. Components that fail incoming inspection are quarantined in a separate hold area and returned to the supplier with a non-conformance report. The non-conformance log is reviewed quarterly and feeds back into the approved-supplier list.

2. In-process inspection during manufacture

SBKJ machines are built around a sequence of machining and assembly stations: structural steel cutting and welding, machined surface preparation, sub-assembly of forming heads or fold stations, electrical cabinet build, and final integration. Each station has a dedicated inspection step with a checklist signed by the operator and counter-signed by the QC engineer for that area. Critical-to-function dimensions — spindle alignment, roller parallelism, hydraulic pressure setting, motor torque calibration — are recorded against the drawing tolerance, not just visually checked. Any deviation triggers a re-work order before the sub-assembly moves to the next station. The machine cannot reach the test bay until every in-process checklist is complete.

3. Functional and electrical machine testing

Once the machine is fully assembled, it moves to the dedicated test bay where SBKJ runs the full electrical safety, PLC program, mechanical run-in and load test. Insulation resistance, earth bond continuity and emergency stop function are tested to IEC 60204-1 standards before the machine is energised. The PLC program is loaded from a checksummed master copy and verified against the build sheet. The machine then runs the full diameter program (or duct size program for rectangular machines) at no-load and at design load using SBKJ stock galvanised coil. Cycle times, motor currents, hydraulic pressures and seam quality are recorded. Any deviation from the design envelope triggers a hold and an engineering review.

4. Pre-shipment factory acceptance test (FAT)

The FAT is the final QC stage and the most important one for the buyer. SBKJ schedules the FAT date with you at order confirmation and sends a formal invitation 2–3 weeks ahead. The test runs 1–2 days at the Jiangyin factory and includes: a walk-around of the assembled machine; a full diameter or duct size program run using your nominated coil and your target output; measurement of seam continuity, straightness, cut squareness, and tolerance; review of the build sheet, electrical schematic, lubrication chart and operator manual; and a Q&A session with the SBKJ project engineer who will travel for commissioning. The buyer's authorised engineer signs the FAT report alongside the SBKJ engineer. A signed FAT report is the trigger for final payment release on most contracts.

Standards and certifications

SBKJ Group operates under the following formal standards and certifications:

• ISO 9001:2015 — quality management system covering the design, manufacture, FAT and after-sales service of HVAC ductwork machinery at the Jiangyin factory. Audited annually by an accredited certification body.
• CE marking — under the EU Machinery Directive 2006/42/EC, with technical file, risk assessment and Declaration of Conformity travelling with each machine that ships to a CE territory.
• SMACNA HVAC Duct Construction Standards — SBKJ machines are designed to produce duct that meets SMACNA gauge, seam and pressure-class requirements out of the box.
• EN 1505 / EN 1506 — rectangular and round duct dimensional standards for the European market; SBKJ tooling is available in metric and imperial profiles to match.
• AS/NZS 4254 — Australian and New Zealand HVAC duct construction standard, supported by the SBKJ Australia office in Box Hill North, VIC.

Document pack that ships with every machine

Every SBKJ machine arrives at your factory with a complete document pack in a sealed waterproof envelope inside the electrical cabinet. The standard contents are: signed FAT report; CE Declaration of Conformity (where applicable); ISO 9001 certificate copy; operator manual in English (and additional languages on request); electrical schematic; pneumatic and hydraulic schematic where applicable; spare parts list with SBKJ part numbers; lubrication chart; and warranty card. Buyers can also request a detailed QC trace report covering every in-process checklist sign-off — this is sometimes required by buyers in regulated industries (pharmaceutical, semiconductor, aerospace) and SBKJ will produce it within 5 working days of the request.

What happens if something fails QC after delivery

SBKJ standard warranty is 12 months from commissioning, covering all mechanical and electrical components except wearing parts. Within the warranty period, SBKJ will diagnose any quality-related fault remotely (we hold the machine schematic and the PLC backup) and either ship a replacement part by air freight or dispatch a technician to the buyer's factory, depending on the fault. After the warranty period, SBKJ continues to supply spare parts at catalogue prices for the lifetime of the machine — the oldest SBKJ machines still running in the field were commissioned in the late 1990s and we still keep their parts in stock or in the production schedule. Speak to the SBKJ technical support team early; the workshops with the lowest downtime are the ones who pick up the phone before a problem becomes a stoppage.

Frequently asked questions

Is SBKJ Group ISO 9001:2015 certified?

Yes. SBKJ Group holds an active ISO 9001:2015 quality management certificate covering the design and manufacture of HVAC ductwork machinery at the Jiangyin factory. The certificate is renewed on schedule and audited by an accredited certification body.

Are SBKJ machines CE marked?

Yes. SBKJ machines are CE marked under the EU Machinery Directive 2006/42/EC. Each machine ships with a Declaration of Conformity, the technical file references and the operator manual translated into English (with additional languages available on request).

Can I attend the factory acceptance test?

Yes — SBKJ encourages every buyer to send an authorised engineer to the FAT. The test typically runs 1–2 days at the Jiangyin factory using your nominated coil and your target program. We also offer a video FAT for buyers who cannot travel.

What does the pre-shipment inspection cover?

Pre-shipment QA covers electrical safety, PLC program checksum, mechanical alignment, lubrication, packing integrity, container sealing, and final document pack (FAT report, CE Declaration of Conformity, operator manual, parts list, electrical schematic and warranty card).

What is the warranty period?

Standard SBKJ warranty is 12 months from commissioning, covering all mechanical and electrical components except wearing parts. Extended warranty packages are available on the larger lines such as SBAL-V and SBTF-2020.

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