A pre-shipment reactor inspection runs to 12 checkpoints on the factory floor in one day: the document pack, dimensions against the approved drawing, ultrasonic wall thickness, a hydrostatic test at 1.25 × design pressure (GB/T 150) or 1.3 × MAWP (ASME), a jacket leak test, a full-coverage high-voltage lining test, lining thickness measurement, agitator and shaft concentricity, seal and drive alignment, internal finish, nozzle and flange inspection, and packing. Do not release the balance payment until all twelve are recorded with numbers and photographs on one signed sheet.
We are KAVORTE, an independent sourcing and engineering office in Zibo, Shandong — the centre of China's glass-lined equipment industry. We do not own a factory. What follows is the list we run on the floor before a vessel is allowed into a container, written so a technical buyer can print it and use it without us.
1. Documents — check these before you look at the steel
Paperwork is where the other eleven items get their meaning. Work against the numbered specification confirmation sheet you approved before fabrication started, not against a catalogue.
- Material certificates to EN 10204 3.1 for shell, heads, jacket and flanges. The heat numbers must be traceable to the plate, not only to the paper.
- Weld map, welder qualification records and NDT reports (RT or PT) for the main seams.
- Pressure-test record showing the gauge serial number and a calibration certificate dated within the last 12 months.
- Lining records: thickness readings per zone, plus the high-voltage test record.
- Nameplate data: model, nominal volume in litres, design pressure in MPa, design temperature in °C, lining type, serial number, year.
- Third-party and system documents where they apply — SGS or equivalent, CE/PED, ISO 9001, GMP for pharmaceutical duty.
One line on the sheet deserves special attention: the approved application media. For glass-lined vessels it reads as inorganic and organic acids, organic solvents and weak bases at various concentrations, and explicitly not hydrofluoric acid, fluoride-bearing media, phosphoric acid at 30 % or above above 180 °C, or strong alkali above pH 12 at 100 °C. If the nameplate and dossier do not carry that restriction, raise it before shipment, not after commissioning.
2. Dimensions and wall thickness
Nominal volume fixes the model series and nothing else. Internal dimensions, heat-transfer area, agitator power and unit weight follow your duty, so measure them in millimetres against the drawing.
- Internal diameter, straight-side height, overall height.
- Nozzle size, projection, orientation and flange PCD with bolt-hole count. Dry-fit a gasket on the manway and the bottom outlet.
- Jacket and coil nozzle positions; on a half-pipe coil, check the pitch.
- Support ring or leg bolt circle.
- Ultrasonic thickness on shell, heads and jacket — at least four points per course, compared with both the drawing and the mill certificate.
A wall reading below the drawing figure with no corrosion allowance written beside it is a hold, not a discussion.
3. Pressure and leak testing
Hydrotest the inner vessel and the jacket separately. The jacket is the one that gets skipped, and the one that leaks into a customer's plant six weeks later.
- Hold the inner vessel at 1.25 × design pressure under GB/T 150, or 1.3 × MAWP if the build follows ASME.
- Hold for at least 30 minutes and read the gauge yourself. A falling needle is a result; a signed certificate with no gauge number is a rumour.
- Air or soap-bubble test the jacket, coil and every nozzle weld. Air finds paths that water never will.
- Note the fill-water temperature. Glass lining tolerates cold shock to 110 °C and heat shock to 120 °C; filling a still-warm vessel quickly can crack a lining before it ever ships.
4. Lining integrity: spark test and thickness
The high-voltage, or spark, test is the most important check on a glass-lined vessel and the one most often run before the buyer arrives.
- Insist on witnessing it. The probe must cover every wetted surface — shell, both heads, baffles, manway bore, bottom outlet, nozzle bores, and the agitator shaft and blades if they are glass-lined.
- Test voltage is the figure on your specification sheet; for glass lining it commonly sits between 10 and 20 kV DC. The probe must be drawn at a steady speed — rushed passes clear linings that will fail in service.
- Measure lining thickness with a magnetic gauge at the bottom head, shell, top head and around the inlet zone. The bottom head and impeller zone are where erosion starts.
- Look as well as test: crazing, dark patches, chips on flange faces and a rough weld cap under the lining show up visually before they show up electrically.
- For PFA, PTFE, ETFE (F40), ECTFE (F30) or FEP (F46) linings, confirm the holiday-test method with the lining supplier — spark and wet-sponge testing suit different thicknesses — and check the lining is continuous through every nozzle bore and across the flange sealing face.
5. Agitator concentricity, seal and drive
This is where a vessel that passed every pressure test still fails to run quietly.
- Measure shaft runout with a dial indicator at three heights: seal face, mid-shaft, and just above the impeller. Record the numbers in millimetres against the drawing tolerance. "Within tolerance" with no reading is not a result.
- Check impeller-to-wall clearance and bottom clearance at the closest point, with the shaft in its running position, and check shaft verticality inside the vessel.
- On a mechanical seal, check face condition, spring compression, and that flush and quench ports line up with the drawing. On a packed Type K build, check packing grade and lantern ring position.
- Confirm motor rotation direction before the coupling goes on, then jog the drive. If it can run unloaded for 30 minutes, record bearing temperature and vibration.
6. Finish, flanges and fittings
Internal finish is a number, not an adjective. If the duty is pharmaceutical or the vessel is described as GMP, the drawing should state a surface roughness figure and require no dead corners.
- Flange facing type, flatness and roughness; bolt holes aligned to the PCD, gaskets dry-fitted.
- Bolt material and thread condition — galvanised, stainless or fluoropolymer-lined, as specified.
- Baffle, dip tube, temperature pocket and sparger positions against the drawing.
7. Packing, preservation and release
Everything above can still be undone in twenty minutes of careless packing.
- Photograph the internal lining before the vessel is closed. Those photographs are the only evidence you will have in a transit claim.
- Confirm nozzle protection, desiccant inside stainless vessels, and the cradle or saddle arrangement against the packing plan.
- Check that shipping weights come off the drawing, not off the model designation.
- Match the nameplate against the dossier one last time, then sign the release.
8. How to run the twelve on the day
The order matters: documents, dimensions, pressure, lining, mechanical, finish, packing. Once the vessel is crated, every earlier item costs more to re-check.
For a 3,000 to 10,000 L vessel, plan one working day on the floor, two if there is a witnessed hydro, a third-party inspector, or a large agitator that must be assembled and run. Set the hydrostatic and spark tests as hold points and tell the factory not to run them before you arrive.
If you cannot travel, a third-party inspector with a written scope works — provided the scope names the twelve points and requires photographs of the lining, the gauge during the hydro test, and the dial indicator readings. An inspector who has never seen a glass-lined vessel will sign whatever is placed in front of him.
The cost is easy to justify. A 3,000 L glass-lined reactor with a jacket and a mechanical seal lands between USD 8,000 and USD 14,000 ex-works. One day of inspection is a fraction of one lining repair.
What to do next
Print the twelve points, take them to the factory, and fill in every line with a number, a serial number or a photograph — no ticks without evidence. Read your numbered specification confirmation sheet the night before; every deviation you find on the floor is one that someone approved or someone assumed. If the factory will not let you or your inspector witness the hydrostatic and high-voltage tests, treat that refusal as the answer to the question you were about to ask.