Jiangsu Xijie New Energy · Nuclear equipment

20kW 3D laser cutting robot delivered to Jiangsu Xijie

Used for 3D hole cutting and bevelling on nuclear pressure vessel shells and tower sections. The system passed acceptance first time; hole-group cutting is about 3 times faster than the previous plasma process, and the holes need no grinding.

The production task

A single shell can need over a hundred holes on its curved surface, from Φ30 to Φ600, positioned relative to girth seams and the shell datum line. The old route of marking out, hand plasma cutting, grinding, dye-penetrant testing and repair left heavy dross and wide heat-affected zones, hole positions varied, and delivery was held up at this last operation.

The system approach

Haibao delivered a gantry-type, six-axis shell hole cutting cell: the gantry handles large-range positioning, the six-axis robot handles 3D orientation, and two-station heavy turning rolls index the shell. Offline programming converts the 3D shell model straight into cutting paths, a full ring of holes is cut in one set-up, and the dross-free cuts go straight to fit-up and welding.

Fibre laser output: 20kW
Hole position accuracy: ±0.05mm
Cut squareness, no grinding: ≥99.5%
Hole-group throughput vs plasma: 3×

Customer

Why hole cutting on nuclear shells became the bottleneck

Jiangsu Xijie New Energy Engineering Technology, based in Yixing, Jiangsu, is a national high-tech enterprise making nuclear chemical, nuclear power and defence waste treatment equipment, ASME code products and pressure vessels. Nuclear products demand far higher cut quality, hole tolerances and traceability than ordinary pressure vessels.

Long cutting and grinding time per shell held up delivery
Hole quality depended on the operator; rework and inspection costs stayed high
Frequent hole-type changes meant long marking, set-up and trial cuts
Nuclear work requires tighter cut quality, tolerances and traceability

Hole group on the shell: varied diameters and spacing, clean bores with no dross

Project file

What was delivered

Customer: Jiangsu Xijie New Energy Engineering Technology Co., Ltd.
Delivered: 2026
Applications: Nuclear pressure vessel shells, nuclear tower sections, nuclear waste treatment vessels, large stainless and carbon steel shells
Capabilities: 3D hole cutting, intersecting holes, slotted and profiled holes, one-pass bevels, batch hole arrays
Equipment: Gantry, six-axis robot, 3D laser cutting head, two-station heavy turning rolls, CNC and offline programming
Result: Accepted first time; hole cutting reduced from "cut + grind + re-inspect" to "cut + sample check"

Requirements

Four requirements from the customer

Measurable hole accuracy

Hole centres held within ±0.1mm regardless of shift or operator, with traceable inspection records.

No grinding

No dross or oxide build-up, good squareness, and holes ready for fit-up and welding straight after cutting.

Fast changeovers

Shell diameter, hole type and spacing change often, so paths must come from offline programming with minimal set-up downtime.

Large parts

Shells of Φ1–6m, around 12m long and tens of tonnes must have all hole groups cut in one set-up.

The system

A 3D laser cutting cell built for large shells

The gantry positions, the robot orients and the turning rolls index the shell. Working together, they cut a full ring of holes in one set-up.

Height-following head

As the shell turns, the surface height changes. Height following keeps the nozzle distance constant so the kerf does not widen or fail to cut through.

Fully enclosed cable chains

Fibre, gas, water and control lines move with the beam without repeated sharp bends, which is key to long-term stability of a high-power laser.

No grinding marks

No grinder marks on the shell and no spatter around the holes show that cutting parameters and assist gas are well matched.

Holes driven by the 3D model

Hole positions come from the model, not from marking and manual set-up. Varied diameters, spacing and profiles are parameters in software, with no hardware change.

A full ring in one set-up

The system generates indexing angles and robot poses automatically: the shell turns into position, the head moves in, a ring of holes is cut, then the next angle.

Traceable data

Cutting paths and inspection data are archived to meet nuclear traceability requirements.

Cut quality

Direct evidence of no-grind holes

Four things decide laser cut quality: a clean profile, no dross, square edges and a controlled heat-affected zone.

Laser vs plasma

Clean profile

Slotted holes have smooth end radii, no skew along the long axis, and match the model.

Plasma: heavy dross, needs chipping

No dross

No dross on the lower edge, so no chipping or grinding before the next operation.

Plasma: about 90–95%

Squareness ≥99.5%

The cut face is nearly square with little difference between top and bottom, giving a stable bevel allowance.

Plasma: wider, with oxide layer

Narrow heat-affected zone

High energy density and short exposure limit changes to the base metal, lowering welding risk later.

Specifications

Typical configuration of the delivered system

Shell diameter, length, load and gantry travel can be tailored to the customer’s product range. Cutting thickness depends on material, assist gas, hole size and bevel and is confirmed by process trials.

20kW fibre laser

Laser power

Cuts medium-thick plate in one pass.

3D laser cutting head

Cutting head

Height following with capacitive sensing.

Twin columns + box beam

Gantry

Stress-relieved; X ≤12000mm, Z 2500mm.

Φ1000 – Φ6000mm

Shell range

Length ≤12000mm, load ≤60t.

±0.05mm / ±0.03mm

Accuracy

Positioning / repeatability; hole consistency CPK ≥ 1.33.

Carbon ≤30mm / stainless ≤20mm

Thickness

Oxygen assist for carbon, nitrogen for stainless, subject to trials.

CNC + offline programming

Programming

Imports 3D models.

Optional

Options

Laser edge finding, vision positioning, fume extraction, laser safety fencing.

Delivery

The machine is the carrier; the parameters are the core

The real time on this project went not into installation but into proving the parameter sets for each of the customer’s common materials, thicknesses and hole types, then fixing them as process cards.

01
Requirements and feasibility
Confirm shell range, hole list, accuracy and output targets, then recommend a configuration.
02
Sample cuts and parameter proof
Cut the customer’s actual material to verify quality, squareness and speed, setting a parameter baseline.
03
Build and factory acceptance
Gantry, robot and turning rolls are run together, with accuracy checks and dry runs in the factory.
04
Installation and commissioning
Foundation levelling, rail laying, full-system tuning and test cuts on real shells.
05
Process lock-in and training
Parameter sets fixed, program templates handed over, and training in operation, programming and maintenance.
06
Acceptance and ongoing service
Item-by-item acceptance to the technical agreement, then warranty with remote diagnosis and site response.

FAQ

Laser hole cutting on nuclear shells

How thick can 20kW cut?

About 25–30mm carbon steel with oxygen and 15–20mm stainless with nitrogen. Thicker shells usually combine laser hole cutting and bevel pre-cutting with plasma or machining for the final form. Exact limits are proven by trials and written into the agreement.

Why laser instead of plasma?

Plasma leaves dross, oxide and a wide heat-affected zone, so nuclear shells need grinding and dye-penetrant testing. Laser gives a narrow kerf, small HAZ and square edges, removing the grinding step and improving hole accuracy from millimetres to ±0.05mm.

How is hole accuracy assured?

A rigid twin-column gantry holds stiffness over long travel, the robot sets 3D orientation and the rolls index the shell. Laser edge finding and the shell datum define the work coordinates, and offline programming turns the 3D model into paths.

How large a shell can it handle?

The standard model covers Φ1000–Φ6000mm, up to 12000mm long and 60t. Longer gantry travel and heavier, wider turning rolls can be built for larger parts.

Is grinding still needed?

With matched parameters there is no dross and squareness is ≥99.5%, so holes go straight to welding or fit-up. Only pierce and finish points may need light touch-up per the procedure.

Lead time and service?

About 90–120 days for the standard configuration, including installation, operation and programming training and parameter lock-in. Remote diagnosis and 48-hour site response during warranty.

On site

The system in Jiangsu Xijie’s workshop

The first two images are 3D layout drawings; the rest are photos from the customer’s workshop.

3D layout: twin-column gantry, six-axis robot, laser head, two-station rolls and floor rail

Gantry side view: X/Y/Z axes plus six-axis 3D orientation

Workshop view: vertical ram, cutting robot and a nuclear shell with holes cut

Cutting head close-up: nozzle following the curved surface at constant standoff

Hole group on a large sectioned shell, with varied diameters and spacing

Slotted hole profileSquare cut, no regrindingSmooth edge, no drossLayout line / alignment markCoaxial locating hole

Slotted hole macro: smooth profile, no dross, layout marks and locating hole kept

1Slotted hole profile
2Square cut, no regrinding
3Smooth edge, no dross
4Layout line / alignment mark
5Coaxial locating hole

Customer feedback

What the customer says

Commissioning went smoothly after delivery. Speed and consistency on shell hole groups are clearly better than our old plasma-plus-grinding process, and the holes hardly need any rework. Haibao’s engineers supported production on site for over two weeks and we worked out the parameters together, so now we can handle changeovers ourselves.

— Project Manager, Jiangsu Xijie New Energy Engineering Technology

Can your shells be laser cut? Send us the material, thickness, hole sizes and hole list, and within 3 working days we will assess feasibility, recommend a configuration and estimate cycle time.

Discuss your project

Specifications are the typical configuration of the delivered system; the technical agreement and factory acceptance report govern. Laser vs plasma comparisons come from measurements before and after delivery on this project and vary with material, thickness and parameters.

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Tell us about your material, workpiece and production needs. Let’s find a practical starting point.