Container module factory production line

Container Building Engineering, Specifications & Quality Control

From certified welding and UT inspection to water-tightness testing — the technical data architects, engineers and developers need to evaluate our container modules.

AWS-certified weldingClassification society certifiedUT inspection of full-penetration welds15 controlled production steps

4 Engineering Essentials for Your Project

Structure, foundation, fire safety and ancillary steelwork — organized for your local engineer and permitting process.

Concept illustration — not a construction drawing
01 / STRUCTURE

Structural design

Wind, snow and seismic loads are calculated for your site, designed with reference to local codes (e.g. ASCE 7, Eurocode, AS/NZS). Drawings and calculations are provided for review by your local engineer of record.

Structural calcsCAD drawingsLoad reinforcementPermit documents
ColumnBase plateFoundationAnchor boltsConcept illustration — not a construction drawing
02 / FOUNDATION

Foundation connections

Anchored to a foundation, not just placed on it. Column bases and high-strength bolts transfer gravity and seismic loads to the foundation.

Exposed column baseAnchor boltsHigh-strength boltsConnection details
SteelInsulationBoard& finishConcept illustration — not a construction drawing
03 / FIRE SAFETY

Fire safety

Fire-rated materials and assemblies are specified to meet your project's fire requirements.

Non-combustible boardFire-resistive coatingLow-VOC materials
External steel stairs and walkway connected to container modules
04 / STEEL WORKS

Ancillary steelwork

External stairs, walkways, balconies and grandstand structures are fabricated in the same factory and bolted on site.

StairsWalkwaysBalconiesGrandstands

Traceable Quality: From Mill Certificate to Inspection Report

Every structural member is traceable — from material certificates and receiving inspection to weld testing and final records, managed per project.

ST
SteelStructural grades
MC
Mill certMaterial verified
IN
ReceivingDimensions & thickness
FAB
FabricationIn-process checks
UT
UTFull-penetration welds
QC
RecordsInspection dossier
STEELStructural steel gradesQ355, Corten and ASTM grades selected to suit the design.
UTUT on full-penetration weldsPerformed and reported by qualified inspectors.
QCFull QC documentationMill certs, UT, visual, assembly, coating, final inspection and VOC reports.
Receiving inspection: mill certificates, dimensions, thickness and surface condition.
Receiving inspection: mill certificates, dimensions, thickness and surface condition.
UT inspection of full-penetration welds in columns and main beams.
UT inspection of full-penetration welds in columns and main beams.
View steel grades and documentation
SteelTypical useStandard
Q355BMain frame (columns, beams)GB/T 1591
Corten (weathering steel)Corrugated walls, roof—
ASTM grades (A36 / A572 etc.)On requestASTM

Mill certificates available for all structural steel. Inspection reports issued per project.

MaterialsMill certificates (material verification)
WeldingUT reports, visual and assembly inspection records
CompletionCoating, final inspection and VOC reports

15 Controlled Steps from Drawing Approval to Shipment

Six phases bring UT, water-tightness, VOC testing and shipment release into a clear manufacturing sequence.

0

Drawing review & approval

Before production

1

Material receiving

Step 01

2

Fabrication & welding

Steps 02–06

3

Weld testing & coating

Steps 07–10

UTCoating
4

Water-tightness & interiors

Steps 11–13

Water testVOC
5

Final inspection & shipment

Steps 14–15

Release
View all 15 steps and quality-control details
Shop drawing review and approval Drawings are reviewed and approved before production Drawings 6,058 Review Dimensions Openings Specification Approved

Before production: shop drawing review & approval

After order confirmation, we review the design drawings and specification, prepare clarification questions and submit shop drawings. Review the dimensions, openings, specification and materials. Manufacture begins after your approval. Requested changes are incorporated and returned for review.

01Incoming material inspectionCheck mill certificates, plate thickness, dimensions and surface condition.
02Component processingNC cutting, bending and pressing prepare individual components.
03Component weldingCertified welders carry out the smaller welded assemblies.
04Sub-assemblyComponents are positioned in jigs and assembled into the frame.
05Main assembly weldingThe complete structure is welded with distortion control.
06Rotating-jig weldingCertified welders position critical areas for downhand welding.
07UT inspectionFull-penetration welds are tested and reports prepared.
08Shot blastingSurface preparation to a level equivalent to Sa 2.5.
09Coating applicationPrimer, intermediate and topcoat layers are applied.
10Coating thickness inspectionMulti-point measurements check the specified coating thickness.
11Water-tightness testingA spray test of 30–60 minutes or longer checks for leaks.
12Interior constructionSteel stud framing, insulation, non-combustible boards, finishes and concealed piping and wiring.
13Formaldehyde & VOC testingIndoor concentrations are measured after interior work.
14Finished-product inspectionCheck dimensions, finishes, electrical energisation, water supply, doors and windows.
15Packing & shipmentPacking, lashing & CSC plate check; shipped FOB / CIF Qingdao after release approval
Quality control by production phase
PhaseResponsibilityInspectionRecordsApplicable criteria
0 Drawing review & approvalSales & designClarifications and shop drawing approvalDesign drawings, specification, clarification records and programmeDesign drawings & specification
1 Material receivingMaterials & quality assuranceReceiving inspectionMill certificates and material delivery listInternal material-control procedures & inspection criteria
2 Fabrication & weldingProduction (welding supervisors and welders)Assembly inspectionAssembly inspection recordsWelding procedures, fabrication instructions & shop drawings
3 Weld testing & coatingQuality assurance (UT and product inspection supervisors)Visual, non-destructive and coating inspectionsNDT reports, visual and coating inspection recordsNDT criteria & coating procedures
4 Water-tightness & interiorsProduction & quality assuranceWater-tightness, formaldehyde & VOC testingTest and measurement resultsInternal standards & project specification
5 Final inspection & shipmentQuality assuranceProduct inspection, witness inspection and dispatch inspectionProduct inspection reports, witness records, packing & dispatch listsInspection criteria & packing/dispatch procedures

When an inspection does not passNonconformity report → corrective action → re-inspection. Shop drawings that are not approved are revised and submitted again.

Request the full QC flow chart →

Standard Container Building Dimensions

Standard 20ft and 40ft high-cube formats, with additional lengths and custom sizes available.

20 FT HIGH CUBE

Approx. 14.8 m² (159 sq ft)
6,058 × 2,438 × 2,896 mm(19'10½" × 8' × 9'6") · Length × width × height

40 FT HIGH CUBE

Approx. 29.7 m² (320 sq ft)
12,192 × 2,438 × 2,896 mm(40' × 8' × 9'6") · Length × width × height
Standard & High Cube10 ft / 30 ftCustom sizesMulti-unit & stacked layouts

Internal dimensions depend on insulation and interior specification and are shown on project drawings. Floor areas are approximate external footprints.

Choose Your Level of Factory Completion

Choose Shell, Base-Fit or Turnkey according to the work planned locally. Final electrical and plumbing connections are made on site by locally licensed trades.

LEVEL 01

Shell

Structure and exterior completed in the factory; suited to projects with locally designed interiors.

StructureInsulationSubstrateServicesFinish
FactoryStructure, cladding, roof, openings, anti-corrosion coating
On site (local contractor)All insulation, interiors and services
RecommendedLEVEL 02

Base-Fit

Factory-installed insulation, substrates and concealed service routes, with finishes completed locally.

StructureInsulationSubstrateServicesFinish
FactoryPlus insulation, steel stud framing, fire-rated board, concealed wiring & plumbing
On site (local contractor)Finishes, fixtures, final connections & inspection
LEVEL 03

Turnkey

Factory-completed finishes and equipment, suited to repeated room layouts such as hotel accommodation.

StructureInsulationSubstrateServicesFinish
FactoryPlus finishes, doors & windows, bathroom, lighting, VOC test
On site (local contractor)Setting, joining, final utility connections & inspection
01Steel1.6 mm (1/16 inch) corrugated steel
02Spray PU30 mm (1¼ inch)
03Mineral wool50 mm (2 inch)
04Vapor barrier0.2 mm
05Fire-rated gypsum board12.5 mm (½ inch)
06FinishSelected wall finish

Example wall build-up: total approx. 95 mm (3¾ inch). Materials and thicknesses vary with the project specification.

Insulation & condensationSpray PU, mineral wool and a vapor barrier. Insulation thickness can be adjusted for cold climates.
AcousticsAbsorbent materials and air cavities are considered around the intended use.
Corrosion protectionShot blasting and multi-layer coating, with enhanced protection proposed for coastal locations.
Factory: concealed electrical routes before interior finishes.
Factory: concealed electrical routes before interior finishes.
Factory: a completed guest-room bathroom.
Factory: a completed guest-room bathroom.
On site: final drainage connections after positioning.
On site: final drainage connections after positioning.

Certifications & Compliance

Our manufacturing is backed by recognized welding and classification society certifications, with full documentation for every project.

01

AWS-certified welding

02

Classification society certified (LR · KR · BV · RS · ABS · CCS)

03

CSC plate on every container

04

Project inspection dossier: mill certs, UT, coating and final inspection reports

Modular vs. Conventional Construction

ComparisonYustellar ModularStick-built (timber frame)Concrete / masonry
ProgrammeFactory manufacture and foundation work can proceed in parallelSequential construction on siteSequential construction on site; curing time required
Site workMainly positioning and service connectionsAll stages on siteAll stages on site
StructureSteel frameTimber frameReinforced concrete / masonry
Relocation & reusePossible when planned into the designDifficultDifficult
Site wasteEasier to limitModerateHigher

General comparison. Site duration depends on project scale, specification and installation conditions. Factory manufacture and permitting are separate parts of the programme.

Technical & Project FAQ

How many stories can you stack?
PLACEHOLDER — Stacking limit to be confirmed.
Are the modules the same size as ISO shipping containers?
Standard external dimensions use 20ft and 40ft high-cube formats. Interior dimensions depend on insulation and finishes and are shown on project drawings. 30ft and custom sizes are also available.
Which finish level should I choose?
Choose Shell when the interiors will be designed and completed locally, Base-Fit when you want insulation and concealed services installed in the factory, or Turnkey for repeated finished rooms. Tell us the intended use and the work you plan to complete locally.
How are plumbing and electrical handled?
Concealed piping and wiring can be installed during manufacture. Final electrical and plumbing connections are made on site by locally licensed trades. PLACEHOLDER — Destination-specific wiring and component requirements to be confirmed.
How long do the buildings last?
Service life depends on the installation environment, surface treatment, corrosion protection, use and maintenance.
Can you support local permitting?
We provide drawings and structural calculations for your local engineer of record.
Can you build for coastal or cold climates?
Yes. Enhanced corrosion-protection coatings can be proposed for coastal locations, and insulation thickness can be increased for colder climates.
What are your shipping terms?
FOB / CIF Qingdao.
Is there a minimum order?
Projects of 3+ units; storage containers from 1 unit.
Do you provide grandstand design load data?
Yes, design load data / structural reports available.

Request Technical Documents

Standard module drawings, sample structural calculations and certification documents — available for your design review. No drawings yet? We can still help.

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