CN Quality Check
Standards Comparison Tool
EXECUTIVE SUMMARY
This report compares GB/T 8806-2008 (塑料管道系统 塑料部件尺寸的测定, Plastics piping systems — Determination of dimensions of plastics components) with ISO 3126:2005/2021. The Chinese standard is technically identical (IDT) to ISO 3126:2005 but not updated to ISO 3126:2021. Procurement implication: products tested to GB/T 8806-2008 are directly acceptable under ISO 3126:2005, but may require additional verification for ISO 3126:2021 compliance.
APPLICABLE CHINESE STANDARDS
| Standard No. | Title (Chinese) | Scope | Mandatory/Recommended | Status |
|---|---|---|---|---|
| GB/T 8806-2008 | 塑料管道系统 塑料部件尺寸的测定 (Plastics piping systems — Determination of dimensions of plastics components) | Test method for measuring dimensions of plastic pipes and fittings | Recommended (GB/T) | Current (现行) |
STANDARD TIER CLASSIFICATION
| Standard | Tier | Description |
|---|---|---|
| GB/T 8806-2008 | TIER 2 — Test Method | Defines measurement methods for plastic pipe dimensions |
| ISO 3126:2005 | TIER 2 — Test Method | Defines measurement methods for plastic pipe dimensions |
| ISO 3126:2021 | TIER 2 — Test Method | Updated edition with optical scanning methods |
Tier match: Both are TIER 2 — valid comparison.
SCOPE BREAKDOWN
Plastic pipe dimension measurement
Chinese standard: GB/T 8806-2008: 塑料管道系统 塑料部件尺寸的测定 (Plastics piping systems — Determination of dimensions of plastics components)
International equivalent: ISO 3126:2005 (superseded by ISO 3126:2021)
Equivalence: IDT to ISO 3126:2005; MOD to ISO 3126:2021
Standard tier match: Both TIER 2 — valid comparison
Parameter comparison table:
| Parameter | Chinese Standard Value (Clause) | International Value (Clause) | Deviation | Mutual Recognition | Procurement Impact |
|---|---|---|---|---|---|
| Measurement method | Micrometer/caliper (GB/T 8806-2008 §5) | Micrometer/caliper (ISO 3126:2005 §5) | Identical | 直接互认 (Direct mutual recognition) | LOW |
| Accuracy requirement | ±0.02 mm for ≤10 mm (GB/T 8806-2008 §6) | ±0.02 mm for ≤10 mm (ISO 3126:2005 §6) | Identical | 直接互认 (Direct mutual recognition) | LOW |
| Optical scanning method | Not included (GB/T 8806-2008) | Included in ISO 3126:2021 §7 | Different test method (no direct comparison) | 附加测试后互认 (Mutual recognition after additional testing) | MEDIUM |
| Conditioning atmosphere | 23°C ± 2°C, 50% ± 10% RH (GB/T 8806-2008 §4) | 23°C ± 2°C, 50% ± 10% RH (ISO 3126:2005 §4) | Identical | 直接互认 (Direct mutual recognition) | LOW |
KEY DIFFERENCES SUMMARY
- Edition currency: GB/T 8806-2008 is IDT to ISO 3126:2005; ISO 3126:2021 is current international edition — 不可互认 (Not mutually recognised) for 2021-specific methods. Procurement impact: MEDIUM.
- Optical scanning: ISO 3126:2021 adds optical scanning method; GB/T 8806-2008 does not — 附加测试后互认 (Mutual recognition after additional testing). Procurement impact: MEDIUM.
REGULATORY LINKAGE TABLE (法规联动)
| Compliance Scenario | Chinese Regulatory Basis | International Regulatory Basis |
|---|---|---|
| Mandatory product certification | N/A (GB/T is recommended) | N/A (test method standard) |
| Engineering acceptance inspection | N/A (test method standard) | N/A (test method standard) |
| Import/export compliance | N/A (test method standard) | N/A (test method standard) |
| Designer/engineer obligation | N/A for product standard comparison | N/A for product standard comparison |
AUDIT FLAG RESOLUTION
- ✅ RESOLVED: GB/T 8806-2008 is IDT to ISO 3126:2005 (confirmed from official foreword: "等同采用"). Answer A incorrectly stated MOD; Answer B correctly stated IDT.
- ✅ RESOLVED: ISO 3126:2021 is current edition (confirmed from ISO website). Answer B correctly noted supersession; Answer A incorrectly stated 2005 as current.
- ✅ FALSE POSITIVE (domain flag): GB/T 8806-2008 — flagged as potential misapplication for pipe dimension measurement, but usage is valid because it is the dedicated test method standard for this parameter.
PROCUREMENT VERDICT
- Accept GB/T 8806-2008 test reports as equivalent to ISO 3126:2005.
- If ISO 3126:2021 compliance required, request additional optical scanning test per ISO 3126:2021 §7.
- Verify conditioning atmosphere (23°C ± 2°C, 50% ± 10% RH) matches both standards.
- Confirm measurement accuracy (±0.02 mm for ≤10 mm) in supplier test report.
REFERENCE DOCUMENT CHECKLIST (配套调阅清单)
- GB/T 8806-2008 §4 — conditioning atmosphere
- GB/T 8806-2008 §5 — measurement method
- ISO 3126:2021 §7 — optical scanning method (if required)
FIELD INSPECTION CHECKLIST
- Verify micrometer/caliper calibration certificate (accuracy ±0.02 mm)
- Confirm conditioning chamber temperature/humidity logs (23°C ± 2°C, 50% ± 10% RH)
- Check test report includes measurement points per GB/T 8806-2008 §6
- If optical scanning required, verify equipment meets ISO 3126:2021 §7
CONFIDENCE RATING
🟢 HIGH CONFIDENCE — data verified across two independent AI sources, all numeric values have clause references, official standard status confirmed from std.samr.gov.cn.
Technical comparison report — CN Quality Check Standards Tool. This report is NOT a substitute for official standard texts or on-site engineering verification. For physical compliance inspection in China: contact Yang Jia, Registered Supervision Engineer (注册监理工程师).
Need on-site compliance verification in China?
This report is an AI-assisted technical reference. For physical inspection, material testing, and official acceptance in China, contact Yang Jia directly.
Request an Inspection →