| Product requirements for pipes | GB/T 15558.1-2015, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 1: Pipes | Check the standard edition specified in the contract, pipe dimensions, material designation, marking, and applicable test documentation. | This Chinese national standard covers PE pipes for gaseous-fuel supply applications. |
| Product requirements for fittings | GB/T 15558.2-2015, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 2: Fittings | Confirm that fittings are designed for the intended pipe system and that compatibility, joining method, and traceability are documented. | Pipe and fitting compliance are separate checks; compliant pipes alone do not establish system compliance. |
| Valves in PE gas systems | GB/T 15558.3-2008, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 3: Valves | Check the applicable edition and project requirements for PE valves, including product identification and supporting test records. | Valves are addressed separately from pipes and fittings in the GB/T 15558 series. |
| International product framework | ISO 4437 series, covering PE piping systems for the supply of gaseous fuels | Ask which edition and parts are claimed, and compare them with the destination market’s regulations and project specification. | ISO standards can support international procurement, but they do not automatically replace applicable Chinese or importing-country requirements. |
| Material and pressure classification | Product markings and technical documentation, including PE compound designation, SDR, nominal diameter, and stated pressure limits | Match the marked pipe characteristics to the design pressure, operating conditions, and engineering specification; request material and batch records. | Selection depends on the complete system design and applicable code, not on a single product label. |
| Quality-management evidence | ISO 9001 quality-management-system certificate, where held | Verify the certificate’s validity, issuing body, certified site, and scope; confirm that the scope covers relevant manufacturing activities. | ISO 9001 concerns a management system. It is not, by itself, proof that a particular pipe model meets product requirements. |
| Testing and inspection | Test reports from a competent laboratory; CNAS accreditation may be relevant to the laboratory’s accreditation status | Check the laboratory, test methods, sample identification, report date, and whether the reported tests match the product and standard claimed. | Laboratory accreditation applies to defined activities and scopes; it should not be treated as a blanket product approval. |
| Product certification claims | Any voluntary product certificate or third-party conformity document claimed by the supplier | Verify the certificate with its issuer, including product scope, model coverage, validity, and surveillance status. | Do not assume that a certificate is mandatory or applicable to every PE gas pipe; confirm requirements with the project owner and relevant authorities. |
| Manufacturer comparison | Documented production capability, quality controls, traceability, testing facilities, delivery record, and project references | Compare evidence against the project specification and conduct supplier qualification; request anonymized or verifiable records where appropriate. | A defensible “top manufacturer” assessment depends on the market, application, and independently verifiable criteria rather than an unsupported ranking. |