Third-Party Inspection Process for Plug Valves

In order to help you understand the complete process of the third-party inspection of the plug valve, the following is a specific description of the steps we coordinate and conduct on-site witnessing inspections with BV, DNV or SGS. We have four stages of the whole process.



Stage 1: Pre-Inspection Preparation
What we complete

50. Prepare the Inspection and Test Plan (ITP) based on project specifications, clearly mark the key points (H) and the witnessing points (W).
50. Compile material certificates, including EN 10204 Type 3.2 certificates (third-party endorsed) for body, plug and other critical components
50. Prepare welding procedure qualification, welder qualifications, NDT personnel certificates, and calibration certificates for test equipment
50. Complete internal pre-testing to ensure product readiness

What we need from you or the inspection body

50. Confirmation of the ITP with written approval from BV/DNV/SGS
50. Clarification on whether additional tests are required, such as fire test (API 607) or fugitive emission test (ISO 15848)
50. Notification of inspector's arrival date and contact details

Stage 2: On-Site Arrival & Document Review
On the first day of inspection

50. Verify completeness and validity of ITP, material certificates, test procedures, etc.
50. Randomly select plug valves and check compliance with drawings and purchase specifications
50. Verify that calibration certificates for test equipment are within validity period

Potential issues to note

50. Material certificate not Type 3.2 → Replacement or supplementary documentation required
50. Calibration certificate expired → Re-calibration required before testing can proceed

Stage 3: On-Site Witness Testing
The inspector will witness the following tests (as specified in the ITP):


After testing

50. Inspectors signs original records if data is acceptable
50. If non-conformities is found, the inspector records them, suspends witnessing until corrections are made and re-inspection is requested

Stage 4: Inspection Report & Release
After inspection is completed

50. We prepare complete test reports and photo/video records
50. BV/DNV/SGS issues the third-party inspection report or release note (signed and stamped)
50. The inspection report is delivered to you together with the product

Typical time required

50. Document preparation & pre-review: 5–10 working days
50. On-site witnessing: 1–3 days (depending on quantity and test items)
50. Report issuance: 3–7 working days

Process Flow
Submit ITP & documents → Agency review → Inspector on site → Document re-check → Visual & dimensional inspection → PMI → Pressure test → Functional test → (if applicable) Fire / fugitive emission test → Inspector confirmation → Report issuance → Release for shipment

If you have specific concerns about any stage or wish to adjust the witnessing method (e.g., remote video witnessing only), please let us know in advance. We will assist in coordinating with the inspection body.
If you have any other question or discuss more, please contact ZZJG PLUG VALVE.

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