Pre-Shipment Inspection (PSI)
Quantity, packing, shipping marks, AQL sampling (ISO 2859-1 / ANSI/ASQ Z1.4), visual workmanship, dimensions vs drawing, nameplate / marking check, document review.
Third-party QC
Industrial valves
Machinery
Zhejiang, China
Valve & Machinery Inspection in Ningbo / Zhejiang
Independent eyes on the factory floor. ValveWitness Inspection witnesses API 598 pressure tests and carries out on-site pre-shipment inspection, factory audits and loading supervision for overseas buyers sourcing industrial valves and machinery from Ningbo and the Zhejiang valve cluster.
Request an inspection See pricingServices
Fact-based on-site checks with photo evidence and a clear PASS / FAIL / PENDING conclusion in English.
During Production (DUPRO)
Mid-production check on workmanship, in-process dimensions and early defect trends before the full lot is finished — useful when lead time is tight.
API 598 Pressure-Test Witnessing
Witness shell, seat and backseat tests to the standard named in your PO (API 598, API 6D, ISO 5208 or EN 12266-1). Hold periods recorded on video where permitted.
Factory Audit
Practical supplier check: production capability, basic quality system, calibration status of gauges, and whether the factory can meet your PO — not a full ISO certification audit.
Loading Supervision
Container / truck loading watch: count, packing condition, container cleanliness, seal number photos and loading sequence records.
Optional add-ons
- Coating DFT measurement (own gauge)
- PMI witness (factory XRF) or own instrument if available
- Operation / functional check per your checklist
Coverage area
Based in Ningbo High-tech Zone. Travel outside Ningbo is quoted before acceptance.
Ningbo
Primary coverage — same-day or next-day where schedule allows.
Wenzhou / Oubei
Valve manufacturing hub; common for ball, gate, globe and check valves.
Taizhou
Machinery and valve suppliers in the coastal corridor.
Yuhuan
Valve and pipeline fittings cluster; day-trip or overnight as needed.
Why ValveWitness
Independent eyes on the factory floor — we witness the pressure test, not just the paperwork.
Local to the valve belt
We work from Ningbo and regularly cover Wenzhou/Oubei, Taizhou and Yuhuan — the heart of China’s industrial valve export base.
Pressure-test literacy
Our checklists follow public standards such as API 598 and ISO 2859-1. Every report gets an internal technical review before issue.
Evidence first
Time- and GPS-watermarked photos, original image pack shared with you, and a short English report you can act on within about 24 hours.
Independence
We report facts only. We do not accept gifts or “arrangements” from factories.
Honesty note: ValveWitness Inspection is a small independent service. We do not claim third-party accreditation logos, invented client lists, or inflated years of company history. Scope and limitations are written into every quotation.
Transparent pricing
USD reference rates for Ningbo-area work. Final quote depends on scope, valve count and travel.
| Service | Indicative price | Includes |
|---|---|---|
| Standard PSI — 1 man-day (Ningbo area) | from USD 220–260 / man-day | On-site inspection, English report, photo pack, local Ningbo travel |
| Pressure-test witnessing added to PSI | + USD 60–100 / day | Depends on number of valves and hold duration |
| Pressure-test witness only (half day) | USD 150–180 | Minimum charge |
| Factory audit / loading supervision | Quoted per job | Usually similar to a PSI man-day for a standard visit |
| Travel outside Ningbo (e.g. Wenzhou, Taizhou, Yuhuan) | Actual cost or fixed surcharge | Confirmed in writing before the job |
Coating DFT is included when we bring a gauge. PMI is quoted separately or witnessed on the factory’s calibrated XRF. Re-inspection is charged as a new man-day. 24-hour cancellation rule applies unless otherwise agreed.
Sample report
Reports follow a fixed English template: scope, AQL plan, findings by defect class, pressure-test witness log (when ordered), photo index and a clear conclusion.
Ask us for a redacted sample PSI report (EXAMPLE data only). Templates are written from public standards (API 598, ISO 2859-1, MSS SP-25, etc.) — not copied from any employer’s proprietary forms.
How it works
Four steps from inquiry to report.
- Send your PO / spec and preferred date. We confirm scope, man-days and price within one working day.
- We book the factory visit. You receive the inspector name, arrival window and what the factory must prepare (drawings, gauges, pressure-test setup).
- On-site inspection. Sampling, measurements, photos and — if ordered — witnessed pressure tests per your standard.
- English report. Normally within 24 hours after the visit, after internal technical review. Original photos included.
Contact
Tell us the valve type, quantity, factory city and inspection date.
Base: Ningbo High-tech Zone, Zhejiang, China. We reply in English by email during China business hours, and as soon as practical on weekends when a job is active.