Home › Guides › How to verify a Chinese valve supplier

How to verify a Chinese valve supplier before the first order

Five checks you can run before a trial order — most of them from your desk — and how to set inspection hold points so the first shipment tells you what you need to know.

General Inspection2026-11-148 min read

supplier verificationgsxt.gov.cnfactory auditMTC

Short answer: To verify a Chinese valve supplier, check its business licence and scope on the official gsxt.gov.cn register, confirm whether it makes or only trades valves, see its test bench and calibrated gauges on a live video call, test heat-number traceability against an MTC, then place a trial order with DUPRO and PSI hold points.

By Kevin Lyu (吕中国), ValveWitness Inspection, Ningbo · Published 2026-11-14

Check 1 — The business licence and scope on gsxt.gov.cn

China’s official company register is the National Enterprise Credit Information Publicity System at gsxt.gov.cn. Ask the supplier for a scan of its business licence (营业执照), then look it up yourself. If the Chinese-language site is a barrier, we can run the lookup and translate the result as part of a factory audit.

Field on gsxt.gov.cn	What to check
Unified social credit code (统一社会信用代码)	Matches the code on the licence copy and on the contract and invoices.
Company name (Chinese)	Exactly the name on your contract; English names are not registered.
Business scope (经营范围)	Look for manufacturing (制造 / 生产) of valves, not only sales (销售) or import/export.
Registered address (住所)	Compare with the factory address on the video call and the shipping documents.
Date of establishment and status	Status should be “存续” or “在业” (active); check how long the company has existed.
Abnormal operations and penalties	Entries on the abnormal operations list (经营异常名录) or administrative penalties are worth asking about.

Check 2 — Trading company or real workshop?

Scope: a licence that lists only sales or import/export means the valves are made elsewhere.
Specific answers: a maker can tell you its casting source, machining capacity, test bench sizes and lead time per size without “checking with the factory”.
Product range: a catalogue of every valve type, every material and every standard is typical of a trader.
Address: the registered address, the video-call location and the loading address should make sense together.
Ask directly: many good suppliers are traders. The point is to know which factory to inspect.

Check 3 — Test bench and gauges on a live video call

Ask to see the test bench live, not a pre-recorded video. Ask for a valve of your size and class on the bench.
Ask the operator to show the pressure gauge face, the gauge ID label and the calibration certificate with its due date.
Check the bench can reach the shell test pressure your largest valve needs, and that the gauge range suits it.
Ask how they run a low-pressure air seat test, and where the leak is observed.
Ask for one recent test record — and read it with the six red flags in mind.

Check 4 — Heat-number and MTC traceability

Ask for an EN 10204 3.1 certificate for a recent order, with the matching photo of the cast or stamped heat number on a body.
The heat number on the body, the certificate and the test record should be the same.
Check the material grade, the standard it is certified to, and who signed it — see EN 10204 3.1 vs 3.2 and PMI.
If the supplier claims a third-party licence (for example an API monogram), verify it on the issuing body’s own public register rather than accepting a PDF.

Check 5 — Trial-order hold points and a factory audit

Factory audit before or alongside the trial order: capability, equipment, gauge calibration, how certificates and heat numbers are handled.
DUPRO when bodies are machined and still unpainted.
Pressure test witness as a hold point, to the standard and edition in the PO.
PSI when 100% finished and at least 80% packed, with a written AQL plan.

Desk checks before you spend anything

Licence, scope and status on gsxt.gov.cn.
A live video of the bench, gauge ID and calibration certificate.
A recent MTC with a matching heat-number photo.

Then book a factory audit or a DUPRO on the trial order.

Questions buyers ask

Is a trading company always a bad choice?

No. A good trader can manage several factories well. What matters is knowing who actually makes and tests your valves, so inspection and hold points are set at the right site.

Can I check a Chinese business licence myself?

Yes, on the official gsxt.gov.cn system, which is in Chinese. Search by the full Chinese company name or the 18-character unified social credit code printed on the licence.

Does a factory audit approve the factory?

No. An audit reports what was seen on the day — capability, equipment, basic QC. It does not certify the factory or approve any lot of product.

Sources

National Enterprise Credit Information Publicity System (国家企业信用信息公示系统) — gsxt.gov.cn (official, Chinese-language)
EN 10204, Metallic products — Types of inspection documents — BSI
API 598, Valve Inspection and Testing — API publications store

We report facts from the samples inspected. Standards named in these guides are public standards we work to, not certifications or accreditations we hold. We do not issue product certificates or accreditation marks. Test pressures, durations, leakage rates and acceptance numbers must be read from the licensed edition named in your purchase order; we do not reproduce copyrighted tables from the standards.

Need an inspector at a Zhejiang factory?

Send your PO or specification, the factory city and the date. We confirm scope and price within one working day.

Request an inspection WhatsApp +86 131 2757 0627