Accuflow
Mass Flow Controllers
Thermal and differential-pressure mass flow controllers and meters, and digital pressure controllers, from a Beijing company registered in 2015 to manufacture instruments and to export. High-temperature, 40 MPa and metal-seal versions are published. The live registry read, production site and certificates are the open checks.
Two measuring principles, and a pressure-control family.
Thermal Mass Flow Controllers & Meters
The ACU10FA (analogue), ACU10FD (digital) and ACU20FD (high-accuracy) lines measure mass flow directly with a heated sensor and bypass, with an integrated proportional valve and PID on the controller versions. The ACU20FD is published at ±0.5% F.S. accuracy, ±0.2% F.S. repeatability and <0.2 s response, with metal-seal and high-pressure variants. Note that accuracy is stated as a share of full scale, not of reading — ask what it is at your lowest setpoint.
Differential-Pressure (Laminar) Mass Flow Controllers
The ACU10FC, ACU20FC and ACU30FC measure across a laminar element and correct for temperature and pressure. The ACU20FC manual states that when a gas conversion factor is applied there is no additional specific-heat error, so measuring a gas other than the calibration gas does not degrade accuracy — the usual weakness of thermal devices. That is a company-published claim; ask for comparative test data on your gases.
High-Temperature & Steam Flow Controllers
The ACU10FCH and ACU20FCH are sold as steam-and-gas two-in-one controllers with a 50:1 turndown, and the ACU20FDH is a high-temperature thermal type rated for media up to 150 °C. The ACU20FDH manual is titled “Coriolis Mass Flow Controllers & Meters” although its body describes a thermal instrument — confirm which product you are quoting.
Low-Pressure-Drop Flow Controllers
The ACU10FDR and ACU20FDR are built for lines where the controller may not take much pressure away, with a stated working pressure drop below 0.01 MPa on the ACU20 series. Useful where upstream pressure is low or where several controllers sit in series.
Digital Pressure Controllers
The ACU10P, ACU20P single-valve, ACU20PCD dual-valve and ACU20PH high-temperature controllers, plus an ACU20P variant rated to 40 MPa. Applications named in the manuals include MOCVD vapour-pressure control, gas and liquid chromatography, extrusion gas protection and autoclave or reactor pressure control. Meter-only versions (ACU20PM) are also listed.
Interfaces & Connections
Manuals list RS232/RS485 with Modbus RTU, Profibus, EtherCAT, Profinet and Foundation Fieldbus, alongside 0–5 V and 4–20 mA analogue I/O. Connections include barb, push-in, VCR and flange; seals in FKM, neoprene, nitrile, perfluoroelastomer or metal. Protocol lists are not the same as protocol conformance certificates — ask which interfaces have passed their organisation’s conformance test.
What the registry confirms, and what stays open.
Registered to Make and to Export
The licence’s registered scope includes, in its own words, 智能仪器仪表制造 (smart instrument manufacture), 实验分析仪器制造 (laboratory analytical instrument manufacture), 工业自动控制系统装置制造 (industrial automatic control equipment manufacture) and 普通阀门和旋塞制造（不含特种设备制造） (ordinary valves and cocks, excluding special equipment), and also 货物进出口；技术进出口 (import and export of goods and technology). So the entity is registered both to manufacture this kind of product and to be the exporter of record.
Three Addresses on Record
The licence’s registered address is a second-floor unit, A-1429, in Building 3 of a compound on Shixing Street, Shijingshan District. The English website gives an office in a commercial tower on Wangjing East Road, Chaoyang District. The Chinese website says R&D and production are in the Zhongguancun Science Park, without an address. All three can be true of a company that registers in one place and works in another, but none of them reads as a production floor. Ask where the controllers are assembled and calibrated, and whether that line can be seen.
Brand Story and Registry Read Differently
The Chinese website introduces “ACCU (Chinese name 精量)” as a well-known process-instrument and automation supplier whose products have sold at home and abroad for years, with its “Asia-Pacific” R&D and production site in Beijing. That reads like the China arm of an overseas brand. The licence shows a domestic limited liability company held by individuals, registered in 2015. If there is an overseas parent, ask for its legal name, country and relationship to this entity; if there is not, the site wording is the thing to correct.
Explosion-Proof Claim Without a Certificate
The ACU20 manuals repeatedly describe an IP67 enclosure and IICT4 intrinsic safety. Across all nineteen manuals there is no certificate number — no Chinese explosion-proof certificate, no ATEX, no IECEx. Intrinsic safety is a safety certification, not a design description, and a hazardous-area buyer cannot install without the certificate for that exact model. Not claimed on this page.
Export-Control Classification Not Yet Done
A mass flow controller contains a control valve, and the manuals name semiconductor, MOCVD and chemical uses and offer metal-seal versions. Under the dual-use regimes implemented in the EU control list and the US EAR (ECCN 2B350.g), valves whose wetted surfaces are made of specified corrosion-resistant materials are controlled, and China applies its own dual-use list. This page draws no conclusion about any model; it records that the classification has not been done and should be before a semiconductor or chemical-grade model ships.
Paperwork to Tidy
An English-site news item states ISO 9001 was obtained on 2022-09-21 and shows a certificate image, but no certificate number or issuing body; on a three-year cycle it is now due for recertification. The Chinese site describes “original R&D patents” for four items that are all named as system software — which reads as software copyright registration rather than patents, and two concern dust and air-pollutant monitoring rather than flow control. None of these is claimed here until the documents are seen.
What was checked — and what the check found.
Nothing on this page is a CMH verification. The business licence was provided and its fields are quoted as printed, and the credit code’s check digit passes; but a licence issued in 2022 does not show today’s registration status, insured headcount or penalty record, and that live registry read has not been done. Product figures come from the company’s own manuals and websites and are labelled as such. When the registry read is done and certificates are seen, this page is updated and the badge follows the record.
An instrument maker, read off its licence, manuals and two websites.
Accuflow is the English trading name of Beijing Accuflow Technology Co., Ltd. (北京精量科技有限公司), registered on 4 December 2015 in Shijingshan District, Beijing, as a limited liability company held by individuals with registered capital of RMB 5 million. Its registered scope includes smart-instrument, analytical-instrument, automatic-control and valve manufacture, and the import and export of goods and technology.
It publishes nineteen product manuals across three families: thermal mass flow controllers and meters, differential-pressure (laminar) flow controllers including high-temperature and steam versions, and digital pressure controllers up to 40 MPa. The manuals give ±0.5% F.S. accuracy and <0.2 s response for the ACU20 series, list six industrial interfaces, and include a gas conversion factor method — with the differential-pressure line described as free of specific-heat error on gas change.
What is not yet on record matters as much. The live registry read has not been done; three different addresses appear across the licence and two websites, none of them clearly a production floor; the Chinese website frames the brand as the Asia-Pacific arm of an established supplier while the licence shows a domestic company; and the explosion-proof, ISO 9001 and fieldbus claims have no certificate numbers. None of that makes the products less real — it makes those the first questions to ask.
Registered in 2015, by the licence on record.
Company registered
Registered on 4 December 2015 in Shijingshan District, Beijing, as a limited liability company held by individuals, with registered capital of RMB 5 million (licence sighted).
Chinese website filed
The Chinese site carries ICP filing 京ICP备17013437号-1.
Licence reissued · ISO 9001 stated
The licence on record was issued on 9 June 2022. An English-site news item dated 29 September 2022 states ISO 9001 was obtained on 21 September 2022; no certificate number or issuer is shown.
Joins CMH
Listed September 2026 with nineteen product manuals and the business licence provided; the live registry read, production site and certificates remain open.
Who these controllers are for.
Analytical & Laboratory Instrument OEMs
A controller that goes inside a chromatograph, gas blender or coating system. Two principles and six interfaces from one supplier make it easier to standardise a platform across models.
Semiconductor Back-End, MOCVD & Solar Lines
The manuals name MOCVD vapour-pressure control and vacuum processes. For these uses ask first for the export-control classification and the seal and wetted-material list of the model.
Chemical, Pharmaceutical & Gas-Blending Systems
Where one instrument sees several gases, the differential-pressure line’s published claim of no specific-heat error on gas change is the point to test against a thermal alternative.
Research Laboratories
Mixed gases, low volumes and frequent changes. Ask for the gas conversion factor table the manuals already contain and for accuracy at low setpoints.
Automation Integrators
EtherCAT, Profinet, Profibus and FF are listed. Ask which have passed conformance testing before designing them into a control architecture.
High-Pressure Process Control
Autoclaves, reactors and extrusion lines. A 40 MPa pressure controller is published; ask for the pressure test certificate and the material of the pressure-bearing parts.
Sourcing guides for this category
What Documents to Request From a Chinese Supplier Before Your First Order
Importing from China: The Compliance Checklist by Market
The 27-Point China Factory Audit Checklist
How to Request a Sample from a Chinese Factory (Without Getting Burned)
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Frequently Asked Questions
What does Accuflow make?
Mass flow controllers and meters for gases and liquids on two measuring principles — thermal (ACU10FA, ACU10FD, ACU20FD, ACU20FDH, ACU20FDR) and differential-pressure (ACU10FC, ACU20FC, ACU30FC, ACU10FCH, ACU20FCH) — and a digital pressure-controller family (ACU10P, ACU20P, ACU20PCD, ACU20PH, including a 40 MPa version). The Chinese website also lists Coriolis flow controllers and controlled evaporator mixers; no manual for those was provided.
Is this listing CMH-verified?
No. The business licence was sighted and the credit code passes its check digit, and the registered scope includes both manufacturing and export. The live registry read — current status, insured staff, any penalties — has not been done, so there is no verified badge.
Thermal or differential-pressure — which should I ask for?
Thermal devices are compact and fast but calibrated for one gas; on another gas a conversion factor is applied and adds error. The company’s ACU20FC differential-pressure manual states that on a gas change it adds no specific-heat error. If your process switches gases, ask for both on the same test and compare.
Can these be used in hazardous areas?
The manuals describe IICT4 intrinsic safety, but no certificate number appears in any of them. Do not specify these for a hazardous area until you have the certificate for the exact model — a Chinese explosion-proof certificate for domestic use, and ATEX or IECEx for most export markets.
What HS code applies?
US customs rulings have classified mass flow controllers built from a thermal sensor, bypass, circuit board and solenoid valve under 9032.89 as flow control instruments, excluding 9026; an earlier ruling had put them under 8481 as valves. Meter-only versions fall under 9026. Classification is decided by customs at entry.
Are there export-control questions?
Possibly, for some models. Controllers with metal seals and corrosion-resistant wetted parts marketed for semiconductor or chemical use should be checked against dual-use valve entries before shipment. The classification has not been done yet; ask for it by model number.
Talk to Accuflow Mass Flow Controllers directly.
Send the gas or gases, flow range, inlet and outlet pressure, temperature, seal material, connection and the interface you need (analogue, Modbus, Profibus, EtherCAT, Profinet or FF). Ask for accuracy at your lowest setpoint, the gas conversion factor, the production address, and — for hazardous-area or semiconductor use — the explosion-proof certificate number and the export-control classification of the model. None of those is on record here.