Seal-free chemical reactors and pressure vessels — engineered, built, and shipped from China since 2004. One promise: what we quote is what you receive.
WEIHAI ZHENGWEI MACHINERY CO.,LTD was founded in 2004. For over 20 years we have built a complete product range around one core technology — magnetic coupling (seal-free) agitator drives — serving the chemical, pharmaceutical, food, dyeing, materials, and biochemical industries.
Our facility in Zaobu Industrial Park, Gushan, Weihai (Shandong Province) covers over 20,000 square meters of production space with CNC rolling machines, automated welding equipment, and a full quality inspection lab. We are a licensed Class I & II pressure vessel manufacturer (license obtained in 2013), and ISO 9001 certified.
Some suppliers try to be everything to everyone — valves, pumps, instruments, piping, reactors. We chose to go deep instead of wide. Our team knows reactors. We know what happens inside them, what goes wrong, and how to prevent it. That knowledge shows up in every unit we build.
Our Core Technology
Conventional reactors transmit torque through the vessel wall with a dynamic shaft seal (packing or mechanical seal) — a wear item, and a potential leak path. Our magnetic coupling drive transfers torque across the vessel wall with no shaft penetration, no dynamic seal, and no leakage path. That is why customers in harsh-duty processes specify magnetic-coupled chemical reactors.
Safe operation in hydrogenation and other high-temperature, high-pressure flammable services — with no leak path for the medium to escape through.
Reliable service with highly toxic or fine-dust chemicals at high temperature and pressure. Zero seal-related emissions.
No packing to replace, no mechanical seal to maintain. Fewer shutdowns, lower lifetime cost for your plant.
Product Range
Chemical reactors, stirred reactors, and pressure vessels — from laboratory scale to full production lines, in carbon steel, stainless, nickel alloys, and titanium.
Jacketed and coil-cooled stirred reactors, including multi-layer coil designs for exothermic hydrogenation up to 10,000 L.
High-pressure hydrogenation reactors with explosion-proof drives, multi-layer cooling coils, and hydrogen-absorbing agitators.
Nickel (N6), Monel 400, Inconel 600/625, Hastelloy C-276/B-2 — plus titanium-clad and pure titanium (TA1/TA2) vessels, including conical-bottom industrial units.
Small-scale reaction equipment for R&D, process development, and scale-up verification — the same seal-free technology at lab scale.
Storage tanks, high-pressure vessels, and autoclaves — for example, a 15 m³ pressure tank designed and tested at 2.0 MPa / 100 °C.
Polyester resin production lines, alcohol distillation systems, shale-oil hydrogenation systems, and high-pressure chemical piping — one factory, one drawing set.
Quality & Certifications
ISO 9001 certified. Licensed Class I & II pressure vessel manufacturer since 2013. ASME product certification available on request. Every claim below is enforced on the production floor — not just in the manual.
Every steel plate, every forging, every flange has a mill test certificate. We verify the grade, the chemistry, the mechanical properties. If a certificate is missing or doesn't match, the material doesn't enter production. Period.
We don't say "NDT performed" and move on. Every weld joint that requires inspection is inspected. RT, UT, PT, MT — whatever the code and your service conditions require. Reports are generated, numbered, and filed with your documentation package.
Every pressure vessel is hydrostatically tested at 1.5× design pressure. No exemptions. No shortcuts. This isn't expensive — it's insurance. For you and for us.
Zero leakage is not a marketing claim — it's our standard. Packing seals leak. Mechanical seals wear. Magnetic coupling seals don't. If your medium is toxic, flammable, or valuable, this matters. Every reactor we build has a magnetic coupling seal.
No "substantially equivalent" substitutions. No "we used what was available." What's on the approved drawing is what's in the vessel. If a change is needed, we flag it, get your approval, and update the drawing. You should always know exactly what you're getting.
A reactor that arrives damaged is a reactor that causes delays. We package for sea freight. Proper lashing. Moisture protection. Corner guards. We've seen what happens when suppliers cut corners on packaging — don't let that be your problem.
Why Us
We won't load your reactor with unnecessary grades or testing — but safety valves, relief devices, and instrumentation are never compromised. What you pay for is right-sized: economical, not cheap.
Before quoting, we review your medium, temperature, pressure, and agitation scheme — material selection, heat-transfer area, seal type, nozzle layout. Problems caught at the drawing stage cost you nothing; caught after commissioning, they cost months.
Magnetic coupling removes the most common failure mode in reaction equipment — the shaft seal — so your reactor keeps running where conventional designs start leaking.
Reactor, piping, and support equipment from one factory. FOB / CIF terms, export-grade packing, and a complete documentation pack with every unit — MTCs, NDT reports, test reports, certificate of conformity.
Project Track Record
A selection of recent deliveries:
Tell us your process conditions and we'll advise on material selection, heat transfer design, agitation, and sealing. No obligation.