How to Choose an AAC Plant Manufacturer in China

To choose an AAC plant manufacturer in China, send two or three makers the same written brief and compare their answers on five points. First, the process route and cutting machine. Second, whether the claimed output matches molds, cutting time and autoclaves. Third, the autoclave pressure vessel licence and documents. Fourth, a test run and inspection before shipment. Fifth, who commissions the line. Compare price only after these match.

Searching for “AAC block machine manufacturer in China” brings up long directory lists and many company websites that say much the same thing. This guide is for the buyer who has a shortlist and needs to tell the proposals apart. It covers what to ask, what to look at in the workshop, what a factory test run can and cannot prove, and which autoclave documents to settle before you sign. It ends with how we run the comparison for buyers.

What You Are Actually Buying from an AAC Plant Manufacturer

An AAC block plant is not one machine. It is a chain of equipment that has to work as one line:

• Raw material preparation: jaw crusher, bucket elevator, wet ball mill, slurry tanks and pumps.
• Batching and pouring: silos, screw conveyors, weighing scales, slurry weighing tank, aluminum mixer, pouring mixer, pouring car.
• Molds and side plates in circulation.
• Pre-curing room and mold conveying.
• Tilting crane, cutting car, longitudinal and cross cutters, and waste slurry return.
• Crust-removal crane, semi-finished spreader, autoclave cars, transfer car, winch.
• Autoclaves and steam boiler.
• Separating machine and packing line.
• Controls, electrical cabinets, compressed air, dust collection.

A line supplier usually builds some of these in its own workshop and buys the rest. So the first question for every manufacturer is: which items do you make yourselves, and who makes the rest? The answer tells you where to look during the factory audit, and which documents come from a sub-supplier, the autoclaves above all.

Comparison Checklist for AAC Block Machine Manufacturers in China

Send the same brief to every supplier. Include output, block sizes, density grades, product standard, raw materials, boiler fuel, power supply and site dimensions. Then score the answers side by side:

Proposals rarely differ in their headline. They differ in the rows marked “as required” or left blank. Those are the rows to push on.

Check the Capacity Claim Against the Equipment

Every manufacturer can write “100,000 m³ per year” on a proposal. Ask each one to fill in the arithmetic behind it:

1. Volume per mold. On our reference line the net cake is 4200 × 1200 × 600 mm, or 3.024 m³.
2. Molds per day = annual output ÷ operating days ÷ volume per mold. At 330 days of continuous three-shift operation, 100,000 m³ needs about 100 molds a day; the six autoclaves of our reference line cure about 105.
3. Cutting hours per day = molds per day × cutting time per mold. At about 6 minutes, 105 molds take about 10.5 hours.
4. Autoclave loads per day = molds per day ÷ molds per autoclave. Compare this with the number of autoclaves × 24 h ÷ cycle time. On our reference design an autoclave holds 4 cars and 8 molds, and the cycle takes about 11 hours, with 7 hours at full pressure.
5. Molds in circulation, enough to cover pouring, pre-curing at 2–4 hours, cutting and return.
6. Steam for autoclaves cycling one after another.

If the operating days, cycle time and autoclave count in one proposal do not produce the output on its cover page, ask the supplier to correct it in writing. Then compare the corrected versions. Our AAC block manufacturing process flow chart explains each step behind these figures.

Factory Audit: What to See in the Workshop

A visit is worth most when you know what to look at. Before you go, ask for the equipment list split into made in-house and bought in.

1. The cutting machine under assembly. Look at frame rigidity, the wire tensioning system and how the cutting car is guided. Cutting accuracy is built into the frame. Our AAC block cutting machine article covers the design points.
2. Molds and side plates. Check the welding, the flatness of side plates and how the mold frame locks. A side plate that warps gives blocks that are out of tolerance at the bottom.
3. Cranes and spreaders. The tilting and crust-removal spreaders grip the soft cake. Look at how the gripping force is controlled.
4. Welding and machining. Look for welder qualification records, machining capacity for large parts, and incoming material inspection.
5. The autoclave maker. If the autoclaves are made elsewhere, visit that workshop too, or at least see its pressure vessel licence and records for vessels of your size.
6. A running line. Ask to see a line of the same process route running in China, and spend time at the cutting machine and in front of the autoclaves. A running plant shows more than a sales hall.
7. Quality records. Ask for a sample inspection record from a recent export order, with customer details removed.

Test Run and Pre-Shipment Inspection

Before shipment, the equipment can be tested at the factory. Some things only show on site. It helps to agree which is which in the contract.

For every line we source: “Every shipment comes with a full pre-shipment inspection report — test-run records, functional and dimensional checks, photos and video — before the equipment leaves the factory.” If you want an independent check as well, third-party inspection can be arranged on request, at the buyer’s cost.

At inspection, also check the export packing. Electrical cabinets and control parts need moisture protection. Wires, small parts and spare parts should be packed and listed by case, and heavy items should have lifting points marked. A complete, case-numbered packing list makes installation faster, because nothing has to be searched for on site.

Autoclave Pressure Vessel Certificates

The autoclaves are the only pressure vessels in most AAC plants, and the item buyers most often leave too late.

Chinese certification. In China, stationary pressure vessels are regulated by TSG 21-2016. The manufacturer must hold a special equipment manufacturing licence and work within its approved scope under a quality assurance system. Manufacture is subject to supervisory inspection by an inspection body, which does not replace the maker’s own inspection and testing (TSG 21-2016). In practice, ask for the maker’s licence and, for your vessels, the product quality documents, the supervisory inspection certificate and the nameplate data. The autoclaves we source are delivered with Chinese GB/TSG pressure vessel certification.

Your country’s rules. Find out before contract what your country requires to register and operate a pressure vessel. Requirements differ, so ask the registering authority whether the Chinese documents plus local inspection are enough or whether a specific code is required. In the EU, pressure equipment falls under the Pressure Equipment Directive 2014/68/EU. Where ASME is required, the ASME Certification Mark with the U designator applies to pressure vessels built under Section VIII, Division 1, and certificate holders can be looked up in ASME’s directory (ASME). Third-party inspection or ASME U-stamp documentation can be arranged on request, at the buyer’s cost. Decide this before the vessels are built, not after.

Door safety. Autoclave doors are quick-opening closures. Check that the safety interlock prevents pressurizing until the door is fully locked and prevents opening while there is pressure inside. Make sure the interlock is covered in the inspection record. Our autoclave for an AAC plant article covers sizing and the curing cycle.

Commissioning, Warranty and How We Compare Manufacturers

Commissioning. Ask who will come, how many people, and which disciplines. Mechanical installation alone is not enough. Someone has to tune the mix, pre-curing and autoclave cycle on your raw materials. On lines we supply, 3–4 engineers covering process, mechanical, electrical and thermal work supervise installation, autoclave commissioning and trial production. Their travel and accommodation are at the buyer’s cost. Operators and maintenance staff are trained during installation and trial production.

Warranty. Ask when it starts and who answers the phone. Ours: “12-month equipment warranty from the date of commissioning, with a named responsible contact.”

How we work. YuxingCorp is a Singapore company that supplies building-material production lines built by vetted manufacturers in China. We are not the manufacturer. For an AAC project we:

1. Turn your requirements into one brief: output, block sizes, density grades, standard, raw materials, fuel, power and site.
2. Test your raw materials (30–50 kg samples) so the formula and configuration rest on results.
3. Compare configurations from several manufacturers against that brief, row by row, using the checklist above. “A written sourcing report within 48 hours of a complete requirement brief.”
4. Inspect before shipment and issue the pre-shipment inspection report.
5. Prepare the export documents, coordinate shipping, and support installation and commissioning.

Import customs clearance, duties and local registration remain the buyer’s responsibility.

FAQ

How many AAC plant manufacturers in China should I compare?

Two or three serious proposals are usually enough, if they answer the same written brief. More than that adds work without adding clarity. What matters is that each proposal states its process route, cutting time per mold, autoclave count and size, and scope of supply, so the differences are visible before price is discussed.

Is in-air tilting better than ground tilting for AAC cutting?

With in-air tilting, the cake and mold are turned 90° in the air and the cake stands on its side plate from then until it leaves the autoclave, so the soft cake is never set down on its side on the ground. Whichever route a supplier proposes, ask it to show the cake’s position and support at every step, and check cutting tolerance against your product standard.

What documents should come with the autoclaves?

At minimum, the Chinese pressure vessel documents: the maker’s licence, product quality documents, the supervisory inspection certificate and nameplate data under TSG 21-2016. Your country may also require third-party inspection, ASME documentation or registration with a local authority. Agree the full list in the contract, before the vessels are manufactured.

Can I check the equipment before it leaves China?

Yes. Cutting machines can run empty, molds and side plates can be measured, cranes tested, electrical cabinets checked and autoclave pressure test records reviewed at the factory. Cutting real cake and running loaded autoclave cycles can only be proven at commissioning. Agree in the contract which checks happen at the factory and which on site.

Should I buy directly from a manufacturer or through a sourcing company?

Either can work. Buying directly suits a buyer who can run the comparison, factory audit, inspection and document checks with its own engineers. A sourcing company takes on that work. We compare several manufacturers against one brief, inspect before shipment, prepare export documents and support commissioning, but we are not the manufacturer. We respond within one business day.

Planning an AAC Block Plant?

See the reference configuration by capacity on our AAC block production line page. For the full planning sequence, from requirement brief to commissioning, read the AAC block plant setup guide.

Sources

• TSG 21-2016 Supervision Regulation on Safety Technology for Stationary Pressure Vessel (standard listing): https://www.chinesestandard.net/PDF.aspx/TSG21-2016
• ASME, Boiler and Pressure Vessel Certification: https://www.asme.org/certification-accreditation/boiler-and-pressure-vessel-certification
• Directive 2014/68/EU on pressure equipment (EUR-Lex): https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32014L0068
• Dubai Municipality, DM-DCLD-RD-DP21-2173 (IC) Specific rule for certification of autoclaved aerated concrete masonry units, Rev. 09 (2024): https://www.dm.gov.ae/wp-content/uploads/2024/09/DM-DCLD-RD-DP21-2173-IC-TG-01-Part-3-AAC-R9.pdf