Short answer: A private-label deal is only as strong as three documents: a CE Declaration of Conformity naming your entity, ISO 1217 test data at your duty point, and a written statement of who owns the controller firmware and tooling. A 3-day factory audit typically costs 1,200–1,500 USD, or about 1.5% of a ten-unit shipment.
By Johnny Wayne, General Manager, AirSpace Machinery Co., Ltd. — 20 years in industrial compressed air systems. Reviewed by our engineering team.
We sit on both sides of this conversation: buyers ask us to build under their brand, distributors ask what to check when they buy elsewhere. In the field the failures repeat — right logo, wrong airend, a controller nobody outside the factory can service, and a CE certificate naming a trading company that no longer answers email. None of it is visible in a quotation.
What does a private-label agreement actually transfer to the buyer?
It transfers a product and a liability, but only what the paperwork says. The brand is yours, the warranty obligation in front of your customer is usually yours, and design authority stays with the factory unless you paid for it.
That split is why verification matters more than price negotiation: a five percent discount costs more than it is worth the first time a controller fails in the field.
Which document proves the machine is CE marked in your name?
The Declaration of Conformity, and it has to name the legal entity that places the product on the market. A CE mark on the nameplate proves nothing; the DoC is what a customs officer, an insurer or a tendering authority asks for.
For a screw compressor it typically cites Machinery Directive 2006/42/EC and EN 1012-1, plus EMC and pressure equipment directives where they apply. Ask for the file, not the logo: technical file, risk assessment and test records should exist for your model.
How do you check whether the airend is yours or a black box?
Ask for the rotor drawing number, machining source and bearing specification in writing. Every factory buys something — rotors, inverters, valves, controllers — and a supplier who says otherwise is telling you about their honesty, not their integration.
What matters is that the answer is stable across two orders and that the service parts are identifiable. If the airend part number changes between the sample and the production run without a notification, assume the specification changed too.
What does ISO 1217 test data tell you that a datasheet does not?
It tells you what the machine delivers at your pressure: ISO 1217:2009 defines how flow and power are measured and how tolerances apply. A catalogue FAD at 7 bar with no test method is a marketing number; a test sheet with standard, ambient conditions and instrument accuracy is a claim you can hold a supplier to.
Two 75 kW units can both be sold as “75 kW, 7 bar” and differ by half a m³/min at the same shaft power.
What does that look like on a worked example?
Take two 75 kW machines at 7 bar. Machine A delivers 12.8 m³/min, which is 5.86 kW per m³/min. Machine B delivers 11.9 m³/min at the same 75 kW, which is 6.30 kW per m³/min.
- Specific power gap: 6.30 − 5.86 = 0.44 kW per m³/min.
- At 11.9 m³/min of delivered air: 0.44 × 11.9 = 5.2 kW of extra input.
- Annual energy: 5.2 kW × 6,000 h = 31,200 kWh.
- Annual cost: 31,200 × 0.08 = 2,500 USD per machine, per 0.08 USD/kWh · 6,000 h/yr.
- Across ten units in the field: 25,000 USD a year your customers pay for a difference that never appears on your invoice.
That is the number to put in front of a private-label buyer: the price gap between the two machines is usually smaller than one year of that difference.
How much does a factory audit cost against the shipment value?
Less than most buyers assume, and far less than the cost of a bad first container. A third-party inspector typically charges 350–500 USD per inspector-day in China, and a competent audit of a compressor factory takes two to three days.
| Item | Figure | Basis |
|---|---|---|
| Order size | 10 × 75 kW units | first private-label run |
| Order value at 9,000 USD FOB | 90,000 USD | use your own quoted price |
| Audit duration | 3 inspector-days | production, test bench, documentation |
| Audit cost at 450 USD/day | 1,350 USD | per third-party inspection day rates |
| Share of order value | 1.5% | audit cost ÷ order value |
| Cost of one failed container | typically 1,200–1,800 USD freight plus 4–6 weeks | re-shipment and lost selling season |
In practice the audit is not there to catch fraud, which is rare. It answers three questions before money moves: can this line hold your tolerance, is the test bench calibrated, and will documents be issued in your name.
Why does the controller decide whether you can service the machine?
Because the controller is where the service business lives. With locked parameters, undocumented fault codes and factory-only firmware updates, every field fault becomes a factory conversation — and your customer measures your response time, not the factory’s.
Ask for the Modbus register map, the parameter access level, the spare controller price and a ten-year availability statement. A controller that speaks Modbus RTU over RS-485 is serviceable by any competent technician; one that does not is a dependency.
What should the contract say about tooling, firmware and warranty split?
4 clauses carry most of the risk: who owns the moulds and the label tooling, who owns the firmware and the right to update it, how warranty costs are split between factory and distributor, and what happens to the private label if the relationship ends.
Put the answers in the agreement, not an email thread. The disputes we see are rarely about machine quality — they are about who pays for a container of failed controllers 18 months after the first order.
What did the numbers look like in a real installation?
Our documented 75 kW PMV VSD installation case study in Vietnam is an iron processing plant in Ho Chi Minh City: 15,000 m², more than 200 employees, 16 hours a day, air costing over 3,200 USD a month, maintenance at 850 USD a month, pressure swinging ±0.5 bar before the change.
That buyer was not a private-label distributor, but the lesson transfers: the decision came down to measured flow, measured pressure stability and a local service path — not the logo on the canopy.
Which product range should a distributor put behind one label?
Wide enough to quote most enquiries without a second supplier, narrow enough that service training stays coherent. Most catalogues settle into five families, and low pressure wins industrial tenders.
| Series | Range | Typical buyer |
|---|---|---|
| PMV variable speed | 10–180 HP | factories with variable demand and an energy target |
| Fixed speed | up to 340 HP (250 kW) | steady-duty plants buying on price per m³/min |
| Two-stage | up to 400 kW | large plants running at 8–10 bar continuously |
| Low pressure | 15–300 HP at 3–5 bar | textile, ceramic, glass and cement plants |
| Oil-free scroll | 2–51 HP, 8/10 bar, Class 0 | dental, laboratory, food and pharma points of use |
A low-pressure air compressor for the textile / ceramic / glass / cement industry is the family that most often decides a distributor’s reputation, because those plants run continuous shifts and measure pressure stability in production losses rather than in bar.
How do you verify the factory is a factory and not a trader?
Three checks settle it in an afternoon. Read the scope line on the ISO 9001:2015 certificate — it should cover manufacture, not trading. Watch the test bench run a machine you did not nominate. Ask for the export documents of two shipments, then call that customer.
AirSpace Machinery Co., Ltd. runs a 4,000 m² facility in Shanghai with 20 years of engineering history, holds ISO 9001:2015 and CE marking, and sells through distributors rather than around them — the arrangement a private-label buyer needs to verify in whichever factory they choose.
Key takeaways
- Three documents decide the deal: a CE Declaration of Conformity in your name, ISO 1217 test data at your duty point, and written ownership of firmware and tooling.
- A half m³/min gap on a 75 kW machine is about 2,500 USD a year per unit at 0.08 USD/kWh · 6,000 h/yr — 25,000 USD across ten units.
- A 3-day factory audit typically costs 1,200–1,500 USD, about 1.5% of a ten-unit order and less than one re-shipped container.
- Serviceability is a controller question, not a spare-parts question: ask for the Modbus map and a ten-year controller availability statement.
Frequently asked questions
Is private-label cheaper than buying a branded compressor?
Usually yes at the same specification, typically 15–30% below a Tier-1 premium brand, because you are not paying the brand’s channel margin. At the same price point it is not cheaper: a lower airend spec costs less to buy and more to run.
Who is legally responsible when a private-label machine fails?
The entity named on the Declaration of Conformity — normally you, as brand owner, in front of your customer. Your recourse against the factory depends on the warranty clause you signed, so write the split before the first order.
Can I use the factory’s CE certificate for my brand?
No. The certificate belongs to the manufacturer and covers the product as they place it on the market. Selling under your own brand normally needs a DoC in your name, based on the factory’s technical file, agreed in writing.
What is the biggest mistake first-time OEM buyers make?
Buying on unit price and sample quality without testing a production unit. The sample is hand-built; the shipment is not. Insist the pre-shipment inspection tests a randomly selected unit from the actual run, at your duty point.
Sources and standards
- ISO 1217:2009 — Displacement compressors — Acceptance tests. Defines how flow and power are measured, and therefore what a FAD claim means.
- ISO 11011:2013 — Compressed air — Energy efficiency — Assessment. The specific-power method behind the kW per m³/min comparison above.
- ISO 8573-1:2010 — air purity classes, relevant when a private-label range includes Class 0 oil-free models.
- EN 1012-1 and Machinery Directive 2006/42/EC — the safety basis for the CE Declaration of Conformity discussed above.
- ISO 9001:2015 — held by AirSpace Machinery Co., Ltd.; certificate scans and declarations are on our downloads page.
- Our published references — the low-pressure compressor series rated 15–300 HP at 3–5 bar, and our note on why engineering heritage beats rebranded OEMs.
About the author
Johnny Wayne (Wei Zhuang) is General Manager of AirSpace Machinery Co., Ltd., the Shanghai manufacturer behind ChinaCompressor.org. The company builds oil-injected and Class 0 oil-free screw compressors from 2 to 540 HP (1.5–400 kW), including the low-pressure series at 15–300 HP for 3–5 bar duty, from a 4,000 m² production facility with 20 years of engineering history. Products carry CE marking and ISO 9001:2015 certification, and we sell through distributors rather than around them.
If you are evaluating a private-label range, send the specification you were quoted to sales@chinacompressor.org and we will tell you which three lines in it decide the machine’s service life — including when the answer is that you should buy elsewhere.
Related guides
- What Should You Check in a Made in China Screw Air Compressor in 2026?
- How to Audit a Chinese Air Compressor Factory Before You Buy
- How Do You Find the Best Air Compressor for Your Textile Business in China?
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