The Acceptance Test Was in China. The Performance Problem Was in the Field.
Quote from chief_editor on May 30, 2026, 6:44 pmFactory acceptance tests on Chinese industrial equipment confirm performance under controlled conditions. The gap between test conditions and field conditions is where performance problems originate.
A manufacturer of industrial dryers placed a factory acceptance test order with a Chinese manufacturer for a rotary drum dryer. The factory acceptance test was conducted at the manufacturer's facility in Changzhou. The test included thermal performance at specified inlet and outlet temperatures, rotation speed verification, and shell runout measurement. All parameters met specification. The test certificate was signed.
After installation at the client site in Canada, the dryer underperformed on moisture removal by approximately 18% at design throughput. Investigation identified two factors: the thermal performance test at the factory had used a lower-density feed material than the specified production material, and the factory ambient temperature during testing was 24 degrees Celsius compared to the design inlet air temperature of 38 degrees Celsius for the Canadian summer installation.
The manufacturer's position: the equipment met specification as tested. The buyer's position: the equipment does not meet specification in the installation condition. Both were correct. The specification had not defined the test conditions in sufficient detail.
Why Factory Acceptance Test Conditions Create Performance Gaps
Factory acceptance tests for thermal and process equipment are conducted under factory conditions that may differ materially from installation conditions. The test confirms that the equipment performs to a specified level in the factory environment. Whether that level corresponds to the required performance in the installation environment depends on whether the test conditions were designed to replicate the installation conditions.
For Chinese industrial equipment manufacturers, the factory acceptance test is typically designed to confirm that the equipment is mechanically complete and operationally functional. The test protocol in the purchase order is usually specified by the manufacturer rather than the buyer, and it reflects what the manufacturer can demonstrate at their facility, not necessarily what the buyer needs to verify for the installation.
The gap between factory test conditions and field conditions is widest for equipment whose performance depends on environmental inputs that vary between factory and installation: dryers and evaporators where ambient temperature and humidity affect thermal performance, pumps where inlet conditions affect cavitation behavior, compressors where suction temperature and composition affect capacity and efficiency, heat exchangers where fouling characteristics of the actual process fluid differ from clean water test conditions.
In each case, a factory acceptance test conducted at conditions that differ from the installation conditions produces performance data that is real but not transferable to the installation without correction factors. If those correction factors are not applied -- either because the test specification did not define them or because the buyer's acceptance of the factory test results implied acceptance of the factory conditions as representative -- the performance problem in the field is not a product defect. It is a specification gap.
The Test Protocol Language That Closes the Gap
A factory acceptance test protocol that generates meaningful performance evidence for the installation environment specifies: the test conditions that will be used (feed material properties, inlet air conditions, test fluid characteristics), the correction factors that will be applied to convert test performance at factory conditions to expected performance at installation conditions, and the acceptance criteria in terms of installation performance, not factory test performance.
For Chinese manufacturers who cannot replicate installation conditions at their facility, the alternative is a witnessed commissioning test at the installation site, with the manufacturer obligated to attend and demonstrate specification compliance at site conditions before the commissioning acceptance certificate is signed. This is a more commercially demanding requirement than a factory acceptance test. It is also the test that actually verifies what the buyer needs to verify.
The Changzhou rotary dryer's factory acceptance test confirmed that the equipment was mechanically correct and thermally functional under factory conditions. It did not confirm that the equipment would meet specification in Canada in summer. Those are two different tests. Only one of them was conducted. Understanding which one your factory acceptance test protocol is actually conducting requires reading the protocol against the installation conditions it is meant to verify.
Factory acceptance tests on Chinese industrial equipment confirm performance under controlled conditions. The gap between test conditions and field conditions is where performance problems originate.
A manufacturer of industrial dryers placed a factory acceptance test order with a Chinese manufacturer for a rotary drum dryer. The factory acceptance test was conducted at the manufacturer's facility in Changzhou. The test included thermal performance at specified inlet and outlet temperatures, rotation speed verification, and shell runout measurement. All parameters met specification. The test certificate was signed.
After installation at the client site in Canada, the dryer underperformed on moisture removal by approximately 18% at design throughput. Investigation identified two factors: the thermal performance test at the factory had used a lower-density feed material than the specified production material, and the factory ambient temperature during testing was 24 degrees Celsius compared to the design inlet air temperature of 38 degrees Celsius for the Canadian summer installation.
The manufacturer's position: the equipment met specification as tested. The buyer's position: the equipment does not meet specification in the installation condition. Both were correct. The specification had not defined the test conditions in sufficient detail.
Why Factory Acceptance Test Conditions Create Performance Gaps
Factory acceptance tests for thermal and process equipment are conducted under factory conditions that may differ materially from installation conditions. The test confirms that the equipment performs to a specified level in the factory environment. Whether that level corresponds to the required performance in the installation environment depends on whether the test conditions were designed to replicate the installation conditions.
For Chinese industrial equipment manufacturers, the factory acceptance test is typically designed to confirm that the equipment is mechanically complete and operationally functional. The test protocol in the purchase order is usually specified by the manufacturer rather than the buyer, and it reflects what the manufacturer can demonstrate at their facility, not necessarily what the buyer needs to verify for the installation.
The gap between factory test conditions and field conditions is widest for equipment whose performance depends on environmental inputs that vary between factory and installation: dryers and evaporators where ambient temperature and humidity affect thermal performance, pumps where inlet conditions affect cavitation behavior, compressors where suction temperature and composition affect capacity and efficiency, heat exchangers where fouling characteristics of the actual process fluid differ from clean water test conditions.
In each case, a factory acceptance test conducted at conditions that differ from the installation conditions produces performance data that is real but not transferable to the installation without correction factors. If those correction factors are not applied -- either because the test specification did not define them or because the buyer's acceptance of the factory test results implied acceptance of the factory conditions as representative -- the performance problem in the field is not a product defect. It is a specification gap.
The Test Protocol Language That Closes the Gap
A factory acceptance test protocol that generates meaningful performance evidence for the installation environment specifies: the test conditions that will be used (feed material properties, inlet air conditions, test fluid characteristics), the correction factors that will be applied to convert test performance at factory conditions to expected performance at installation conditions, and the acceptance criteria in terms of installation performance, not factory test performance.
For Chinese manufacturers who cannot replicate installation conditions at their facility, the alternative is a witnessed commissioning test at the installation site, with the manufacturer obligated to attend and demonstrate specification compliance at site conditions before the commissioning acceptance certificate is signed. This is a more commercially demanding requirement than a factory acceptance test. It is also the test that actually verifies what the buyer needs to verify.
The Changzhou rotary dryer's factory acceptance test confirmed that the equipment was mechanically correct and thermally functional under factory conditions. It did not confirm that the equipment would meet specification in Canada in summer. Those are two different tests. Only one of them was conducted. Understanding which one your factory acceptance test protocol is actually conducting requires reading the protocol against the installation conditions it is meant to verify.