How to confirm the performance of the complete machine after the U17 filter element is installed in the equipment?

Let’s first clarify a confusing concept: U17 is the grade mark of the filter itself, which describes the performance of a filter element under test conditions. After installing this filter element into the equipment, the air outlet of the whole machine or the internal environment of the equipment cannot be directly called 'U17 level'.

Overall performance is another matter. It is determined by the filter element, box, seal, fan and air flow organization. Installing it is just the beginning, there are a few things to verify.

First confirm the filter body

The first step is to return to the filter element itself.

Check applicable standards and testing records. The standard version, test conditions and finished product test report corresponding to U17 must be consistent with the installed parts. Model numbers, serial numbers and materials cannot be changed without confirmation.

Check appearance and structure. Check whether the outer frame is deformed, whether the filter material is damaged, and whether the sealing surface is intact. Problems during transportation and handling are easier to deal with if they are discovered before installation than after installation.

Confirm the installation direction. The air path inside the equipment may not be straight, and just looking at the arrow on the filter element may not be enough. To confirm along the actual air flow path, please refer to the instructions related to the ULPA air inlet and outlet directions for specific methods.

Check all bypass interfaces

This is the most critical part of the whole machine verification.

The connection between the filter element and the box. The tightness of the sealing gasket or the matching state of the liquid tank need to be confirmed according to the design requirements.

Access openings and connection holes. There may be various openings on the equipment box, and unclosed holes will become bypasses.

Splicing. If the box is made of multiple panels, the sealing status of the joints must also be checked.

Even if the performance of the filter element is qualified, the system still needs to detect leaks within the agreed range. An unsealed cable hole is enough to allow unfiltered air to flow around the filter element and into the clean side. The leak detection scope should cover the filter surface and all accessible interfaces, and the methods and criteria should be implemented according to the project plan. For specific troubleshooting methods, please refer to the relevant instructions for inspection after reverse installation.

Separate measurement of air supply and process area

The performance verification of the whole machine should be divided into two levels.

Air supply conditions. Measure the wind speed distribution and uniformity under the working air volume to confirm that it meets the design requirements. The resistance of U17 is usually higher than that of low-grade filter elements. It is necessary to confirm whether the working point of the fan matches. involving The equipment-side application of the EFU equipment-side fan filter unit has a compact internal space and the airflow distribution is greatly affected by the structure. The actual operating status of the equipment must be considered when measuring.

Process area results. The particle concentration in the protective area inside the equipment must be measured according to project requirements. This item does not have a one-to-one relationship with the filter grade - dust production, airflow obstruction, and operating conditions inside the equipment will all affect the results.

The records must correspond. The filter element number, installation location, test conditions and results must be able to correspond. This set of records will serve as the basis for judgment during subsequent replacement or troubleshooting. Supporting FFU fan filter unit system, unit parameters and single unit data must also be recorded.

Project judgment example

After a U17 filter element is installed in a piece of equipment, the whole machine is considered to be a 'U17 level' clean environment.

This statement is not accurate. U17 describes the performance of the filter element, and the overall machine environment also needs to meet a series of conditions such as air volume, sealing, and air flow organization. If there are unsealed holes in the box, or the air supply volume is insufficient, even if a U17 filter element is installed, the actual particle concentration inside the device may not meet expectations.

The correct approach is to regard filter element testing, installation leak detection and area testing as three independent verification links, confirm and record them separately. involving Products of different grades of HEPA/ULPA air filters have the same verification methods, and the criteria are implemented according to corresponding standards.

Selection and Acceptance Checklist

About Aili Industrial’s complete machine verification cooperation

The core of the whole machine performance verification is to check the filter element, box, fan and structure under the same conditions.

Aili Industrial's manufacturing system covers filters, motors, fans, control systems and complete machine assembly, and can provide ULPA ultra-high efficiency filter and supporting air supply equipment. filter with When the EFU equipment-end fan filter unit is matched, the filter element resistance and fan working point can be calculated together at the planning stage, and the installation interface and sealing structure can also be uniformly confirmed to reduce problems caused by interface mismatch after installation.

When enquiring, provide the internal structure of the equipment, available space, target air volume and testing requirements, which will help confirm the complete machine configuration. Specific performance is subject to product technical data and project acceptance results.