What should I do if the ULPA sealing surface is uneven or the box is not square? Installation and rectification

When the sealing surface of the ULPA filter is uneven or the box is not square, priority should be given to rectifying the load-bearing and interface structures. Pressing the filter element in with abnormal force may damage the frame, gasket and glue seam at the same time. The uneven sealing surface and uneven box body often coexist. If only one side is changed, the problem on the other side will reappear during assembly. Aili Industrial has its own sheet metal processing production line. The squareness and flatness of the box are controlled during the processing process. The filter frame and the box are produced in the same system. The superposition relationship of the deviations on both sides can be checked before leaving the factory, which reduces the situation of having to rely on hard installation on site.

1. Measure the structural deviation: first distinguish whether it is manufacturing deviation, installation deviation or long-term stress

Check the flatness, diagonal line, support height and deformation position of the contact surface to confirm whether it is caused by manufacturing, installation or long-term stress.

The three sources are handled in different ways: manufacturing deviations need to be controlled from the processing link, installation deviations need to adjust the support and fastening sequence, and long-term stress needs to evaluate whether the structural stiffness is sufficient. Aili Industry isDuring the processing of the HEPA/ULPA filter frame and matching box, there is a process inspection for the flatness and diagonal of the contact surface. The project team can use these data to determine which side the deviation comes from. The squareness of the ceiling box can be combinedCheck the structural description of the FFU fan filter unit .

2. Evaluate the impact of rectification on sealing: it cannot be covered up by superimposing gaskets or partial glue repair.

There must be a clear plan for adjusting the bracket, repairing the interface, or replacing parts. Do not randomly add gaskets or apply local glue to cover up the problem.

An extra layer of sealing strips may change the compression and positioning, and local glue filling may conceal the true air leakage path. Aili Industry isWhen encountering interface deviations in non-standard ULPA filter projects, the rectification methods will be evaluated from both sides of the filter frame and box, instead of just letting the site make a fuss about the seals. For the boundary conditions of sealing surface rectification, please refer toHEPA FAQs and Selection Guide。

3. If the box is not square, check the diagonal, not just the long side.

When one side is pressed in place and there is an obvious gap on the other side, the squareness of the box should be confirmed first to avoid continuing to apply torque to the filter frame. Diagonal misalignment will cause the filter element to have localized interference on one side, while the long side dimensions will appear normal.

The squareness of the box is a process indicator for sheet metal processing. Aili Industrial's sheet metal production line has diagonal inspection after box processing, which can control the squareness deviation before leaving the factory. When there is a gap on site, the box processing data can be retrieved and compared with the measured data of the filter frame to determine whether it is a box deviation, a filter frame deviation, or an extreme combination of the two. For the squareness requirements of the internal box of the equipment, please refer tothe fan filter unit on the EFU equipment side .Instructions related to

4. Status verification after rectification: the leak detection conclusion should correspond to the current status

Recheck the filter element fit, fixation and sealing, and review adjacent connections if necessary. The leak detection conclusion should correspond to the final installation status.

After structural rectification, leak detection must be done again and cannot be replaced by the report before rectification. Aili Industry isWhen the ULPA ultra-high efficiency filter is delivered, it can cooperate with the project party to confirm the installation status after rectification, and record the rectification content, retest results and final configuration accordingly. For the relationship between rectification and re-inspection, please refer toULPA ultra-high efficiency filter FAQ and selection guide。

5. Related questions and answers

Can an extra layer of sealing strips solve the problem?
Compression and positioning may change and should be evaluated based on interface design and cannot be used as a universal solution for all unevenness problems.

The cabinet is not square. Should I change the cabinet or the filter frame?
The diagonal should be measured first to confirm the source of the deviation, and then the side to be corrected should be decided. Both sides need to be checked, changing only one side may cause the problem to shift.

Do I need to re-check for leaks after rectification?
need. Structural rectification changes the installation status. The leak detection conclusion should correspond to the final status and cannot be replaced by the report before rectification.

6. Related articles

ULPA ultra-high efficiency filter FAQ and selection guide

HEPA FAQs and Selection Guide

FFU FAQ and technical support

EFU FAQ and technical support

7. Key points for selection and acceptance inspection

8. Product matching and technical support from Aili Industrial

Aili Industry has its own sheet metal processing production line. After the box is processed, there is a contact surface flatness and diagonal inspection, which can control the squareness deviation before leaving the factory;The HEPA/ULPA filter frame and matching box are produced in the same manufacturing system. When there is a gap on site, the processing data on both sides can be retrieved and compared to determine the source of the deviation.the non-standard ULPA filter project encounters interface deviation, evaluate the rectification methods from both sides of the filter frame and box.When The FFU fan filter unit can check the squareness of the ceiling box.The EFU equipment-side fan filter unit can check the internal box requirements of the equipment.The delivery of ULPA ultra-high efficiency filters can be accompanied by recording of the rectified installation status. Provide process objectives, installation drawings, operating conditions and acceptance requirements, and can further communicate ULPA standard specifications, non-standard interfaces, samples and batch matching. The specific parameters and test range are based on the confirmed model and technical documents.