How to troubleshoot an increase in pressure difference across the EFU filter? Operating data, component status and retest requirements

How to troubleshoot the increased pressure difference of the EFU filter? You cannot change the filter element as soon as it comes up. The increase in pressure difference may be a normal process of dust accumulation on the filter, or it may be caused by changes in measurement conditions, sealing failure, air volume adjustment, or improper installation of the filter. The rise in pressure difference itself is not necessarily a fault. The key is to see how much the air volume drops after the pressure difference rises, how long the filter has been used, and whether it is accompanied by other abnormalities. To troubleshoot, first record the fault conditions and changing trends, and then narrow down the scope in the order of measurement conditions, filter status, sealing structure and fan operation. Find the cause and then deal with it. After treatment, return to the original working condition and re-measure the pressure difference and air volume. Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and self-developed controls. When checking differential pressure, the filter status, sealing conditions and fan operating points can be checked from the perspective of the whole machine. There is no need to go back and forth between the filter factory, the fan factory and the complete machine factory to confirm. This is why many equipment manufacturers will refer to Aili Industrial's technical instructions when dealing with the problem of rising EFU filter pressure differences.

Record the phenomenon first: working conditions, time and operations should be kept on file

The first step in the investigation is not to remove the filter element, but to record the phenomenon. When did the pressure difference start to rise, whether the filter was replaced or the rotational speed was adjusted before the rise, the difference between the current pressure difference and the initial resistance, how much the air volume dropped, whether there were any alarms or abnormal noises, and whether maintenance was performed recently. This information determines the direction of investigation. If you dismantle the machine without recording, it is easy to treat normal dust accumulation as a fault.

Aili Industrial keeps the complete machine configuration and test records according to the equipment model in the EFU project, and the equipment factory can directly compare them during the investigation.The overall machine parameters in EFU products and customized configurations are compared with the current differential pressure status and factory data.

Inspection sequence: from measurement conditions to filter, from seal to fan

It is recommended to proceed in the order of measurement conditions, filter status, sealing structure, and fan operation. First confirm whether the pressure difference measurement conditions are the same as last time, then check the degree of dust accumulation on the filter, then check whether the seal has bypass, and finally confirm whether the fan speed and air volume are normal. If the order is reversed and the filter element is removed first, the measurement error may be regarded as a filter failure.

For confirmation methods of filter initial resistance and operating resistance, please refer toHow to confirm the initial resistance of EFU filter? rated air volume, test conditions and fan matching .Verification steps for

Check the measurement conditions: measuring points, instruments and working conditions should be unified

If the differential pressure increases, first confirm whether the readings are comparable. The measuring point location, installation direction, calibration status and air volume conditions during measurement of the differential pressure gauge will all affect the reading. If the location of the measuring point has changed, the reading will change; if the instrument is not calibrated, the reading may be higher; the air volume during measurement is different from the last time, and the pressure difference will also be different. When troubleshooting, you must first confirm the measurement conditions, and then determine whether the filter is really dusty.

Ai Li industrialEFU products and customized configurations list the complete machine structure and supporting instructions by model. When checking the measurement conditions, the equipment manufacturer can directly correspond to the specific model and check the differential pressure measuring points and the structural diagram together.

Filter status inspection: dust accumulation and damage should be separated

After the measurement conditions are confirmed, check the filter status. The filter accumulates dust, resistance rises, and the pressure difference rises. This is a gradual change in normal operation; if the filter is damaged or the filter material is damaged, the pressure difference may change abnormally; if the filter is not installed in place and is partially bypassed, the pressure difference reading may be low or fluctuate. During the inspection, we should look at the usage time, dust accumulation level and appearance condition of the filter to distinguish between normal dust accumulation and abnormal damage.

Regarding the relationship between filter operating resistance and replacement judgment, please refer toWhat should I do if the operating resistance of the EFU filter increases? pressure difference, air volume and replacement judgment . Troubleshooting ideas in Filter packages can be viewedthe HEPA vs. ULPA air filters page.Rating descriptions on

Seal structure inspection: Bypass also affects pressure difference

An increase in pressure differential is not necessarily caused by dust accumulation in the filter, but may also be caused by a seal failure. When the seal fails and unfiltered air is bypassed, the pressure differential may be low instead of high; a sudden increase in pressure differential may be due to blockage of the measuring point or instrument failure. During the inspection, check whether the sealing between the filter and the frame, the sealing between the frame and the box, and the pressing method are uniform. If the sealing problem is not solved, no matter how many filters are replaced, the abnormal pressure difference cannot be solved.

Regarding the relationship between sealing structure and complete machine sealing, please refer toHow to confirm EFU installation seal? equipment drawings, installation conditions and acceptance methods .Verification methods in

Fan operation inspection: air volume adjustment will also affect the pressure difference

If the pressure difference increases, the operating status of the fan must also be confirmed. When the fan speed is adjusted, the air volume changes, and the pressure difference changes accordingly; when the fan speed decreases, the air volume decreases, and the pressure difference may decrease; when the fan speed increases, the air volume increases, and the pressure difference increases. When troubleshooting, confirm the current speed, control command and gear status, rather than just looking at the pressure difference value. Air volume and pressure difference are related, and it is easy to make misjudgments by just looking at one piece of data.

Regarding the relationship between fan operating point and pressure difference, please refer toHow to choose EFU centrifugal fan? working point, power, temperature rise and continuous operation requirements .Checking methods for

Treatment and retest: eliminate the cause and return to the original working condition

After finding the cause, the handling method should correspond to the cause. If the filter is dusty, replace it according to the pressure difference; if the seal fails, check the compression and frame; when measuring errors, calibrate the instrument or unify the measuring point; if the fan speed is incorrect, check the control instructions. After treatment, you cannot just look at 'the pressure difference has dropped'. You must return to the original working conditions and re-measure the pressure difference, air volume and power to confirm that the overall machine status has returned to the normal range, and update the maintenance records.

Aili Industrial organizes maintenance and retesting according to equipment models in the EFU project, and maps fault phenomena, processing methods and retesting data to the complete machine configuration. Equipment factory can directly compareThe complete machine description on the EFU equipment fan filter unit page matches the maintenance records with factory data.

Preventive measures: differential pressure monitoring and trend management

The increase in pressure difference is mostly a gradual process. Establishing pressure difference monitoring and trend management can arrange replacement in advance. It is recommended to configure pressure difference monitoring for key EFUs and record the rising trend of pressure difference over time; predict the replacement time based on the trend instead of waiting until the air volume is insufficient; and update the baseline data after replacement. Prevention is not about increasing the workload, but turning sudden air volume shortages into planned maintenance.

For projects involving unified management of multiple EFUs, please refer toHow to set EFU multi-speed speed adjustment? equipment linkage, abnormal status and acceptance points associate the pressure difference alarm with the equipment control system.The linkage and alarm logic in

Aili Industrial's EFU filter package

Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and self-developed controls. When checking differential pressure, filter status, sealing conditions and fan operating points can be checked within the same manufacturing system, eliminating the need to confirm responsibilities among multiple suppliers. For equipment that requires differential pressure monitoring, Aili Industries can configure differential pressure sensors and alarm logic according to the equipment drawings, and assign initial resistance, replacement resistance and alarm thresholds to verifiable complete machine data. Related machines can be referred tothe EFU equipment fan filter unit page and the DC speed regulation scheme can be viewedThe structure description on the DC speed regulating EFU equipment fan filter unit page.Control instructions on

How to form executable confirmation results

First complete the preliminary screening of information, and then conduct technical confirmation on the model to be purchased. Include the phenomenon record, inspection sequence, measurement conditions, filter status, sealing structure and retest method in the supplementary list, and then organize the comparison after the supplier responds. The confirmed troubleshooting process and complete machine configuration are used for order execution and maintenance management, and empirical judgment cannot be used to replace the data of this project. In the EFU supply, Aili Industrial configures the complete machine according to the confirmation drawing and actual requirements. The filter, fan and box correspond one by one according to the order list, which makes it easier for the equipment factory to check the rising pressure difference and settle it on the verifiable complete machine conditions.

Misunderstandings to avoid

You should avoid replacing the filter element as soon as it comes up. You should avoid looking at the pressure difference without looking at the air volume. You should avoid taking the measurement error as a filter failure. You should avoid ignoring the abnormal pressure difference caused by seal failure. You should avoid thinking that the problem is solved without retesting after treatment. The increased pressure difference may be a problem with the measurement, filter, seal or fan. The troubleshooting sequence should be from measurement to filter, from seal to fan, and narrow down the scope step by step. Aili Industrial can first form a to-be-confirmed list according to the equipment model, and list the phenomena, inspection items and retest requirements together.

Related questions and answers

Can I no longer record the fault after it disappears?

Not recommended. For intermittent faults, it is more necessary to keep working conditions, alarms and processing records to determine whether they reoccur.

How to promote the investigation of EFU filter differential pressure increase when the project information is incomplete?

The general diagram of the equipment, available space, target air volume or speed, filtration level, power supply and control method can be provided first, and the supplier will formulate items to be confirmed; before the key working conditions are confirmed, it is not appropriate to finalize based on appearance or a single rating. Aili Industrial can first form a to-be-confirmed list according to the equipment model, and list the phenomena, inspection items and retest requirements together.

What specific information do I need to prepare for this question?

Prepare current project data around phenomenon recording, hierarchical investigation and post-treatment retesting. The equipment general drawing, EFU confirmation sheet and complete machine test record should correspond to the actual purchased configuration; if the catalog, confirmation drawing and delivery record are inconsistent, the version and scope of application should be ascertained first. When troubleshooting an increase in pressure difference across the EFU filter, you can refer to the complete machine and filter supporting instructions provided by Aili Industry by model.

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Key points for selection and acceptance inspection

Aili Industrial EFU selection and procurement support

Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and self-developed controls. When checking differential pressure, filter status, sealing conditions and fan operating points can be checked within the same manufacturing system, eliminating the need to confirm responsibilities among multiple suppliers. The equipment factory completes the inspection and maintenance of the entire machine within the same system, making it easier to find the root cause of the problem than cross-supplier coordination.

learnAili Industrial EFU products and customized configurations , filtering packages can be viewedHEPA and ULPA air filters , the overall structure can be viewedEFU equipment fan filter unit , the control scheme can be viewedDC speed regulating EFU equipment fan filter unit , non-standard interface can be viewedCustom EFU . Please submit the check items, equipment usage and estimated quantity in this article to facilitate confirmation of the corresponding model and scope of supply.