How to measure the size of high efficiency filter?

The phrase '610×610 filter' often appears in procurement communication, but it actually doesn't mean much. 610 is the length of the outer frame of this product, or the size of the device opening? What's the thickness? Where is the sealing surface?

The outer frame size and the device opening size are two sets of data. Only a number is reported, and the supplier cannot confirm whether it can be installed. When measuring, record them separately and clearly mark the objects corresponding to each item.

Confirm the measurement object first

When replacing a filter element, more than one object needs to be measured.

The outer frame of the old filter element : the actual dimensions in the three directions of length, width and thickness. If it is a non-standard product, the outer frame material and structural form must also be recorded.

Air flow direction : The air flow arrow on the old filter element points to the direction, or the air flow direction can be determined based on the installation position. This item is easily overlooked during replacement, but installing it upside down will cause changes in wind speed distribution and sealing status.

Installation frame inner opening : the size of the opening on the equipment used to install the filter element. This is what the new product will ultimately work with.

Sealing contact surface : the position where the gasket is pressed, or the position of the knife edge of the liquid tank. This item determines whether the sealing structure can be aligned.

Position of the compression parts : The position and number of the compression bolts, buckles or strips affect whether the outer frame of the new filter element can be compressed evenly.

Disassembly and assembly space : the operating space required to remove and install the filter element. Equipment covers, pipelines, and diffusers may affect the disassembly and assembly paths.

The outer frame size and installation opening should be measured separately.

These two data are often mixed together, leading to selection errors.

The outer frame size is the size of the filter itself and is used to confirm product specifications. The installation opening size is the opening on the equipment and is used to confirm whether the filter can be installed. There is a matching relationship between the two, but they are not the same number.

It is recommended to record the measurements separately and mark their respective positions and datum planes on the drawings. If the old filter element has been deformed, you cannot directly use the deformed size as the new product specification. You should refer to the size of the installation frame and refer to the design size of the old filter element. For matching The filter element used in the FFU fan filter unit and the interface size on the box side must also be measured because the sealing surface of the filter element matches the box. Device-side applications such as The EFU equipment-end fan filter unit has a compact internal space and requires higher measurement accuracy of the installation frame.

Look at the thickness and disassembly and assembly path together

Even if the length and width of the new filter element are the same, changes in thickness may still interfere with the diffuser plate, door or access opening.

When measuring the thickness, measure the actual thickness of the outer frame, not the thickness of the filter material part. If the original system uses a liquid tank sealing structure, the depth of the tank and the position of the knife edge must also be recorded. For specific verification methods, please refer to the relevant instructions on knife edge size verification.

How to confirm the disassembly and assembly path: simulate the removal and installation actions to see if there are any obstacles on the path. When the old filter element cannot be safely removed on site, the replacement path should be clarified first, and then the new filter element structure should be determined. In some locations, the flow plate or other parts need to be disassembled before the filter element can be replaced. These operating steps should also be recorded as a reference for subsequent maintenance.

Closed loop with drawings for non-standard projects

After the measurement is completed, organize the data into drawings or record sheets.

The drawings should indicate: the length and width of the outer frame, the size of the installation opening, the position of the sealing surface, the direction of air flow, the position of the pressing parts and the direction of disassembly and assembly. After this information is provided to the supplier, the other party can confirm product specifications or propose items that require further verification.

After the order drawing is confirmed, the goods will be accepted according to the same drawing. When the size or sealing method changes, update the drawing version and reconfirm it to avoid inconsistency between the batch product and the confirmed version.

involving Products of different grades of HEPA/ULPA air filters have the same measurement methods, but the sealing structure and testing requirements may be different, and should be marked separately on the drawings.

Measurement records for replacement of old filter elements

For embedded filter elements, it is recommended to draw a simplified diagram of the outer frame, openings and pressing parts, and mark the measurement reference plane on the diagram.

If the old part has been deformed, do not directly regard the deformed size as the nominal size of the new product; you should measure the relatively complete installation frame at the same time and compare the two to judge. Keep photos of the measurement data, which can reduce back-and-forth confirmation when communicating with suppliers later.

For batch replacement projects, it is recommended to select a representative location for measurement, confirm the plan, and then promote it to other locations. If there are differences in the installation frames at different locations, they need to be measured separately to confirm.

About Aili Industrial’s size verification and cooperation

Aili Industrial provides HEPA products of different sizes and structures as well as non-standard accessories. filter with FFU fan filter unit、The EFU equipment-end fan filter unit is matched in the same manufacturing system, and the interface dimensions of the installation frame and filter element can be checked together during the planning stage.

Confirming the installation frame, sealing surface and replacement path before ordering can reduce equipment modification and repeated disassembly and assembly. Specific specifications are subject to confirmed drawings and project technical documents.