How are ULPA dimensions measured? Replace old filter element and check arrival size

The replacement size of the ULPA filter should be measured at the same time as the outer frame, thickness and sealing interface, and checked with the original drawing and installation port. Only measure one edge or place an order based on the old model name. It is easy to miss the space occupied by the liquid tank, flange and gasket. Dimensional measurement is not to measure the length, width and height, but to measure the complete set of dimensions of the filter element and the installation structure. Aili Industry isNon-standard ULPA filter customization and sample matching can provide size verification support to reduce rework during replacement.

1. Establish a unified measurement benchmark

Clarify the directions of width, height, and thickness as well as the starting point of measurement, and record the dimensions of the bare frame and the spacer included respectively. If the old parts have been compressed or deformed, the status should be noted, and abnormal dimensions should not be regarded as design values.

Inconsistent definition of direction is a common reason why dimensional data cannot be compared. The measurement record should indicate which side the measurement was taken from and whether seals were included. The relationship between levels and filtering requirements can be found inISO cleanliness level comparison。

2. Measure the matching dimensions together

Check the clear installation opening, support steps, sealing surface width and tightening position. The liquid tank structure also needs to check the relationship between the tank body and the knife edge to avoid incompatible interfaces due to the same appearance.

The matching size determines whether the filter element can be installed and effectively sealed, which is more critical than the overall size.The liquid tank sealed ULPA filter has additional requirements on the relationship between the tank body and the knife edge, which should be recorded separately during measurement. Please refer to the key points for measuring the interface installed inside the equipment.the fan filter unit on the EFU equipment side .Instructions related to

3. Distinguish between the size of the bare frame and the size with seals

For the same filter element, the bare frame size is different from the total size after installing a gasket or liquid tank structure. If you mix the two when replacing, it may happen that it can be installed but cannot be pressed tightly, or it may be pressed tightly but cannot be installed.

It is recommended to fill in the measurement record in two columns and mark the measurement tools and locations. For the corresponding relationship between sealing methods and sizes, please refer toHEPA FAQs and Selection Guide。

4. The status of old parts will affect the measurement results

The old gasket becomes thinner after long-term pressure, and the measured total thickness is too small. If you place an order directly based on the thickness of the old part, the new part may be thicker and the pressing stroke during installation may be insufficient.

The confirmed design specifications should be used when replacing, and the assembly allowance of the new gasket should be checked. Aili Industry isIn the customization stage of non-standard ULPA filters, the status of the old parts and the actual measurement data of the installation port can be combined to confirm the size and sealing fit of the new parts. If necessary, sample test installation can be done first.

5. Check the arrival according to the drawings

Check critical dimensions and deviations against drawing versions and record measurement tools and locations. Do not cut the frame or squeeze the filter element to force it in without permission.

When a deviation is found during the arrival review, the drawing version and the measurement benchmark should be checked first, and then whether it is a manufacturing deviation or an inconsistency in measurement caliber. Ceiling projects can be combinedCheck the size of the installation interface of the FFU fan filter unit .

6. Related questions and answers

Can photos be taken instead of size drawings?
Photos can help confirm structure, but critical fit dimensions still need to be physically measured and produced on verifiable drawings. With only photos, the manufacturer cannot determine tolerances and fitting allowances.

Can I still measure the old filter element if it is deformed?
It can be used as a reference, but the deformation state should be noted, and the actual measured dimensions of the installation port and the original drawing shall prevail. Taking the size of the deformed part directly as the design value can easily cause the new part to be too small or too large.

Can it be directly replaced if the dimensions are the same?
uncertain. It is also necessary to check the thickness, sealing surface position, frame form and compression structure. The dimensions are the same but the sealing structure is different, and bypass may occur after installation.

7. Related articles

ULPA ultra-high efficiency filter FAQ and selection guide

HEPA FAQs and Selection Guide

EFU FAQ and technical support

ISO cleanliness level comparison

8. Key points for selection and acceptance inspection

9. Product matching and technical support from Aili Industrial

Aili Industrial canThe ULPA filter size, sheet metal interface, fan space and complete machine assembly are checked under the same drawing.The non-standard ULPA filter project can provide the equipment opening, installation direction, target air volume and testing space. First confirm the sample fit and then arrange the batch. Ceiling projects can be combinedFFU fan filter unit discusses the installation interface, and the equipment-side projects can be checked at the same timeEFU equipment side fan filter unit . Provide process objectives, installation drawings, operating conditions and acceptance requirements for further communicationULPA ultra-high efficiency filters . Standard specifications, non-standard interfaces, samples and batch matching of The specific parameters and test range are based on the confirmed model and technical documents.