How to reserve the ULPA leak detection interface? Upstream sampling port and on-site testability

The ULPA filter leak detection interface should consider aerosol injection, upstream mixing and sampling, downstream scanning and plugging recovery during the design stage. The number and location of interfaces need to match the air duct and method used. The leak detection interface is a typical item that is 'easy to forget during design and difficult to repair on site': if you want to add a sampling port after the equipment is completed, you will either have to make holes in the box to destroy the airtightness, or you can only temporarily insert it through the access door, making the test conditions unstable. Aili Industry isEFU equipment end fan filter unit andDuring the box structure design stage of the FFU fan filter unit , the leak detection interface is included in the structural plan. The injection point, sampling point and blocking method are clearly marked on the drawing. The interface will be there during on-site inspection and does not require temporary modification.

1. Consider injection and sampling separately: each of the two interfaces has a section of pipe

The injection point is used to create the challenge aerosol and the sampling point is used to verify upstream conditions; locations that are too close may not represent the distribution before the filter.

The injection point is responsible for sending aerosols into the air duct, and the sampling point is responsible for confirming whether the concentration distribution upstream of the filter element is uniform. If the two are too close together, the sample measured will only be the local concentration after injection, which cannot represent the state of the entire windward side of the filter element. Aili Industry isIn the structural design of the HEPA/ULPA filter matching box, the relative positions of the injection point and the sampling point are determined according to the length of the air duct and the direction of the air flow. A sufficient mixing distance is maintained after the injection point, and the sampling point is set at a stable air flow upstream of the filter element. The relationship between levels and filtering requirements can be found inISO cleanliness level comparison。

2. Check test accessibility: reserve space for takeovers, probes and personnel operations

Reserve space for pipes, probes and personnel to operate, and consider the impact of short air ducts, elbows and obstructions on mixing. A temporary hole cannot solve all your measurement needs.

The detection interface must not only have holes, but also be usable. If the sampling port is blocked by a pipeline, or the probe cannot reach the scanning position after taking over, the interface will not be used even if it is reserved. Aili Industry isIn the box structure design of the FFU fan filter unit , the location of the detection interface, surrounding pipelines, and maintenance channels are considered together.Compact models such as ultra-thin EFU still reserve a reachable path for the detection probe in a limited space. For coordination between detection interface and maintenance space, please refer toHEPA FAQs and Selection Guide。

3. The interface also belongs to the operating boundary: the sealing and valve parts must be reliably restored

The sealing cap, valve parts and penetrating structure should be reliably connected and restored to the specified state after the test is completed, and the interface location and purpose should be recorded.

The leak detection interface is part of the airtight boundary of the box in the non-detection state. If the sealing is not tight, the detection interface itself becomes a bypass path. Aili Industry isIn the design of the box of the fan filter unit at the EFU equipment end, the detection interface adopts a resealable blocking structure. The location and purpose of the interface are indicated in the structural description. After the inspection by the project party, it can be restored and recorded according to the instructions. For the sealing requirements of the internal interface of the equipment, please refer toEFU FAQ and technical support。

4. The pipeline on top of the equipment blocks the sampling port, which should be resolved during the drawing coordination stage.

If the pipeline on the top of the equipment blocks the sampling port after installation, the position should be modified during the drawing coordination stage to avoid having to bend the pipeline on site. If such problems are discovered only after the equipment is installed, the solution can often only be compromised—either bending the sampling tube to affect the sampling flow rate, or abandoning the sampling point and using an alternative location, and the test conditions are inconsistent with the plan.

Aili Industry isIn the non-standard ULPA filter and supporting box project, the location of the detection interface and the pipeline layout are coordinated on the same set of drawings. The location of the interface is confirmed with other professionals during the structural planning stage to reduce occlusion in the later stage. For the coordination between detection plan and interface location, please refer toULPA ultra-high efficiency filter FAQ and selection guide。

5. Related questions and answers

Is it possible to detect leaks if there is an upstream sampling port?
Aerosol placement, uniformity, instrument conditions, and downstream scannable range also need to be confirmed.

Can the leak detection interface be added later?
Yes, but opening holes later may destroy the airtightness of the box, or it may only be temporarily inserted through the access door, making the test conditions unstable. Setting aside during the design phase is more controllable.

Does the detection interface usually need to be blocked?
need. The interface is part of the airtight boundary in the non-detection state, and if it is not blocked tightly, it will become a bypass path.

6. Related articles

ULPA ultra-high efficiency filter FAQ and selection guide

EFU equipped with ULPA ultra-high efficiency filter

Non-standard customized ULPA ultra-high efficiency filter

HEPA FAQs and Selection Guide

7. Key points for selection and acceptance inspection

8. Product matching and technical support from Aili Industrial

Aili Industry isEFU equipment end fan filter unit andDuring the box structure design stage of the FFU fan filter unit, the leak detection interface is included in the structural plan, and the injection point, sampling point and blocking method are marked on the drawing;The HEPA/ULPA filter matching box determines the relative position of the injection point and the sampling point according to the length of the air duct and the direction of air flow. The mixing distance is maintained after the injection point; the detection interface adopts a resealable blocking structure, and the location and purpose are indicated in the structural description.The ultra-thin EFU reserves an accessible path for the detection probe in a compact space.The non-standard ULPA filter project coordinates the detection interface location and pipeline layout on the same set of drawings. 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.