What parameters need to be provided when purchasing HEPA high-efficiency filters?

The more complete the information provided during the inquiry, the more accurate the plan will be. However, in actual work, only a few items are often written on the purchase order, and the rest is left to the supplier to guess, or it may not be found until the sample is made.

HEPA procurement parameters can be divided into three categories: performance parameters, interface parameters, and delivery requirements. If all three categories are clearly written, the quotations will have a basis for comparison, and there will be a basis for subsequent acceptance.

Performance parameters should include test conditions

Efficiency level, rated air volume, and resistance are the basic items. But just writing 'efficient' or a percentage is not enough.

The efficiency level should indicate the applicable standards. H13 and H14 levels come from specific testing standards, and the definitions under different standards are not exactly the same. When comparing supplier plans, align the test standards with the design air volume, and check the efficiency and resistance data under the same conditions.

The rated air volume should correspond to the actual air volume used. When the design air volume is inconsistent with the test air volume, technicians are required to evaluate the difference. It is best to provide the resistance data with both the initial resistance and the recommended final resistance to facilitate the system to calculate the fan working point.

If the project has requirements for leak detection, the detection method and judgment standards must also be explained. These conditions are written in the procurement documents, and there will be a basis for comparison during acceptance. involving The selection of different levels of HEPA/ULPA air filters should also list the corresponding testing requirements.

The interface parameters determine whether it can be installed.

This type of information is most commonly missing on purchase orders.

The length, width, and thickness of the filter frame, the direction of air flow, the position of the pressing surface, and whether the sealing method is a gasket or a liquid tank—these items must correspond to the actual structure of the equipment installation frame. For liquid tank sealing products, the knife edge size or tank body size must also be provided. For specific verification methods, please refer to the relevant interface instructions.

The size of the inner opening of the installation frame, the position of the pressing parts, and the sealing contact surface are data on the equipment side and must also be provided. Only the size of the filter element is given, not the size of the installation frame. The supplier cannot judge whether it can be pressed tightly after assembly. For the old filter element replacement project, it is recommended to measure the old sample and the installation frame at the same time, because the old part may be deformed, and it may not be appropriate to make a new product directly according to the size of the old sample.

The disassembly and assembly paths should also be explained. When the internal space of the equipment is limited, even if the new filter element has the same length and width, the change in thickness may still interfere with the diffuser plate, door or access opening. 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.

The use environment will affect material selection

Temperature, humidity, exposure to special gases, and the presence of cleaners or disinfectants will affect the material selection of filter media, edge sealants, outer frames, and gaskets.

In high-humidity environments, attention should be paid to the hygroscopicity of the filter material and the moisture resistance of the edge sealing glue; in high-temperature conditions, continuous temperature and peak temperature should be distinguished; in places with corrosive gases, the outer frame material and anti-corrosion treatment should be considered. If these conditions are not provided, the supplier can only configure it according to normal working conditions, and it may fail prematurely in actual use.

For matching FFU fan filter unit or For the EFU equipment-end fan filter unit project, information on the use environment should also be provided, because the fan and control configuration of the complete machine solution are also affected by the environment.

Delivery requirements are written into the order

Quantity, unit number, packaging method, test report form, on-site leak detection responsibility, these are within the scope of delivery, and it is recommended to be clear in the order.

In batch projects, whether unit-by-unit reporting is required and whether the unit number needs to correspond to the installation location will affect the supplier's production arrangements and quotations. For non-standard products, the sample confirmation process and drawing version management method must also be agreed upon to avoid inconsistency between bulk goods and samples.

Comparable quotations should correspond to the same product range and delivery scope. Whether performance testing, unit-by-unit numbering, special packaging and on-site service are included needs to be listed separately, otherwise the price difference will be difficult to explain.

Unify technical caliber before purchasing

It is recommended that equipment, process and procurement personnel share a parameter sheet: the equipment determines the installation interface, the process determines the particle control objectives, and the procurement confirms testing, packaging and delivery conditions. Any changes require simultaneous updating of drawings and orders.

The practical benefit of this is that the same set of data is used for prototypes, batches and on-site installation. When a problem occurs, it can be quickly determined whether the product deviates from the agreement or the on-site conditions are inconsistent with the information provided during the inquiry.

About Aili Industrial’s inquiry cooperation

Aili Industrial can provide complete size, efficiency, air volume, resistance and interface information. HEPA/ULPA air filter and equipment matching solutions. filter with FFU fan filter unit、The EFU equipment-end fan filter unit is matched in the same manufacturing system, and the interface parameters can be checked together during the planning stage to reduce on-site adaptation problems.

The clearer the conditions provided during the inquiry, the easier it will be for subsequent samples to be matched with batch acceptance. Specific performance is subject to product technical information and project confirmation documents.