Vent filter

Pipework systems, valves and vent filters should be properly designed to facilitate cleaning and sterilization. The use of clean in place and sterilize in place systems should be encouraged. Valves on fermentation vessels should be completely steam sterilizable. Air vent filters should be hydrophobic and validated for their scheduled lifespan. 

Integrity testing of vent filter membranes associated with the sterilizer... 

A suitable holding tank is sterilized in place by steam. The following sterilized parts are aseptically connected to the tank a blender valve, a safety relief valve, and a vent filter assembly containing a 0.2 im filter. Prepare the media according to manufacturer instruction. Adjust pH. 

Water storage tank vent filters must be equipped with a sterilizing air filter in order to prevent the air, which displaces water drawn from the tank, from microbiologically contaminating the water. The filter must be hydrophobic in order to prevent condensation from blinding the filter and preventing air entry or escape from the tank. It also must have a mean porosity of less than 1 pm. 

Fig. 2.46. Basic principle of a venting filter for in situ integrity tests. Arrangement of the sterile venting filters for in-line sterilization and integrity tests (I tests). The integrity tests are carried out following the water intrusion method (WIT). In this figure, WIT is carried out only at the primary filter. The secondary filter is installed as a back-up filter (police filter). 1, Primary filter with a 0.22 pm cartridge 2, secondary filter with a 0.22 pm cartridge the secondary filter can be sterilized independent-...

CPU 4, recorder 5, control panel sterile room 6, compressor 7, vacuum pumps 8, venting filter 9, condenser. 

Culture flasks with vented filter caps allow for gaseous exchange between the culture and the incubator while protecting the cells from airborne microbial contamination. 

Portable air conditioners 9 - Misc. non-equip. items, tote bins/ buggies/scales/vent filters... 

PTFE membranes are highly hydrophobic and, therefore, are used as air filters. Air filters have to be highly hydrophobic to avoid water blockage due to moisture or condensate, especially after steam sterilization of these filters. Water blockage could be detrimental, if the filter is, for example, used in a tank venting application to overcome condensation vacuum of a non-vacuum resistant tank. If the filter would not allow a free flow of air into the tank, it may implode. Therefore, vent filters for this application have to be chosen and sized with care. PTFE membranes are also highly mechanical and thermal resistant, which is required, because such filters are used over several... 

Attach vent filter with silicon tubing to air condenser. 

In purifying mixtures of gas-forming substances, activated carbon is utilized in cigarette filters (mainly in Japan), in gas-mask filters, in venting filters for car petrol tanks (mainly in the USA and Japan) and in air conditioning units for the purification of ambient air. Industry also utilizes activated carbon for the recovery of a multiplicity of volatile solvents from the ambient air, for adsorption of poisonous or noxious gases (e.g. hydrogen sulfide) and as catalysts or catalyst supports. 

A filter testing procedure will be developed to ensure that bacterial retentive air and liquid filters are integrity tested and replaced as necessary. This program will include those filters not directly in the process stream, such as vent filters on tanks and autoclaves, and compressed gas filters. This procedure will include filter integrity testing instructions, schedules, and acceptable test results. 

Crystallizers should have variable speed agitators, temperature control, and sterilizable vent filters. As many controls as possible should be located outside ofthe sterile area. The crystallization vessel should be located as close to the filtration unit as possible. Time, temperature, and agitation speed are critical variables that may need strict control during the crystallization process. The crystallization vessel should be part of a closed system and often is jacketed for glycol temperature control. 

MF is also used to remove microorganisms and particulates from air and other gases used in the pharmaceutical industry. Some specific applications include vent filters filtration of compressed air used in sterilizers, filtration of air or nitrogen used for solution transfers or at filing lines, and filtration of air or nitrogen used in fermentors. 

Again, the need for "vent-filters" has been recognized by the FDA ... 

Of course, the opposite phenomenon occurs with hydrophilic liquid filters where air bubbles are present in the liquid process stream it is called "air-binding". Often a hydrophobic vent-filter will be used in conjunction with the main hydrophilic membrane filter to allow escape of accumulated air without permitting liquid leakage. 

WFI storage tanks are equipped with hydrophobic bacterial retentive vent filters. 

Note Whenever bin vent filters are used on a storage silo, the tank must also be provided with additional pressure-vacuum relief fittings. In the event the filter becomes clogged, they will allow the tank to vent, thereby eliminating the possibility of structural damage due to over-pressurization. 

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