VICI Valco filters

There are many flow elements of analytical instruments which require protection from foreign particles, such as orifices that may become plugged or surfaces that may get scratched. However, conventional filtering devices may have too large a volume to be consistent with good system performance, particularly in chromatographic applications. Valco’s filter design results in extremely low internal volume and simplifies filter element replacement. Filter bodies are “coned” for uniform flow and maximum filter surface area. The filters are made entirely of metal, so they can be used at any instrumentation temperature. While the standard metal is 316 series stainless, filters can be made from alloys that can be used in virtually any application.

VICI Valco offers a choice of three different filtering elements. All styles are available in bulkhead configurations for mounting on a panel or instrument wall. Please note that since frits and screens have significantly different thicknesses, they cannot be used interchangeably in the same filter body.

Pressed frits, permanently installed in the filter, are recommended where contaminants are the exception and not the rule. The frits are 2μ stainless.

Removable frits are the best choice for maximum filtration, or if the application requires Hastelloy C or titanium. However, they allow more mixing and tend to clog more than screens. A 2μ frit is included with the filter, but 0.5, 2, and 10μ replacement frits are available in three materials.

Removable screens plug less rapidly and provide lower pressure drop than frits. Since they are thinner, there is less mixing and dispersal than might occur with a frit, but frits provide better filtration. A 2μ screen is included with the filter, and 2 and 10μ stainless replacement screens may be ordered.

VICI offers the following Valco filters:

Filters with a pressed frit
Pressed frit filters contain a permanently installed stainless steel 2μ frit, and are recommended for applications where contaminants are the exception and not the rule – that is, when the sample is generally clean but you wish to guard against the stray burr from a carelessly prepared tube end that might find its way into the flowpath. Standard material is Type 316 stainless.

Filters with a removable frit
These filters come with a removable 2μ frit. The standard frit can be replaced with any frit of the proper diameter, but not by a screen. These filters are suitable for streams with frequent contamination, since the filtering element is easily changed. Standard material is Type 316 series stainless.

Filters with a removable screen
These filters come with a removable 2μ screen. The standard screen can be replaced with any screen of the proper diameter, but not by a frit. These filters are suitable for streams with frequent contamination, since the filtering element is easily changed. Standard material is Type 316 series stainless.