281.491.2331 13839 West Bellfort Street Sugar Land, TX
281.491.2331 13839 West Bellfort Street Sugar Land, TX
ISO 9001:2015
U.S. Patents
90 + U.S. Patents
Since 1954
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Where to Use

Natural Gas Compressor Stations

Centrifugal Compressors

Reciprocating Compressors

Oil Refineries

Offshore Production Sites

Processing Plants

Mr. Big

Sometimes bigger is better. The Welker F-31 Filter Dryer is supersized for high pressure, high flow applications. With a 45-lb dry weight and 1” ports, this beefy filter has the capacity to clean and dry natural gas and instrument air for critical pneumatic instruments and operations.

Filter GuideFilter Guide
Media Cartridge
Mainstream Media

Filter Media Options

Dirt. Debris. Rust. Sulfur. Odorant. Water. Liquid hydrocarbons. Contaminants like these can clog, damage, flood, or even freeze your sensitive instruments if they’re not removed from your pneumatic supply. Welker offers 4 filter cartridge options for the F-31, each with its own proprietary blend of filter media for targeted contaminant removal.

Nice Threads

4-Step Cartridge Changeout

Mating threads on the cap and body make servicing the filter cartridge quick and easy. Simply spin the body off to access the cartridge and spin it back on after installing a replacement.

F-31 Spin Body
Believe Your Eyes

Color-Changing Moisture Indicator

Welker offers two options to help you watch out for water: a built-in moisture indicating eye and the standalone Welker MI-2 Moisture Indicator. Both indicators change from blue to pink when saturated for straightforward and easy visual verification. To monitor the saturation level of your filter cartridge, choose an F-31 with an indicating eye. Install the MI-2 downstream of your F-31 and pressure regulation to monitor moisture in your process.


F-31 Filter Dryer
Materials of ConstructionBuna, Carbon Steel, PTFE
Others Available
Connections1/4" FNPT
1" FNPT (Standard)
Nominal Filter Rating0.45 Micron
Drain Valve
ASME Coded Filter
Maximum Allowable Temperature200 °F
Operating Pressure1500 psig MAOP @ -20°F to 100 °F