281.491.2331 13839 West Bellfort Street Sugar Land, Texas
281.491.2331 13839 West Bellfort Street Sugar Land, Texas
ISO 9001:2015
U.S. Patents
90 + U.S. Patents
Since 1954
Get A Quote

CleanFlow™ F-31

WELKER > Filtration > CleanFlow™ F-31

Where to Use

  • As part of a seal support system for centrifugal and reciprocating compressors with dry gas seals

  • Upstream of pneumatically actuated emergency shutdown valves

  • Upstream of sensitive pneumatic instruments in remote locations


Support System

The Welker CleanFlow™ F-31 Instrument Grade Gas Conditioning System is designed to provide a continuous supply of clean, dry gas to critical pneumatic instruments and industrial equipment.

This simple, low maintenance system includes 2 or 4 of Welker’s high-capacity F-31 Filter Dryers to accommodate high-pressure, high-flow gas streams. With a long service interval, these efficient filters maximize reliable operation.

IOM - 4 FiltersIOM-045
IOM - 2 FiltersIOM-174
The Best Defense is a Good Offense

Superior Instrument Protection

At the heart of all CleanFlow™ configurations is the industry-recognized Welker Filter Dryer, which effectively removes the contaminants natural gas picks up as it flows through pipelines.

The F-31 is super-sized 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 applications.

For wet gas streams, a Welker ALD Automatic Liquid Dump separates aerosols, free liquids, and compressor oil prior to filtration, increasing the interval between cartridge replacements.

CleanFlow F-31
Seeing Double

Built-In Backup

Each CleanFlow™ F-31 system is essentially 2 gas conditioning systems in 1: a primary and a backup. The primary system consists of 1 or 2 F-31s. Two Filter Dryers operating in parallel increases the flow rate and are ideal for a range of gas flow rates. The backup system can then be put into service whenever the primary Filter Dryers require maintenance, reducing interruption to operation.

Take the guesswork out of filter cartridge changeouts by adding a differential pressure gauge. Visually monitor filter cartridge capacity at the gauge and replace the filter cartridge when differential pressure increases to keep the gas supply clean and dry.

Mainstream Media

Filter Media Options

Dirt. Debris. Rust. Sulfur. Odorant. Water. Liquid Hydrocarbons. Contaminants like these can undermine the performance of your dry gas seals and clog, damage, flood, or even freeze your sensitive instruments if they’re not removed from your pneumatic supply.

Welker offers 3 filter cartridge options for the CleanFlow™ F-31, each with its own proprietary blend of filter media for targeted contaminant removal.

Media Cartridge
Moisture Indicator
Believe Your Eyes

Color-Changing Moisture Indicator

Monitor the saturation level of your filter cartridge with Welker’s built-in moisture indicating eye. The indicating eye will change from blue to pink when saturated for straightforward and easy visual verification.

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.

Spin Off Body


CleanFlow™ F-31
CleanFlow™ F-31
Materials of ConstructionBuna, Carbon Steel, PTFE, and Stainless Steel (Valves & Fittings)
ConnectionsInlet & Outlet: 1” FNPT
Inlet & Outlet: 1½” FNPT
Flow RateSingle Filter: Up to 182 scfm
Dual Filter: Up to 300 scfm
With ALD: 100 scfm
Nominal Filter RatingUp to 4 Microns
Filter Media to RemoveMoisture
Moisture, Liquid Hydrocarbons, and Odorant and Mercaptan
Odorant and Mercaptan

Maximum Allowable Temperature200 °F
Operating Pressure1500 psig*
*Temperature Limited by Valves
FeaturesWelker F-31 Filter Dryers (2 for Single or Dual Service; 4 for Dual or Quad Service)
OptionBuilt-in Moisture Indicator
Differential Pressure Gauge(s)
Welker ALD Automatic Liquid Dump