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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inFlow™ Lite

Where to Use

  • Inline composite sampling of NGLs, LPGs, gasoline, diesel, and biodiesel
  • Inline composite sampling of light viscosity crude oil and condensate: install downstream of a static mixer for accurate BS&W analysis
  • Bypass composite sampling of NGLs, LPGs, gasoline, diesel, and biodiesel in applications where sufficient flow is guaranteed
inFlow Lite


Welker Original


High Flow Composite Sampler

The Welker inFlow™ Lite is a double-acting inline sample pump designed to take quality samples of high flow condensates and natural gas liquids (NGLs) proportional to flow. Connect a solenoid, controller signal, pneumatic or hydraulic supply, and sample container to this direct-mount sample pump, and you’ve got a complete liquid sampling system.

Industry StandardsAPI 8.2 / ASTM D4177
Fresh Off the Pipeline

Collect Representative Samples

A direct mount sample pump, the inFlow™ Lite eliminates long tubing runs that impact the timeliness and representativeness of samples. Differential pressure created across the outlet and return ports results in a product circulation loop between the pipeline and the sample pump. The close proximity to the process and product circulation loop created by the ports ensure fresh product is continually presented to the sample pump.

Self-Cleaning Filter
Keep it Clean

Self-cleaning Filter

With the inFlow™ Lite, there’s no need for a costly upstream filter. The removable internal filter element effectively separates entrained particles or sediment from the process fluid. The turbulent flow through the body of the sample pump continuously cleans debris from the filter and returns it to the pipeline, saving you the hassle and cost of filter maintenance.

Outer Limits

External Sample Volume Adjustment

With an externally adjustable sample volume, the inFlow™ Lite can be easily set from 0.25–7.50 cc to suit your sampling requirements. This larger range of sample volumes means the sampler does not have to be operated as fast as similar samplers, which in turn prevents wear and tear.

External Adjustment
Without Interruption

Easy Maintenance

There’s no need to depressurize your pipeline and remove the inFlow™ Lite for standard maintenance. Simply close the valves on the body to isolate the sample pump from process pressure and unscrew four nuts for safe and fast removal of the top assemblies.

Timely Leak Detection

Watch Leaks Like a Hawk

Install the patent-pending Welker LeakHawk™ Leak Detection Manifold to the inFlow™ Lite to catch and proactively repair pump seal leaks before fugitive emissions enter the atmosphere. 

Plus Welker

You Plus Welker™

Let us tailor a turnkey system to your unique application with our Plus Welker™ line.


inFlow™ Lite Sample Pump
 inFlow Lite
Materials of Construction316/316L Stainless Steel Wetted Parts, Aluminum, PTFE
Seal MaterialViton®
Pipeline Connection 3/4" MNPT
Insertion Length Options1.5"
Injection Volume 0.25 - 7.50 cc With Volume Indicator Rod
Operating Pressure 2160 psig MAOP @ -20 °F to 120 °F