281.491.2331 13839 West Bellfort Street Sugar Land, TX
281.491.2331 13839 West Bellfort Street Sugar Land, TX
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Straight to the (Sample) Point

For real-time natural gas analysis of high-volume lines, you need a sample probe that can deliver a continuous supply of representative samples to your analyzer at the appropriate pressure. The Welker Original IRD Probe Regulator mounts directly to a hot tap or mating flange on your depressurized pipeline and has a fixed insertion length to extract the most representative sample from the center one-third of the source stream.

Where to Use

  • Natural Gas Sampling: Upstream of an analyzer as a standalone pressure control device or part of a conditioning system; natural gas pipelines that can be depressurized for probe installation or removal

Welker Original
Data SheetIRD
Complies WithAPI 14.1, GPA 2166, ISO 10715


Sample the Center One-Third

Off The Wall

Avoid the pipe walls and get to the heart of the source stream. Extending into the center one-third of your pipeline, the IRD captures samples representative of the flowing stream and leaves free liquids behind.


Sample Regulation in Full Flow

No Time to Lose

When inserted into the center one-third of your pipeline, the tip of the IRD regulates your sample under flowing conditions. In-pipeline pressure regulation and the low internal volume of the IRD reduce lag time and get your sample to the analyzer faster. With less time in the sample line, ambient conditions don’t have the opportunity to negatively affect your sample.

Pipeline Connection Options

What's Your Type?

NPT or flanged? With a variety of sizes and ratings from 150 up to 2500 ANSI available, Welker can make the connection.

Thermal Energy Transfer

Take Some Heat

Thermal fins add surface area to the probe tip, allowing pipeline gas to transfer some of its thermal energy to the regulated sample. This additional heat mitigates the cooling caused by pressure drops (Joule-Thomson effect) and helps prevent the sample from condensing.

Precise Regulator Settings

Fine Adjustment

Analytical devices require samples to be injected at a controlled pressure considerably lower than pipeline pressure. Capable of precise settings at low output pressures, diaphragm-operated IRDs keep your analysis going and protect your sensitive equipment from costly damage and downtime caused by high or fluctuating sample pressure.

Spring Range Kit

Kit and Caboodle

Add the Welker Spring Range Kit to your IRD-4SS purchase, and you’ll further increase its functionality. With a set of three springs to choose from, you can easily change the pressure control range of the IRD-4SS for a new application.


IRD Probe Regulator
Materials of Construction316/316L Stainless Steel, PTFE, and Viton®
Others Available
ConnectionsOutlet: 1/4" FNPT
Pipeline: 1/2", 3/4", 1", or 2" MNPT
Output RangeIRD-4: 0-25 psig, 0-50 psig, 20-100 psig, 75-200 psig
IRD-6:,/b> 250-1500 psig
Insertion Length2.2" Standard for 2" and 3" Pipe
3.6" Standard for 4" and 6" Pipe
5.9" Standard for 8", 10", and 12" Pipe
Others Available
3.6" Standard for 4" and 6" Pipe
5.9" Standard for 8", 10", and 12" Pipe
Others Available
Flow Coefficient (Cv)IRD-1, IRD-2, and IRD-6: 0.092
IRD-4: 0.138
OperationIRD-1 and IRD-4: Diaphragm-Operated
IRD-1, IRD-2, and IRD-6: Piston-Operated
Operating PressureIRD-1, IRD-2, and IRD-6: 5000 psig @ -20 °F to 100 °F
IRD-4: 3600 psig @ -20 °F to 100 °F
OptionsExtreme Service Tip
Insulation Blanket
Pre-Set Regulator
Pre-Set Relief Valve
Pressure Gauge
Relief Valve
CE Compliance
CRN Certification