GSS-4

Vanishing Chamber™ Positive Displacement Pump

Fully displaces every sample grab into the connected cylinder — no residual gas left in the collection cup — so each sample is complete, uncontaminated, and ready for analysis.

Fresh Sample System™ — Self-Purging Design

Automatically purges stale gas from the sample path before each actuation, ensuring every grab reflects current pipeline conditions — not the previous cycle.

Direct Probe-Mount Installation

Mounts directly to the pipeline via a Welker Sample Probe — eliminating long sample tubing runs that delay sample capture and compromise representativeness.

Center-Third Pipeline Sampling

The probe extends into the center one-third of the pipeline cross-section — the zone required by API 14.1 — capturing a truly representative sample of the flowing gas stream.

Wet Gas Compatible with LE-2SSKO Liquid Eliminator

For wet gas applications, the patented Welker LE-2SSKO probe-mounted liquid eliminator knocks free liquids out of the sample stream and returns them to the pipeline — keeping the sample in the gas phase.

Compatible with Single Cavity & Constant Pressure Cylinders

Works with both Welker SC single cavity cylinders for dry gas and CP-2 constant pressure cylinders for wet or liquids-rich streams — covering the full range of natural gas sampling applications.

Cylinder Manifold & Bracket Included

Ships standard with a manifold for single cavity cylinders (keeping them vertical for correct filling and purging) and a mounting bracket for constant pressure cylinders — no additional hardware required.

Flexible Actuation — PLC, Analog, or Digital Signal

Connect to a PLC or SCADA system, or use the optional Welker 4P Sample Frequency Controller on analog or digital signal. An optional AC-to-DC converter covers sites without a direct current power supply.

Resilient Chamber Material for Long Service Life

The Vanishing Chamber™ is made from durable, resilient material that reliably springs back to its original shape actuation after actuation — delivering consistent grab volume over the full service life of the sampler.

API 14.1, GPA 2166 & ISO 10715 Compliant

Meets all major natural gas sampling standards — so the samples you collect satisfy custody transfer documentation requirements and stand up to audit review without modification or exception.