Specifying a Grab Sampling System
Specifying a Grab Sampling System
The Swagelok grab sampling systems provide solutions to satisfy gas and liquid non-slurry sampling service in a consistent, reliable package. Two system types allow for capture into one of two types of containers - pressure containing metal cylinders as found in the Grab Sample Module (GSM) or non pressure‑containing glass or polyethylene bottles as found in the Liquid Only Sampling Module (GSL).
Given the wide variety of configurations available, there will be several criteria to consider in order to properly specify a grab sampling system:
- Pressure: Each GSM and GSL system has a maximum rated pressure, not to be exceeded. Note: The use of a rupture disc or relief valve is recommended with chemicals that may rapidly expand and pressurize due to temperature changes.
- Temperature: Each GSM and GSL system has a maximum fluid operating temperature. Note: Some models may have reduced pressure ratings at elevated temperatures. Also, some models may have minimum fluid operating temperatures, below which proper function cannot be assured.
- Phase: A cylinder sampler (GSM) can be suitable for either liquid or vapor systems. A bottle sampler (GSL) may not prevent the release of vapors and is better suited for most non-volatile liquid systems.
- Hazardous/flammable material: The sampling system must provide sufficient protection for the operator and environment from the system fluid. Certain chemicals such as aqueous chlorine and pyrophoric compounds require more stringent leak or chemical protection than may be provided by a Swagelok GSM or GSL.
- Materials of Construction (including coatings, etc.): The materials used in the sampling system must be compatible with the system fluid. The standard material of construction for Swagelok sampling systems is 316 stainless steel. Alternate materials such as brass and alloy 400 are available for some configurations.
- Surface treatments: Surface treatments can reduce the absorption and adsorption of the sample fluid into metallic surfaces, leading to a more representative sample. Electropolished (EP) tubing is available. In addition to or in place of electropolishing, many coatings can be applied to the wetted components: SilcoNert®, Silcolloy®, and Dursan® are frequently requested coatings. Contact your authorized sales and service center for details.
- Purge: Some chemicals may leave residue or contaminate the lines if not flushed from the system. Selecting the purge option provides a means to introduce a purge fluid (air, solvent, etc.) to remove residual contamination from the sample lines.
Looking for a sampling system?
Just fill in the below form and we will come back at the earliest