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grab sampling systems

Swagelok® Grab Sampling Systems

Customizing Swagelok® grab sampling systems allows for safe, efficient sample capture while meeting your specific plant application needs. The panels are available in a variety of configurations and advanced features.

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Configurable, Local, Reliable Grab Sampling Panels for Gas and Liquid Service

We offer fully configurable, locally built and supported, and reliable grab sampling assemblies in a variety of configurations with advanced features intended to help you safely capture representative samples of liquid or gas from your process lines. Whether you want closed-loop sampling into pressure-rated sample cylinders or simply want to collect process fluid into lower-cost glass laboratory bottles for analysis, we offer ideal sampling panel options that are safe, intuitive, easy to maintain and can be ordered as a single part number.

Swagelok Grab Sampling Panels

grab sample module

Grab Sample Module

The Swagelok® grab sample module (GSM) is a closed-looped sampling system that pulls from a positive-pressure process and returns back to the process at a lower pressure location (e.g., upstream of a pump) by using differential pressure to drive the fluid through the system. Samples are deposited into durable, pressure-rated metal grab sampling cylinders (GSC) that prevent the sample from escaping, protecting operators.

Features of the GSM

  • GSM panels feature a switching valve configuration with two or three Swagelok® 40G series ball valves, allowing for simultaneous control of fluid routing. These configurations reduce the number of steps required and give a clear indication of sequencing, reducing the likelihood of errors.
  • A GSC is docked and process fluid is continuously circulated within to maintain process conditions. A GSC—available in various configurations—is required for every GSM system and should be ordered separately when purchasing a new GSM.
  • The circuit draws a flow path that connects to the sampler then returns to the process or flare. The GSM can be left in the bypass or sample position indefinitely, keeping transport lines fresh and ready for sample capture.
  • A rupture disc is an available option for every GSM system, and a relief valve can also be added to sampling systems where there is added overpressure concern. Each sampling system is built with Swagelok® tube fittings to reduce potential for leaks.
grab sample liquid systems

Grab Sample Liquid Systems

The Swagelok® grab sample liquid (GSL) is a liquid-only sampling system for drawing fluid into a non-pressure-containing bottle with a self-sealing septum cap in applications where the process fluid is not at risk of fractionating when stored at atmospheric pressure.

Features of the GSL

  • Fixed-volume Swagelok GSL systems use the same switching valve as a GSM system to provide simplified operation for complex tasks. Like the GSM, GSL systems are assembled with Swagelok tube fittings to avoid the potential leak points of NPT fittings.
  • The GSL can use lower-cost glass or polyethylene laboratory bottles to draw and store samples. Using bottles provides immediate feedback on the visual quality of the sample stream.
  • Samples can be drawn and transported without the risk of spillage or evaporation. A spring-return handle on the sample drawing mechanism prevents unintentional dispensing.

Grab Sampling Valve

Overcome the safety, maintenance, and quality challenges associated with standard bottle sampling by adding a Swagelok® grab sampling valve to your fluid system. Our leak-free design eliminates rubber O-rings by using a Swagelok® tube fitting to attach the needle assembly to the valve body.

Features of the Grab Sampling Valve

Easy Needle Replacement

Simply tighten the tube fitting nut to create two all-metal seals.

Improved Needle Design

A pencil point needle assembly pierces without coring the septum, minimizing clogged needles and leaking sample bottles.

Interchangeable Shrouds

We offer a variety of shroud options, including custom configurations to match non-standard sample bottles.

Elastomer-Free Design

By eliminating rubber O-rings, you can minimize the potential for system leaks while reducing your maintenance inventory.

Spring-Return Handle

When the Swagelok grab sampling valve is specified with a spring return handle, the valve automatically moves to the closed position when the handle is released, ensuring you collect the sample amount that you need.

Designed by Swagelok Engineers. Optimized for You.

All Swagelok grab sampling systems are designed to protect both your personnel and your profitability, then configured locally by fluid system specialists to meet your specifications.


Designed for Safety

Swagelok grab sampling systems separate the process pressure from the sample bottle and user, preventing overfilling and overpressure conditions. Our panels are also designed with features to minimize the opportunity for operator error, such as a spring-return handle on the sample draw mechanism of the GSL that prevents unintentional dispensing.

ease of use

Designed for Ease of Use

Swagelok grab sampling systems are designed to reduce the number of sequencing steps required for sampling and are built for streamlined maintenance, as well. A switching valve configuration on GSM and fixed-volume GSL panels allows for simultaneous control of fluid routing and gives a clear indication of sequencing to the operator and components such as gauges can be isolated during maintenance to minimize downtime.

Swagelok grab sampling systems are designed for reliable results

Designed for Reliable Results

Closed-loop GSM sampling panels provide fresh samples to cylinders that hold samples at the same process conditions that existed during sampling, giving confidence that the sample is representative. A GSL can use glass laboratory bottles that provide immediate feedback on the visual quality of a sample stream. All our grab sampling panels are assembled with Swagelok tube fittings, reducing potential leak points.

Convenient Standard Assemblies Configured to Meet Your Needs

Both GSM and GSL sampling systems panel types are available in fixed-volume versions that separate the process pressure from the sample bottle and user, preventing over-filling and overpressure conditions. This table provides a summary of common system criteria and the grab sampling system recommended for the listed combinations.

recommended grab sampling system based on system criteria

Swagelok grab sampling systems can be customized with a variety of accessories to suit your operations, including additional instrumentation, sample coolers, automation, exotic alloys, different mounting options, and more.

Local Assembly and Support. Reliable Solutions Built to Last.

Your local authorized Swagelok sales and service center team will work closely with you to determine the type of panel and the proper configuration to meet your sampling system needs. Each grab sampling panel will be built to your specifications at your local Swagelok sales and service center by experienced fluid systems technicians. All Swagelok grab sampling assemblies are rigorously tested and are backed by the Swagelok Limited Lifetime Warranty.

Accessible Grab Sampling Support

When you decide to invest in Swagelok® grab sampling panels to bring standardization and reliability to your sampling operations, your local authorized Swagelok sales and service center team will work with you to determine the right type of panel and the proper configuration to meet your needs. Each grab sampling panel will then be built to your specifications at your local Swagelok sales and service center by experienced fluid system specialists, and the same team will provide ongoing support for your new system in the future.


What to Expect When Ordering Swagelok Grab Sampling Systems

The process of identifying, customizing, and maintaining the right grab sampling solutions for your facilities looks like this:

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Want assistance finding a system design that will yield repeatable, representative samples quickly and cost-effectively? A team of sampling specialists can evaluate your current sampling system and assess your needs as necessary. If you already have a specification or design in mind, you can skip this step. Alternatively, if you would like an even deeper analysis of your sampling systems and practices, our field engineering team can visit your facilities to provide Swagelok® grab sampling evaluation and advisory services that help you detect and fix sampling deficiencies, yielding:

  • Improved operational performance
  • Mitigation of potential safety and environmental concerns
  • More representative samples on a regular basis

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Our team will take you through a checklist of details to help you select a sampling panel that meets your needs. Based on the established parameters, a certified Swagelok engineer will review your information and recommend the right panel for you. We evaluate criteria including:

  • Temperature
  • Pressure
  • Phase
  • Container type
  • Materials of construction
  • Installation location

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Using our standard panel designs as a platform, we can work with your team to customize your solution:

  • Substitute comparable Swagelok and non-Swagelok products
  • Add valves, flowmeters, and other products within the existing schematics
  • Make changes in layout and structural changes/additions
  • Convert to larger/smaller tube size (or metric)
  • Suggest alternative materials of construction
  • Discuss flow/pressure drop calculations
  • Suggest sizing of sample coolers/heaters and enclosure heaters

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We take the work of sampling system assembly off your team, fabricating the system and testing for reliability. Every local Swagelok technician undergoes comprehensive training and certification to ensure your sampling panel adheres to strict guidelines and to your specifications, and our certified engineers will monitor each step of the process.

  • Every Swagelok grab sampling system is shell-tested at the selected gauge pressure
  • Additional testing is available upon request
  • All Swagelok products are backed by the Swagelok Limited Lifetime Warranty

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We provide hands-on training on grab sampling system use and maintenance for your technicians once your panels are assembled. We can also equip your team with the knowledge to prevent, diagnose, and eliminate costly issues with Swagelok® sampling system training based on the teaching of industry expert Tony Waters:

Trust an Industry Leader in Sampling. Trust Your Results.

Learn more about the benefits of Swagelok grab sampling solutions and how the right local support by sampling system specialists can provide value to your organization.


View our Application Guides

Locate detailed information about our assemblies.

Swagelok grab sampling evaluation and advisory services

An Introduction to Grab Sampling

Learn about grab sampling best practices for both gaseous and liquid fluid system media, the characteristics of well-designed and easily operable grab sampling systems, and how to reliably achieve grab sampling accuracy.

Read the White Paper

Swagelok Resources Curated for You

Engineer tests a Swagelok grab sampling panel
Best Practices for Sampling Gases and Volatile Liquids

Read about common challenges associated with volatile liquid and gas grab sampling and learn to overcome them by using the right techniques and appropriate equipment.

Engineer tests a Swagelok grab sampling panel
Liquid Grab Sampling Strategies to Control Costs

Discover several strategies to help drive down costs and minimize errors in your liquid grab sampling processes as you validate process conditions and analyze end product quality.

Swagelok field engineer inspects a grab sampling panel
How to Fix Common Grab Sampling Deficiencies

There are several common fluid systems that successful plant operation depends on, and outsourcing their fabrication can be highly beneficial if you are short on resources. Learn how it works.

Swagelok grab sampling panel
Grab Sampling 101: Reducing Plant Costs

Grab sample systems allow for safe, efficient sample captures—validating your product’s chemical composition. Learn how to improve your closed loop system’s reliability while reducing plant costs with basics from the experts at Swagelok.

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