The Monitor

Production Process Insights

Why Should Refineries Upgrade to Low-Emission Sampling?

Posted by Jeff Zweig on 12/15/15 10:30 AM


Bucket sampling in petrochemical refineries isn’t new, and it isn’t very effective. Bucket sampling involves an operator simply walking up to a spigot, turning it on and collecting the sample in a bucket or other container. The samples pulled from a spigot may not be fresh or representative, or they could be impacted by exterior elements like fluctuating temperatures - both of which could foul the sample. Sampling this way involves additional significant safety risks to the operator, which can cost in manpower and money. Factor in the time it takes an operator to capture a sample and the logistics involved in getting it to the lab, and soon what was thought to be an easy and cheap sampling method is anything but.

Plants can eliminate the imprecision and headaches associated with bucket sampling by transitioning to a low-emission (low-e) closed loop sampling system, which is safe, simple and accurate.

1. Safety

Worker and environmental safety is always a priority in any industry, but it takes on added importance in a petrochemical refinery. Poisonous gases like hydrogen sulfide are byproducts of the refining process and exposure is an always-present threat. Therefore, using buckets and spigots during sampling is risky because of the potential for spills and prolonged toxic vapor release, both of which can harm operators and the environment.

On the other hand, closed loop systems are completely safe. They keep liquids and gases contained, and operators use a series of valves and vents to control the low e-sampling process. Closed loop systems also comply with the stringent OSHA and EPA requirements that are the benchmarks of worker and environmental safety.

Further, closed loop systems reduce the sample volume from a “bucketful” to anywhere from 2 to 32 ounces. These small samples reduce the amount of waste produced by bucket sampling, removing the need to address how they will handle its safe disposal after testing. 

2. Simplicity

In a busy petrochemical refinery, the last thing that’s needed is a complicated sampling system. Experience shows that the more complex the system, the less likely it is to be used to its potential – if at all. Operators simply don’t have the time to learn the intricacies of a multi-valve panel. And, at times, a multi-valve solution is overkill.

Keep it simple. For example, recently, a customer raised a red flag about an eight-valve sampling panel that was a burden to operate and, frankly, not used because of its complexity. Our answer? We set in one sampling line with one sampler. When it came time for sampling, the operator switched one valve , opened the bottom valve to collect a representative sample, and then returned the valve to bypass mode. Done. Our simplified system was easy to use and saved a considerable amount of time without compromising the sampling process.

3. Accuracy

If your samples aren’t fresh, there’s no point in analyzing them. Say a liquid is sitting in a 50-foot line over a period of days. Even when the operator pulls a sample after letting a spigot run, there’s a good chance that the repeated exposure to the heat of the day or other factors changed the liquid’s properties. It’s not a true representative sample of what’s flowing, and test results will be skewed – wasting time, effort and money. It also jeopardizes the quality and consistency of the end product.

Capturing accurate representative samples isn’t a concern with low-e sampling. Closed loop systems are designed to aid operators in pulling fresh material directly from the flow. There is no guesswork as to age or potential detrimental exterior impact. Test results are reliable. 

Give our team a call at +1-262-567-7256 or complete our online contact form to discuss how Sentry low-E closed loop systems for the petrochemical refining industry can help you achieve safe, simple and accurate sampling results.

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Topics: Downstream

Written by Jeff Zweig

He’s seen it all and designed it all – any application, anywhere. Jeff knows just about everything there is to know about sampling, having been with the company for nearly 40 years. As one of our first employee-owners and knowledgeable sales and application engineers, Jeff can help your plant avoid catastrophes and improve environmental and operator safety by learning about your application and recommending the best sampling and monitoring solutions to meet your needs.

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