The Monitor

Production Process Insights

Safely Sample from Hydrocarbon Tanks with Low-E Samplers

Posted by Randy Cruse on 6/28/21 8:00 AM

low emission tank sampling

Sampling from tanks can be dangerous due to concerns with vapors under pressure and process containment. However, by implementing Low-E samplers and applying best practices, producers can protect personnel, maximize quality and ensure uptime.

The Hazards of Tank Sampling

Sampling liquids from static pressure tanks identifies the characteristics of the product in preparation for refining. In this process, the liquid is often accessed from the tank through a thief hatch, with closable external access points allowing workers to manually sample the product via a sampling container and long string method.

However, according to Occupational Safety and Health Administration (OSHA), workers at hydrocarbon extraction sites could be exposed to vapors, oxygen-deficient atmospheres, and fires or explosions when they open thief hatches and manually collect samples. The organization identified nine fatalities over five years associated with working close to open hatches of crude oil production tanks.

In addition, it’s challenging to generate flow from tanks, and operators run the risk of discharge or blowback. Plus, liquids being sampled are often held under multiple pressures. Operators need to know what the pressure is and how it will be impacted when extracting a sample.

That’s why OSHA recommends that producers implement alternative sampling procedures that allow workers to take samples without opening the tank hatch.

One popular option is to retrofit existing tanks with dedicated sampling ports, also called tank sampling taps, that eliminate the need to routinely open thief hatches to collect samples and minimize worker exposures to hydrocarbon vapors.

However, low emission sampling systems offer enhanced safety and reliability, making it the preferred method for sampling hydrocarbon tanks. With this method, operators can take a sample at grade, avoiding exposure to vapors and the string and container method mess.

Ensure safety with Low-E sampling systems

Operation teams can mitigate risks and follow OSHA’s recommendation by transitioning to a low-emission (Low-E) closed-loop sampling system. These systems are simple, safe and accurate ways to manage representative sampling in liquid tanks. Low-e sampling, combined with proper staff training, can help maximize sampling accuracy while minimizing risks to people, equipment, and the environment.

Safety first. Low emission systems keep dangerous liquids and gases contained by producing
a sample through a series of valves and vents. This containment keeps plants compliant with stringent OSHA and EPA requirements that are the workers' benchmarks and environmental safety. Further, they eliminate VOC emissions and keep the sample volume small to reduce the amount of waste.

Simple operation. Low-e panels provide a simplified system that is easy to use and saves a considerable amount of time without compromising accuracy while creating a greater level of safety and reliability in the sampling process.

Accurate results. Low-e systems are designed to pull fresh material directly from the tank for the most precise representative samples. Because of this, there’s no guesswork as to age or potential detrimental exterior impact. Test results are consistent and reliable.

No matter what method producers choose to reduce the risks during sampling, each worker should undergo safety and sampling training to execute sampling effectively. This training ensures reliable performance to minimize downtime, minimize personnel injury, and maximize efficiency, productivity and product quality.

Sentry goes beyond sampling products to provide our customers with the technical expertise they need through training, consulting and technical assistance.

Contact us at +1-262-567-7256, or complete our online contact form for more information.

Topics: Downstream, Liquid & Slurry

Written by Randy Cruse

Picture of Randy Cruse
As Senior Service Manager, Randy dedicates his lengthy career to developing and delivering service programs designed specifically for refineries and their sampling programs. He understands the risks and safety requirements that come along with being a service provider in the Oil & Gas industry and brings that expertise to each and every call.