Open-Loop Sampling System Failures: How—and Whether—to Choose Alternatives

Ensuring safety compliance during grab sampling is mission-critical to smooth petrochemical plant operations. But plants in the California Bay Area face particular challenges when it comes to meeting health, safety, and environment (HSE) standards. These refineries are some of the oldest in the country, and some have open-loop sampling systems still in service that may be prone to repeated failures.

In the face of repeated open-loop sampling system failures, a cost-benefit analysis of continuing with the current instrumentation versus purchasing a closed-loop sampling system will pose some challenging questions. Fortunately, if you do need to look into alternatives to an unreliable system and have your specs in hand, you will find options that provide an easier means for operators to obtain a sample as well as meet compliance standards.

Open-loop Sampling System Failures Impacting Safety

Many Bay Area refineries are now converted to closed-loop systems as a result of open-loop sampling failures. Operators being splashed with hydrocarbons or vapors during the sampling process resulted in repeated operational safety reviews and prompted this necessary adjustment. If your refinery is still relying on open-loop sampling systems despite their increasingly questionable safety and compliance performance, it may be time to make a change. 

When deciding whether to maintain a current open-loop sampling system or select replacement instrumentation, you’ll need to determine the specific application at hand. If the fluid in the system is simply water, a change in the grab sampling process may not be necessary. But if the open-loop sampling system failures involve volatile or hazardous fluids, deciding whether to opt for a new closed-loop system is crucial. Your decision may depend on your answers to these four operational questions:

1. How is the sampling system performing?

Does your current open-loop sampling system provide you with repeatable and representative samples? Is your current sampling system HSE compliant? 

⇒ If not, it’s time to get in touch with an expert who can check your design for safety and compatibility.  

2. Do the components meet current industry standards? 

Do the components of your open-loop sampling system stack up well against ASME certification and API standards? 

⇒ If you don’t understand the nuances between the two, and how to correctly apply them, the refinery is not well-positioned to prevent eventual failure points.

3. Can the assembly ensure the required specifications?

Has your sampling system been assembled to meet specifications with a material selection that ensures compatibility with the process fluid? If the open-loop sampling station is older, do you still have documentation to show this? 

⇒ If not, you need a grab sampling vendor that can provide CAD drawings, instrumentation diagrams, product test reports, third-party certifications, and more. 

4. Are operational personnel trained to safely use and maintain the open-loop sampling systems? 

Can your sampling-system team prevent, diagnose, and eliminate operational issues that may result in safety compliance issues? If not, do you still have a vendor available that can help close that knowledge gap? 

⇒ It’s important to maintain a relationship with a grab sampling vendor who can be on the ground to train personnel in best practices. 

If you answered “no” to most—or even some—of these questions, it’s time to find out what alternatives you have to your current open-loop sampling systems. Expert consultation with a local grab sampling system vendor may surprise you with unexpected bottom-line benefits that improve safety compliance. 

Proven Expertise Ensures Safe and Accurate Sampling Solutions 

With 50 years of local service to Northern California petrochemical plants, Swagelok engineers can assess, recommend, and configure grab sampling solutions to meet your specific application requirements—and tough California compliance standards—for reducing open-loop sampling failures. While we provide personnel training, our systems are easy to operate, decreasing the possibility of user error or accident, even with customized panels. Outsourcing Assembly Services locally with Swagelok Northern California can also provide cost-savings through shortened turnaround times and simplified logistics. And you’ll also be able to meet safety compliance reviews with rich documentation, all organized for easy team reference.  

To find out more about how Swagelok Northern California can help solve repeated open-loop sampling system failures by providing expert consultation and Assembly Services, contact our team today by calling 510-933-6200!

About Morgan Zealear | Product Engineer, Assembly Services

Morgan holds a Bachelor of Science in mechanical engineering from University of California at Santa Barbara. He is certified in Section IX, Grab Sample Panel Configuration and Mechanical Efficiency Program Specification (API 682), and he is well versed in B31.3 Process Piping Code. Before joining Swagelok Northern, he was a manufacturing engineer at Sierra Instruments, primarily focused on capillary thermal meters for the semiconductor industry (ASML).