Case Study: Oxygen Pressure Control

In the highly specialized field of cryogenic gas processing, the functionality and efficiency of Air Separation Units (ASUs) are crucial. These units, tasked with the critical role of segregating atmospheric air into its elemental gases—including oxygen, nitrogen, and argon—require precise and reliable components to ensure optimal operation. Among these, the oxygen pressure control valve is integral, serving a pivotal role in maintaining the delicate balance needed for the safe and efficient management of gases at sub-zero temperatures.

Enter Air Liquide, a frontrunner in the global gases industry, renowned for its innovative approach to providing gases, technologies, and services across the industrial and health sectors. With a footprint spanning more than 75 countries, Air Liquide leverages its vast expertise to tackle environmental and energy challenges, thereby boosting performance across a wide array of applications.

The challenge:

Air Liquide encountered a formidable challenge in regulating the pressure of gaseous oxygen (GOX) and liquid oxygen (LOX) at the extreme temperature of -321°F across different locations. This difficulty arises because, at such low temperatures, oxygen behaves unpredictably, with slight pressure changes potentially leading to rapid phase changes or volume expansions. This complicates the task of maintaining stable and controlled conditions.

Air Liquide's operational demands were centred on achieving exact flow control and secure tight shutoff mechanisms, essential for ensuring operational safety and enhancing efficiency. These requirements are particularly crucial in the context of cryogenic gases, where precise flow management and the ability to completely halt gas movement are vital to prevent leaks and ensure safe handling of potentially combustible materials.

Additionally, noise reduction posed a significant challenge. This is due to its potential to cause disruptions in environments where maintaining a quiet atmosphere is crucial, such as in close proximity to residential areas or in laboratories where sensitive experiments are conducted.

The sensitive and specialized nature of cryogenics means the majority of off-the-shelf control valves were not fit for these dual purposes. To ensure safety and efficiency, Air Liquide approached Trimteck for a custom-engineered solution.

The solution:

After a detailed consultation process, Trimteck proposed a design for a custom speciality control valve. The Cryogenic OpGL Control Valve, ranging in sizes from 1” to 6” CL300, was specifically designed to meet the rigorous demands of Air Liquide’s cryogenic applications. The valves featured:

• General Service, ST-2 or ST-3 Trim Type: These trims are designed with distinct characteristics to mitigate common issues such as cavitation and excessive noise, which are prevalent in the handling of cryogenic gases. The ST-2 trim, for example, might be tailored to reduce cavitation by managing the pressure drop across the valve more effectively, while the ST-3 trim could be focused on minimizing operational noise through advanced fluid dynamics design.
• Monel Trim Material: Monel, a nickel-copper alloy, was chosen for the trim material due to its exceptional strength and its proven resistance to the extreme temperatures and corrosive properties of gaseous oxygen (GOX) and liquid oxygen (LOX). This alloy is renowned for its durability in harsh environments, making it an ideal choice for maintaining integrity and performance in the demanding conditions of cryogenic operations.
• CF8M Body Material: CF8M, a stainless steel alloy, is chosen for the valve body material because of its notable resistance to cryogenic temperatures. This alloy, part of the ASTM A351 standard, ensures both the longevity and reliability of the valve's structure in demanding conditions.
• OpTK25™ or OpTK50™ Piston Cylinder Actuators: Engineered to deliver the robust force required to achieve an airtight seal and maintain precise flow control, even under the demanding conditions characteristic of cryogenic applications.

Unparalleled expertise in cryogenic control valves

Our innovative Cryogenic Control Valves are engineered to tackle the most challenging applications, ensuring precision, safety, and efficiency at extreme temperatures. With a track record of success with industry leaders like Air Liquide, Trimteck is your go-to partner for advanced cryogenic solutions. Discover the difference custom speciality control valves can make in your operations.

Contact us today to explore how we can support the requirements of your cryogenic application.