Today, gas chromatography (GC), mass spectroscopy (MS) and similar life science instrumentation are contributing to results in drug discovery and development, forensics labs, and the next generation of analytical chemistry research across the world. Lab managers are increasingly focused on efficiency and accuracy while keeping operational costs in check. They want analytical equipment that is more sensitive, smaller, flexible and cost-efficient. To meet their needs, OEM design engineers are challenged with finding the balance between improving analytical instrument performance and managing the bottom line.
From a fluid and gas handling perspective, engineers can meet instrument design requirements, improve instrument sensitivity and control costs by selecting valves that are optimized for size, weight and energy efficiency, yet also deliver consistent, high performance.
A new level of control
Parker has recently introduced a new miniature proportional valve designed specifically for analytical chemistry gas flow applications. The VSO® LowPro GC offers a new level of analytical performance for low flow control, maximum allowable leakage rate, and analytic service cleanliness to improve the sensitivity of next-generation analytical instruments, reduce sample noise, and increase signal detection capabilities.
The VSO® LowPro GC was designed for reliability and manufacturability. The latest finite element analysis (FEA) simulation tools were used to reduce the number of parts, size and weight of the valve's internal components – allowing for more repeatable production and a smaller, lighter design. Additional optimization efforts included dynamic, non-linear mechanical analyses, computational fluid dynamics analyses, and electromagnetic analyses, resulting in a valve that is half the size of most existing proportional valves on the market.
Low power consumption
The mechanics of the proportional spring were enhanced using dynamic mechanical analysis software to provide the minimum amount of resistance needed to combat both fluid flow forces and solenoid forces. This resulted in a valve that has very smooth, linear flow control while minimizing the total amount of power needed to move the internal components.
Fast response time
The magnetic circuit was refined using finite element analysis simulation software to decrease air gaps and focus the field strength uniformly around the moving components. This optimization combined with component size reductions has resulted in a very high performing, fast response solenoid design. This improved response time allows the flow of the valve assembly to be more consistent because the valve can keep up with frequent changes in control currents which reduces flow overshooting – especially at low flow ranges.
One valve solution
The VSO LowPro GC valve was designed with 0.007” (0.18mm) and 0.011” (0.28mm) orifices to achieve the balance needed for a one valve solution. It can be used with a variety of gas types, presenting anti-leak capabilities, flow vs. mA control gain and meets the maximum flow and pressure requirements needed in a laboratory GC application. This one valve solution effectively controls large molecule, higher flow rate conditions while also having the capability to control the small molecule size, low flow rate conditions.
Parker Precision Fluidics has been partnering with OEMs in the field of analytical chemistry for over 30 years. Based on that experience, we were able to perfect fluidic control elements that are critical to demanding material science and cleanliness applications. In material science applications, when we select an internal sealing elastomer – we work to understand not only the base material, but different curing agents and curing times. We design our seals by optimizing those variables to reduce outgassing from the elastomer to reduce any potential impact on sample noise. Additionally, for over 20 years Parker Precision Fluidics has implemented a proprietary ultrasonic cleaning process to clean all parts in the fluid wetted path to ensure that we reduce hydrocarbon content and particulates on our parts to levels that have proven to be optimized for analytical service clean applications.
For more information on the VSO® LowPro GC Valve and how it improves signal detection in next
generation life science instruments, download our white paper.
This blog was contributed by Sam Ruback, marketing development manager, Parker Precision Fluidics Division.