Liquid valves are a critical component in the next generation of analytical equipment used for clinical diagnostics, analytical chemistry, environmental monitoring, agent detection, and other life science applications.
To meet customer’s needs, lab managers want smaller-size diagnostic and analytical equipment with improved sensitivity and reduced reagent consumption—as well as lower operational costs. Finding the balance between improving system performance and managing the bottom line is a challenge for any design engineer in the laboratory instrumentation market space.
Two methods can reduce operational costs:
Engineers can reduce reagent consumption by incorporating smaller-diameter channels in manifolds—sometimes to microcapillary sizes—as well as selecting components with low internal volumes. This reduces the total volume of internal space in which fluids can flow. Because reagents are generally incompressible liquids, however, this solution drives up operating pressures, which can be a big problem for valves.
Liquid isolation valves can help boost throughput and reduce reagent consumption. They have design features that help isolate the reactive fluids from valve components, ensuring long-life valve performance in the application. Liquid isolation valves are small in size, compatible across a wide range of chemistries, and deliver fast response times, which helps reduce the total volume of reagent consumed. They are also designed to minimize the total internal volume and leak to ensure the least amount of reagent consumption in the application.
A new high- pressure, high-flow liquid isolation valve, Parker’s R9 miniature diaphragm isolation valve satisfies the unique needs of modern instrumentation design. At 9 mm in width, it can be efficiently mounted at point-of-dispense in laboratory instruments. It helps increase throughput in laboratory applications by maintaining a response time, from closed to open, of 18 msec or less. This quick response allows device designers to rapidly cycle the valves for dispense purposes, minimizing the time needed to prepare samples for evaluation.
The low internal leak rate ensures that fluid isn’t unnecessarily flowing through the machine unless the valve is specifically actuated to provide flow. Its low internal volume reduces the amount of fluid that can be sitting in the valve at any given time.
The R9 valve also has a much higher pressure rating than other liquid valves of its size, without sacrificing orifice size and flow to achieve it. This higher pressure rating is important in the design of new analyzers as OEM designers continue designing manifolds with smaller passageways.
Smaller passageways require higher pressure to deliver equivalent flow rates while maintaining volumes required by the various chemistries involved in a particular test. The higher pressure rating of the R9 liquid isolation valve allows designers to use these smaller passageways, minimizing the amount of reagent used at each step of the analysis process.
— Jonathan DeSousa, Precision Fluidics Division Applications Engineer
The R9 valve has a variety of configurations for flow and pressure, with pressure capability up to 100 psi (6.8 bar).
The R9 liquid isolation valve meets many key regulatory requirements, allowing designers to focus on system design without worrying about whether or not this key component will cause issues when it comes time to certify their devices. The R9 valve is both RoHS- and Reach-compliant and also complies with many CE criteria.
An advanced component, the R9 valve gives design engineers more freedom to expand the functionality of their products and still reduce operational cost. Its high-level performance and pressure ratings make it an ideal component for microcapillary flow channels and lab-on-a-chip (LOC) disposable testing technologies.
In an era when engineering staffs seem to shrink as much and as quickly as the instruments they design, it helps to work with multi-faceted and experienced component suppliers. Precision Fluidics Division designed the next generation of liquid-handling products critical to the advancement of new diagnostic and analytical technologies, including valves, pumps and dispensing solutions. To speak to an engineer, call  603-595-1500.
Article contributed by senior product manager Don McNeil and Richard Whipple, marketing communications manager, Precision Fluidics Division, Hollis, New Hampshire.