The Lee Company Electro-Fluidic Systems Group has been an industry leader in electromechanical valve and pump technology for over three decades. Manifolds offer several advantages compared to just connecting discrete components together with tubing, such as fewer leakage points, lower internal volumes, easier assembly into the instrument, and higher reliability. Our expertise in fluidics is drawn from a solid understanding of the application and the components involved. We can incorporate solenoid valves, pumps, passive components (i.e. restrictors) and active components (i.e. transducers) into a complete assembly that has been functionally tested per the application requirements. The different manufacturing techniques used to create such manifolds include conventional, multi-layered, ant farm, combination and injection manifold.
The conventional approach to machining a manifold is typically used when the valve count is minimal and the flow paths are straightforward. The design pattern of drilled passages enables you to locate valves as desired, with some limitations because the drilled passages must be straight and it requires the plugging of superfluous construction passageways. Integrating miniature valves into a common fluid manifold using conventional cross-drilled machining is a major step in the direction of simplifying otherwise complex valve and fluid passage configurations that once required numerous tubes from point to point.
The image above illustrates a conventional manifold design populated with LHD Series solenoid valves (Plug-In Style) mounted onto a printed circuit board. Equipped with barb ports to accommodate soft tube connection, the subsystem can be easily integrated into any unit.
A multi-layered manifold is typically used when the functional requirements are more complex, which usually involves a higher valve count. This type of manifold design involves stacking together multiple layers of plates containing different machined or milled passages. The different plates are then bonded (epoxy, diffusion or solvent weld) together which allows the valves, pumps, and other fluidic sub-components to be located where appropriate for a specific application.
The image above shows a multi-layered manifold design populated with LFV Series solenoid valves.
The Ant Farm Technique involves machining a series of intricate flow paths or channels into the face of the manifold. After the machining operation, a plate is bonded over the flow passages to complete the circuit. In complex applications, the channels can be milled into more than one face of the manifold block. This manifold machining technique further reduces the overall manifold size compared to the other technologies. This technology also lends itself towards building a modular design. The modular design includes provisions in the near fluid passage for O-rings to provide a seal between different sections of the manifold when mounted together. This erector-set approach to manifold construction gives the designer more flexibility, especially if the application requires a distribution plate to redirect or prevent flow from one passage to another between sections. It also allows the designer to use a spacer plate to increase dimensions between sections when an oversized component or obstruction must be accommodated on the mounting surface.
This manifold design capitalizes on the use of our Ant Farm Technique integrating multiple styles of LHD Series valves (plug-in and face mount) in order to accommodate a system's specific space constraints and flow schematic requirements. The intricate flow paths that complete the internal circuit are showcased in the image on the right, where the bond plate has been partially cut away.
This manifold design exemplifies a higher degree of capability using our Ant Farm Technique together with several LHD Series solenoid valves and other critical components (pressure transducer and regulator).
This complex manifold design demonstrates taking a modular approach while also employing our Ant Farm Technique. Four valve modules are mounted onto a distribution plate and o-rings with integrated screens are used to ensure a proper seal between the different manifold sections.
Combination manifolds are used to incorporate discrete components into a single unit. The Lee LPV Series pumps have a large machined port head. Customization of this port head can incorporate solenoid valves, connections and sensors into a single package. This technique reduces the number of connections, the need for a second manifold and the overall package size. Combining several discrete components into a single one also reduces assembly time during instrument production.
This manifold design demonstrates another level of capability where LHD Series solenoid valves can be integrated into an LPV Series pump with a custom port head.
Lee injection valves minimize the fluid between the valve seat and the flow stream. This in turn minimizes carry over volumes. Staggering the valves on a multi-face manifold allows closer spacing and further reduces the length (thus volume) of the main flow passage.
The image above illustrates the use of our VHS Series solenoid valves in a custom manifold design.